A student is performing a Benedict’s test on an unknown substance. He adds the reagent (the chemical required to make a color change), and nothing happens. What can he conclude? A- The substance is glucose-based. B- The substance is not glucose-based. C- The test was inconclusive because he needed to also test with iodine or vinegar. D- The test was inconclusive because he forgot to add heat.

Answers

Answer 1

Answer:

The correct answer is : option D. The test was inconclusive because he forgot to add heat.

Explanation:

Benedict's test is a test that is used to confirm the presence of the simple carbohydrates (mono saccharides and some disaccharides). It is a reagent made by mixture of solution of CuSO4 with sodium citrate and Na2CO3.

Benedict's reagent is added to the substance to test and then heated if it turns yellow to orange or red the presence of simple sugar is confirmed.

Thus, the correct answer is : option D. The test was inconclusive because he forgot to add heat.

Answer 2

Answer:

The test was inconclusive because the student forgot to add heat.

Explanation:

If the test revealed it was not glucose, then the student could run these tests. The student, however, does not need these substances to run the glucose test properly.


Related Questions

1. For the following reaction, 4.86 g of magnesium nitride are mixed with excess water. The reaction yields 7.18 g of magnesium hydroxide.
magnesium nitride(s) + water(1) –> magnesium hydroxide (aq) + ammonia (aq)
What is the ideal yield of magnesium hydroxide?
What is the percent yield for this reaction?
2. For the following reaction, 6.41 g of hydrogen gas are mixed with excess nitrogen gas. The reaction yields 26.2 g of ammonia.
nitrogen(g) + hydrogen(g) –> ammonia(g)
What is the ideal yield of ammonia?
What is the percent yield for this reaction?
3. For the following reaction, 3.79 g of water are mixed with excess chlorine gas. The reaction yields 8.70 g of hydrochloric acid.
chlorine(g) + water(1) –> hydrochloric acid(aq) + chloric acid (HCIO3)(aq)
What is the ideal yield of hydrochloric acid?
What is the percent yield for this reaction?

Answers

Answer:

See explanation

Explanation:

1)

Mg3N2(s) + 6H2O(l) ------------> 3Mg(OH)2 + 2NH3(g)

Number of moles of magnesium nitride= mass/molar mass= 4.86g/100.9494 g/mol = 0.048 moles

1 mole of magnesium nitride yields 3 moles of magnesium hydroxide

0.048 moles of magnesium nitride yields 0.048 moles × 3= 0.144 moles of magnesium hydroxide

Theoretical yield of magnesium hydroxide = 0.144 moles × 58.3197 g/mol = 8.398 g

Percent yield= actual yield/ theoretical yield × 100

Percent yield= 7.18/8.398 × 100/1 = 85.5%

2)

N2(g) + 3H2(g) -------> 2NH3(g)

Number of moles of hydrogen gas = mass/ molar mass = 6.41g/ 2gmol-1 = 3.205 moles of hydrogen gas.

From the balanced reaction equation;

3 moles of hydrogen gas yields 2 moles of ammonia

3.205 moles of hydrogen gas yields 3.205 × 2/3 = 2.1367 moles of ammonia

Theoretical yield of ammonia = 2.1367 moles × 17 gmol-1 = 36.3 g

Percent yield = actual yield/ theoretical yield ×100

Percent yield = 26.2/36.3 ×100

Percent yield = 72.2%

3)

3Cl2(g) + 3H2O(l) ------> HOCl3(aq) + 5HCl(aq)

Number of moles of water= mass/ molar mass = 3.79g/18 gmol-1 = 0.21 moles

Since

3 mole of water yields 5 mole of HCl

0.21 moles of water yields 0.21 × 5/3 = 0.35 moles of HCl

Theoretical yield of HCl = 0.35 moles × 36.5 gmol-1 = 12.775 g

Percent yield = actual yield/ theoretical yield × 100/1

Percent yield = 8.70/12.775 ×100

Percent yield = 68.1%

Find the pH of these buffer solutions using the information provided: 1L solution containing 80g of lactic acid (MW

Answers

Answer:

pH of the solution is 2.0

Explanation:

The lactic acid is a weak acid that is in equilibrium with water as follows:

Lactic acid + H2O ⇄ Lactate + H₃O⁺

And Ka for lactic acid: 1.38x10⁻⁴

Ka = 1.38x10⁻⁴ = [Lactate] [H₃O⁺] / [Lactic acid]

Initial concentration of lactic acid is (MW: 112.06g/mol):

80g * (1mol / 112.06g) / 1L = 0.714M

The equilibrium concentration of the species in the equilibrium are:

[Lactate] = X

[H₃O⁺] = X

[Lactic acid] = 0.714-X

Replacing in Ka expression:

1.38x10⁻⁴ = [X] [X] / [0.714-X]

9.8532x10⁻⁵ -  1.38x10⁻⁴X = X²

9.8532x10⁻⁵ -  1.38x10⁻⁴X - X² = 0

Solving for X:

X = -1.0x10⁻². False solution, there is no negative concentrations

X = 9.86x10⁻³M. Right solution.

As [H₃O⁺] = X

[H₃O⁺] = 9.86x10⁻³M

and pH = -log [H₃O⁺] = -log 9.86x10⁻³M

pH = 2.0

pH of the solution is 2.0

Rank the following amine derivatives from highest acidity (lowest pKa value) to lowest acidity (highest pKa value).
Highest acidity
anilinium ion
aniline
ammonium ion
secondary amine
amide
Lowest acidity

Answers

Answer:

anilinium ion > ammonium ion > amide > aniline > secondary amine

Explanation:

Acidity of amine derivatives can derived from their pKa values.

The rule of thumb for acidity with relation to pKa values is that:

As the pKa decreases the acid strength increases and the conjugate base decreases. Similarly, as the pKa increases, the acid strength decreases and the conjugate base increase.

Hence the stronger the acid , the  lower pKa value  and the weaker the acid , the stronger the pKa value.

So the pKa value for anilinium ion = 4.6

ammonium ion = 9.4

Amide = 15

Similarly, for aniline and secondary amine, in order to determine the derivative with the higher acidity, we will consider the electron withdrawing substituent group.

The more difficult the electron are being withdraw from the electron withdrawing substituent , the more acidic the compound.

In aniline , the stabilized benzene ring attached to NH₂ makes it a less electron withdrawing group compared to the straight chains structure found in secondary amine where electron are easily withdraw by nucleophilic substitution reactions.

Thus, from highest acidity (lowest pKa value) to lowest acidity (highest pKa value).

the amine derivatives ranking is as follows:

anilinium ion > ammonium ion > amide > aniline > secondary amine

"What is the difference between the revertible and nonrevertible rII mutants that Benzer generated?"

Answers

The difference is that revertible is u are able to change back and get back what u once had non revertible is the opposite meaning,u can’t have what u once had.

Consider the compound hydrazine N2H4 (MW = 32.0 amu). It can react with I2 (MW = 253.8 amu) by the following reaction 2 I2 + N2H4 ------------- 4 HI + N2 (a) How many grams of I2 are needed to react with 36.7 g of N2H4? (b) How many grams of HI (MW = 127.9 amu) are produced from the reaction of 115.7 g of N2H4 with excess iodine?

Answers

Answer:Cobb

Explanation:What y'all

A student mixes 1.0 mL of aqueous silver nitrate, AgNO3 (aq), with 1.0 mL of aqueous sodium chloride, NaCl (aq), in a clean test tube. What will the student observe

Answers

Answer:

AgCl (silver Chloride) is being precipitated out as white and cloudy crystals.

Explanation:

If a student mixes 1.0 mL of aqueous silver nitrate AgNO3 (aq)  with 1.0 mL of aqueous sodium chloride, NaCl (aq), in a clean test tube.

The sodium chloride is being acidified with dilute trioxonitrate (V) acid. Then a few drops of  silver trioxonitrate(V) is added afterwards. A  white precipitate of silver chloride, which dissolves readily in aqueous ammonia indicates the presence of sodium chloride.

The reaction proceeds as follows:

[tex]\mathtt{AgNO_{3(aq)} + NaCl _{(aq)} \to AgCl _{(s)} + NaNO_3_{(aq)}}[/tex]

From the reaction between AgNO3 (aq) and NaCl (aq), AgCl (silver Chloride) is being precipitated out as white and cloudy crystals.

Draw two constitutional isomers that share the molecular formula C3H8S. Your structures will have the same molecular formula but will have different connectivities.

Answers

Answer:

Two constitutional isomers for the compound C3H8S are shown in the attachment below

Explanation:

Constitutional isomers are isomers that have the same molecular formula but different connectivity. Two constitutional isomers for the compound C3H8S are shown in the attachment below.

As per the concept of structural isomers, the  two constitutional isomers that share the molecular formula C₃H₈S are attached in attachment below.

Structural isomers are defined as the isomers  in which atoms are completely  arranged  in a different order but the molecular formula remains the same.

They are the molecules which have same molecular formula but different  connectivities  of atoms  which depend on the order they are put together. An increase in the number of carbon atoms leads to an increase  in the structural isomers.

Learn more about structural isomers,here:

https://brainly.com/question/33929317

#SPJ6

At what temperature in K will 0.750 moles of oxygen gas occupy 10.0 L and exert 2.50 atm of pressure

Answers

Answer:

406 K.

Explanation:

The following data were obtained from the question:

Number of mole (n) = 0.750 mole

Volume (V) = 10.0 L

Pressure (P) = 2.50 atm

Temperature (T) =.?

Note: Gas constant (R) = 0.0821 atm.L/Kmol

The temperature, T can be obtained by using the ideal gas equation as follow:

PV = nRT

2.5 x 10 = 0.75 x 0.0821 x T

Divide both side by 0.75 x 0.0821

T = (2.5 x 10) /(0.75 x 0.0821 )

T = 406 K.

Therefore, the temperature is 406 K.

Answer: 406 K

Explanation:

We can rewrite the ideal gas law to solve for T:

PV = nRT

T=PV / nR

We are given the following from the problem:

n=0.750 mol P=2.50 atm V=10.0 L

Plugging in our values and using R=0.08206 L⋅atm / K⋅mol we get:

T=(2.50 atm)(10.0 L) / (0.750 mole)(0.08206L ⋅ atm ⋅ mole K) = 406 K

A 1.00 liter flask initially contained 0.24 mol NO2 at 700 K which decomposed according to the following equation. When equilibrium was achieved, 0.14 mol NO was present. Calculate Kc. 2NO2(g) ↔ 2NO(g) + O2(g)

Answers

Answer:

[tex]Kc=0.14[/tex]

Explanation:

Hello,

In this case, for the given reaction, the equilibrium expression is:

[tex]Kc=\frac{[NO]^2[O_2]}{[NO_2]^2}[/tex]

That in terms of the reaction extent [tex]x[/tex] is written as (initial concentration of NO2 is 0.24 M for 0.24 mol in 1.00 L):

[tex]Kc=\frac{(2*x)^2(x)}{(0.24M-2*x)^2}[/tex]

Moreover, since at the equilibrium 0.14 moles of NO are present (a 0.14-M concentration), we can compute the reaction extent as shown below:

[tex][NO]=2*x=0.14M[/tex]

[tex]x=0.14M/2=0.07M[/tex]

In such a way, knowing [tex]x[/tex], we compute Kc as shown below:

[tex]Kc=\frac{(2*0.07)^2(0.07)}{(0.24M-2*0.07)^2}\\\\Kc=0.14[/tex]

Regards.

The kc is 0.14.

Equivalent expression:

Since

[tex]Kc = \frac{[NO]^2[O_2]}{[NO_2]^2}\\\\[/tex]

Here the reaction extent x should be written like the initial concentration of NO2 is 0.24 M for 0.24 mol in 1.00 L.

Now

[tex]Kc = \frac{(2\times\ x)^2}{(0.24M - 2\times x)^2}[/tex]

Since at the equilibrium 0.14 moles of NO are presented so the reaction should be

NO = 2*x = 0.14m

x = 0.07

Now kc should be

[tex]= \frac{(2\times 0.07)^2 (0.07)}{(0.24M - 2\times 0.07)^2}[/tex]

= 0.14

Learn more about equation here: https://brainly.com/question/24710653

If a sample of C-14 initially contains 1.6 mmol of C-14, how many millimoles will be left after 2250 years

Answers

Answer: 1.2 millimoles will be left after 2250 years

Explanation:

Expression for rate law for first order kinetics is given by:

[tex]t=\frac{2.303}{k}\log\frac{a}{a-x}[/tex]

where,

k = rate constant

t = age of sample

a = let initial amount of the reactant

a - x = amount left after decay process  

a) for completion of half life:

Half life is the amount of time taken by a radioactive material to decay to half of its original value.

[tex]t_{\frac{1}{2}}=\frac{0.693}{k}[/tex]

[tex]k=\frac{0.693}{5730}=0.00012years^{-1}[/tex]

b) Amount left after 2250 years

[tex]2250=\frac{2.303}{k}\log\frac{1.6}{a-x}[/tex]

[tex]2250=\frac{2.303}{0.00012}\log\frac{1.6}{a-x}[/tex]

[tex]\log\frac{1.6}{a-x}=0.117[/tex]

[tex]\frac{1.6}{a-x}=1.31[/tex]

[tex]{a-x}=\frac{1.6}{1.31}=1.2[/tex]

Thus 1.2 millimoles will be left after 2250 years

Calculate the amount of heat that must be absorbed by 10.0 g of ice at –20°C to convert it to liquid water at 60.0°C. Given: specific heat (ice) = 2.1 J/g·°C; specific heat (water) = 4.18 J/g·°C; ΔH fus = 6.0 kJ/mol.

Answers

Answer:

The amount of heat to absorb is 6,261 J

Explanation:

Calorimetry is in charge of measuring the amount of heat generated or lost in certain physical or chemical processes.

The total energy required is the sum of the energy to heat the ice from -20 ° C to ice of 0 ° C, melting the ice of 0 ° C in 0 ° C water and finally heating the water to 60 ° C.

So:

Heat required to raise the temperature of ice from -20 °C to 0 °C

Being the sensible heat of a body the amount of heat received or transferred by a body when it undergoes a temperature variation (Δt) without there being a change of physical state (solid, liquid or gaseous), the expression is used:

Q = c * m * ΔT

Where Q is the heat exchanged by a body of mass m, made up of a specific heat substance c and where ΔT is the temperature variation (ΔT=Tfinal - Tinitial).

In this case, m= 10 g, specific heat of the ice= 2.1 [tex]\frac{J}{g*C}[/tex] and ΔT=0 C - (-20 C)= 20 C

Replacing: Q= 10 g*2.1 [tex]\frac{J}{g*C}[/tex] *20 C and solving: Q=420 J

Heat required to convert 0 °C ice to 0 °C water

The heat Q necessary to melt a substance depends on its mass m and on the called latent heat of fusion of each substance:

Q= m* ΔHfusion

In this case, being 1 mol of water= 18 grams: Q= 10 g*[tex]6.0 \frac{kJ}{mol} *\frac{1 mol of water}{18 g}[/tex]= 3.333 kJ= 3,333 J (being kJ=1,000 J)

Heat required to raise the temperature of water from 0 °C to 60 °C

In this case the expression used in the first step is used, but being: m= 10 g, specific heat of the water= 4.18 [tex]\frac{J}{g*C}[/tex] and ΔT=60 C - (0 C)= 60 C

Replacing: Q= 10 g*4.18 [tex]\frac{J}{g*C}[/tex] *60 C and solving: Q=2,508 J

Finally, Qtotal= 420 J + 3,333 J + 2,508 J

Qtotal= 6,261 J

The amount of heat to absorb is 6,261 J

The amount of heat to absorb is 6,261 J.

Calculation for heat:

Heat required to raise the temperature of ice from -20 °C to 0 °C.

The formula for specific heat is used to calculate the amount of heat

Q = c * m * ΔT

Where,

Q =heat exchanged by a body,

m= mass of the body

c= specific heat

ΔT= change in temperature

Given:

m= 10 g,

specific heat of the ice= 2.1

ΔT=0 C - (-20 C)= 20 C

On substituting the values:

Q= 10 g*2.1  *20 C

Q=420 J

Heat required to convert 0 °C ice to 0 °C water.

The heat Q necessary to melt a substance depends on its mass m and on the called latent heat of fusion of each substance:

Q= m* ΔHfusion

Heat required to raise the temperature of water from 0 °C to 60 °C

m= 10 g,

Specific heat of the water= 4.18  

ΔT=60 C - (0 C)= 60 C

On substituting:

Q= 10 g*4.18  *60 C

Q=2,508 J

Thus, Qtotal= 420 J + 3,333 J + 2,508 J

Qtotal= 6,261 J

The amount of heat to absorb is 6,261 J

Find more information about Specific heat here:

brainly.com/question/13439286

What creation would you make if you had access to any of the chemical elements? can someone answer this for me please.​

Answers

Answer:

Depends on the chemicals.

Explanation:

The creation of something depends on the chemical we have. If I have chemicals such as acid and base so I can produce salt and water by mixing acid and base. If I have ethanol, vegetable oil and sodium hydroxide which is  a catalyst, I can produce biodiesel which can be used in vehicles instead of fossil fuel. If I have sodium element and chlorine gas, I can produce sodium chloride also known as table salt.

g The electronic structure of which ONE of the following species cannot be adequately described by a single Lewis formula? (In other words, the electronic structure of which one can only be described by drawing two or more resonance structures?) A) C2H4 B) SO3 2– C) SO3 D) C3H8 E) HCN

Answers

Answer:

C) SO3

Explanation:

Lewis formula shows the bonding between atoms of a molecule and expresses the lone pair present in the atoms.

SO3 or Sulfur trioxide cannot be adequately described by a single Lewis formula because it has majorly 3 resonance structures because Sulfur does not follow the octet rule and can expand electrons in its outer shell.

Hence, the correct answer is C) SO3

The respiration rate of a goldfish is measured. The goldfish is then placed in cold water and the respiration rate is measured again. What is the INDEPENDENT variable?

Answers

Answer:

Temperature of the water

Explanation:

In every study, there must be independent and dependent variables. An independent variable is the variable that is changed in order to obtain a response. In this case, the temperature of the water is being changed, the response in this experiment is the respiration rate of the goldfish.

Thus the respiration rate of the goldfish is the dependent variable because it is controlled by the temperature of the water and changes accordingly.

Summarily, the independent variable is the temperature of the water while the dependent variable is the respiration rate of the goldfish.

A reaction mechanism has the following proposed elementary steps:Step 1: A → B + CStep 2: A + B → DStep 3: 2 A + D → C + EIf Step 2 is the rate-limiting step, what would the proposed rate law for this mechanism be?

Answers

Answer: [tex]Rate=k[A][B][/tex]

Explanation:

Rate law says that rate of a reaction is directly proportional to the concentration of the reactants each raised to a stoichiometric coefficient determined experimentally called as order.

Order of the reaction is defined as the sum of the concentration of terms on which the rate of the reaction actually depends. It is the sum of the exponents of the molar concentration in the rate law expression.

For reactions which takes place in multiple steps are complex reactions and the order is given by the slowest step which is the rate limiting step.

For the given reaction, the rate limiting step is

[tex]A+B\rightarrow D[/tex]

Rate law will be , [tex]Rate=k[A][B][/tex]

Write the half-reactions as they occur at each electrode and the net cell reaction for this electrochemical cell containing indium and cadmium. In(s)|

Answers

Answer:

Oxidation half equation;

3Cd(s) -------> 3Cd^2+(aq) + 6e

Reduction half equation;

2In^3+(aq) + 6e -----> 2In(s)

Explanation:

Since the reduction potentials of Indium and Cadmium are -0.34 V and - 0.40 V respectively, we can see that cadmium will be oxidized while indium will the reduced.

We arrived at this conclusion by examining the reduction potential of both species. The specie with more negative reduction potential is oxidized in the process.

Oxidation half equation;

3Cd(s) -------> 3Cd^2+(aq) + 6e

Reduction half equation;

2In^3+(aq) + 6e -----> 2In(s)

If you had a cup full of methanol and a pool full of methanol, would the mass change?

Answers

Answer:

the mass does not change

Explanation:

Calculate the energy required to heat 1.30kg of water from 22.4°C to 34.2°C . Assume the specific heat capacity of water under these conditions is 4.18·J·g−1K−1 . Round your answer to 3 significant digits.

Answers

Answer:

The energy required to heat 1.30 kg of water from 22.4°C to 34.2°C is 64,121.2 J

Explanation:

Calorimetry is the measurement of the amount of heat that a body gives up or absorbs in the course of a physical or chemical process.

The sensible heat of a body is the amount of heat received or transferred by a body when undergoing a temperature variation (Δt) without there being a change in physical state. That is, when a system absorbs (or gives up) a certain amount of heat, it may happen that it experiences a change in its temperature, involving sensible heat. Then, the equation for calculating heat exchanges is:

Q = c * m * ΔT

Where Q is the heat or quantity of energy exchanged by a body of mass m, constituted by a substance of specific heat c and where ΔT is the variation in temperature (ΔT=Tfinal - Tinitial).

In this case:

[tex]c=4.18 \frac{J}{g*K}[/tex]m= 1.30 kg= 1,300 g (1 kg=1,000 g)ΔT= 34.2 °C - 22.4 °C= 11.8 °C= 11.8 °K  Being a temperature difference, it is independent if they are degrees Celsius or degrees Kelvin. That is, the temperature difference is the same in degrees Celsius or degrees Kelvin.

Replacing:

[tex]Q=4.18 \frac{J}{g*K}*1,300 g*11.8 K[/tex]

Q= 64,121.2 J

The energy required to heat 1.30 kg of water from 22.4°C to 34.2°C is 64,121.2 J

Why will the conjugate base of a weak acid affect pH? Select the correct answer below: it will react with hydroxide

Answers

Answer:

It will react with water

Explanation:

I know this is an older question, but I just wanted to provide the correct answer.

Since we are dealing with a weak base, and the acid is somewhat stronger, it will react with the water molecules to produce hydronium, which will affect the pH of the solution.

The conjugate base of a weak acid affect pH because it will react with hydronium ion.

A weak acid is an acid that does not dissociate completely in water. On the other hand, a strong acid achieves almost 100% dissociation in water.

Acids dissociate in water to yield the hydronium ion and a conjugate base. For instance, the weak acid, acetic acid is dissociated as follows;

CH3COOH(aq) + H2O(l) ⇄ CH3COO-(aq) + H3O+(aq)

We can see that the conjugate base( CH3COO-) could react with the hydronium ions thereby moving the equilibrium position to the left hand side and affecting the pH by decreasing the hydronium ion concentration.

Learn more: https://brainly.com/question/8592296

Missing parts;

Why will the conjugate base of a weak acid affect pH? Select the correct answer below: O it will react with hydroxide O it will react with water O it will react with hydronium O none of the above

Given the data: Ag2O(s), = ‑31.1 kJ mol-1, S° = +121.3 J mol-1 K-1 Ag(s), = 0.00 kJ mol-1, S° = +42.55 J mol-1 K-1 O2(g), = 0.00 kJ mol-1, S° = +205.0 J mol-1 K-1 Calculate the temperature at which = 0 for the reaction, Ag2O(s) → 2 Ag(s) + ½ O2(g). Assume that, since the physical states do not change, and are independent of tempera­ture between ‑50.0 °C and 950.0 °C.

Answers

Answer:

[tex]T=469.1K\\\\T=195.9\°C[/tex]

Explanation:

Hello,

In this case, for the given decomposition reaction, we can compute the enthalpy of reaction considering the enthalpy of formation of each involved species (products minus reactants):

[tex]\Delta _rH=2\Delta _fH_{Ag}+\frac{1}{2} \Delta _fH_{O_2}-\Delta _fH_{Ag_2O}\\\\\Delta _rH=2*0.00+\frac{1}{2} *0.00-(-31.1)=31.1kJ/mol[/tex]

Next, the entropy of reaction considering the standard entropy for each involved species (products minus reactants):

[tex]\Delta _rS=2S_{Ag}+\frac{1}{2} S_{O_2}-S_{Ag_2O}\\\\\Delta _rS=2(42.55)+\frac{1}{2} (205.0)-(121.3)=66.3J/(mol*K)[/tex]

Next, since the Gibbs free energy of reaction is computed in terms of both the enthalpy and entropy of reaction at the unknown temperature, for such Gibbs energy equaling 0, the temperature (in K and °C) turns out:

[tex]\Delta _rG=\Delta _rH-T\Delta _rS\\\\0=31.1kJ/mol-T(66.3\frac{J}{mol*K}*\frac{1kJ}{1000J} )\\\\T=\frac{31.1kJ/mol}{0.0663kJ/(mol*K)} =469.1K\\\\T=195.9\°C[/tex]

Which is within the given rank.

Best regards.

A solution of LiCl in water has XLiCl = 0.0800. What is the molality? A solution of LiCl in water has XLiCl = 0.0800. What is the molality? 4.44 m LiCl 8.70 m LiCl 4.83 m LiCl 4.01 m LiCl

Answers

Answer:

mol LiCl = 4.83 m

Explanation:

GIven:

Solution of LiCl in water XLiCl = 0.0800

Mol of water in kg = 55.55 mole

Find:

Molality

Computation:

mole fraction = mol LiCl / (mol water + mol LiCl)

0.0800 = mol LiCl / (55.55 mol + mol LiCl)

0.0800 mol LiCl + 4.444 mol = mol LiCl

mol LiCl - 0.0800 mol LiCl = 4.444 mol

0.92 mol LiCl = 4.444 mol

mol LiCl = 4.83 m

Why can long chain fatty acids can form micelles in solutions with pH > 7 but are insoluble in pH < 5

Answers

Answer:

In basic conditions that is ( pH > 7 ), the equilibrium shifts towards right and produces a lot of (-ve) negatively charged fatty acids which are polar, In water, since they have long hydrophobic hydrocarbon part, this form micelles where the hydrocarbon part  remain inside the  sphere and -coo- group remain outside the sphere due to H-bonding interaction with water.

At ( pH < 5 ) I.e acidic conditions, the equilibrium shift to the left giving neutral molecules which can not have stronger H-bonding interaction .

So micelles cant form as they become insoluble.

What is the oxidizing agent in the redox reaction represented by the following cell notation? Ni(s) | Ni2+(aq) || Ag+(aq) | Ag(s)

Answers

Answer:

Silver.

Explanation:

Hello,

In this case, for the redox reaction:

[tex]Ni^0(s)+Ag^+(aq)\rightarrow Ni^{2+}+Ag^0(s)[/tex]

We can see the nickel is being oxidized as its oxidation state increases from 0 to 2+ whereas the oxidation state of silver decreases from +1 to 0, it means that the oxidizing agent is silver and the reducing agent is nickel.

Best regards.

The oxidizing agent in the redox reaction represented by the following cell notation is Silver.

Calculation of the oxidizing agent:

The redox reaction is

Ni(s) | Ni2+(aq) || Ag+(aq) | Ag(s)

here the nickel is being oxidized since its oxidation state rises from 0 to 2+ while on the other hand,  the oxidation state of silver is reduced from +1 to 0, it means that the oxidizing agent is silver and the reducing agent is nickel.

Learn more about reaction here: https://brainly.com/question/4241156

GIVING 100 POINTS PLEASE ANSWER SOON When ponds freeze, they freeze at the surface first before freezing at the bottom. Which property of water explains why this might happen? Density Adhesion High boiling point High specific heat

Answers

Answer:

[tex]\huge\boxed{Density}[/tex]

Explanation:

This is because of density. Since Ice is less dense than water, the ice even formed inside the pond then starts floating on the surface of water. Because of this density, Ice floats on water and thus the water freezes at the surface.

Answer:

Density

Explanation:

Water is less dense as a solid than as a liquid, so as ponds freeze, the ice floats at the top and the pond freezes from the top-down.

In the Lewis structure of AB4 where B is more electronegative than A. Both are main group elements where A has 8 valence electrons and each B has 7 valence electrons.

Required:
a. What is the total number of valence electrons?
b. How many lone pairs are in the molecule?

Answers

Answer:

1. 36

2. Two

Explanation:

The Lewis structure shows the valence electrons present in a compound. Usually the valence electrons are shown as dot structures around the symbol of the elements involved in the compound.

For a compound AB4 where B is more electronegative than A and A has 8 electrons in its valence shell, there will be thirty six valence electrons on the outermost shell of the molecule.

There are six electron pair domains present in the molecule, four bond pairs and two lone pairs. The molecule is in a square planar geometry.

Answer: a- 36 valence electrons

b- 14 lone pairs

Explanation:

Valence is equal to A + 4B = 8 + 4(7)

With 4 bonds between A and the 4 B, that is 36 valence minus 8 electrons in those pairs = 28. 28 is 14 lone pairs.

A sample of carbon dioxide gas has a density of g/L at a pressure of 0.889 atm and a temperature of 55.0 °C. Assume ideal behavior,occupies a volume of 686 mL. If the gas is heated at constant pressure until its volume is 913 mL, the temperature of the gas sample will be:_______ ? °C.

Answers

Answer:

163.5 °C

Explanation:

The following data were obtained from the question:

Initial volume (V1) = 686 mL.

Initial temperature (T1) = 55 °C.

Final volume (V2) = 913 mL

Initial pressure (P1) = final pressure (P2) = 0.889 atm

Final temperature (T2) =.?

Next, we shall convert celsius temperature to Kelvin temperature.

This can be done as shown below:

Temperature (K) = Temperature (°C) + 273

T(K) = T (°C) + 273

Initial temperature (T1) = 55 °C.

Initial temperature (T1) = 55 °C + 273

Initial temperature (T1) = 328 K

Next, we shall determine the new temperature of the gas.

Since the pressure is constant, we shall determine the new temperature as follow:

V1/T1 = V2 /T2

Initial volume (V1) = 686 mL.

Final volume (V2) = 913 mL

Initial temperature (T1) = 328 K

Final temperature (T2) =.?

V1/T1 = V2 /T2

686/328 = 913/T2

Cross multiply

686 x T2 = 328 x 913

Divide both side by 686

T2 = (328 x 913)/686

T2 = 436.5 K

Finally, we shall convert Kelvin temperature to celsius temperature.

This can be done as shown below:

Temperature (°C) = Temperature (K) – 273

T (°C) = T(K) – 273

T(K) = 436.5 K

T (°C) = 436.5 – 273

T (°C) = 163.5 °C

Therefore, the temperature of the gas sample is 163.5 °C.

When the nuclide carbon-14 undergoes beta decay: The name of the product nuclide is . The symbol for the product nuclide is

Answers

Answer:

Explanation:

The equation for the decay is given as;

¹⁴₆C  --> X + ⁰₋₁e

For conservation of matter, the mass number and atomic number has to be the same in both the reactant and product side f he equation;

Mass number;

14 = x + 0

x = 14

Atomic Number;

6 = x + (-1)

x = 6 + 1 =7

¹⁴₆C  --> ¹⁴₇N + ⁰₋₁e

The name of the product nuclide with atomic number of 7 is Nitrogen. The symbol is; ¹⁴₇N

A chemist prepares a solution of silver(I) nitrate(AgNO3) by measuring out 269. mu mol of silver(I) nitrate into a 300. mL volumetric flask and filling the flask to the mark with water. Calculate the concentration in mmol/L of the chemist's silver(I) nitrate solution.

Answers

Answer:

concentration   in    mmol/L = 8.97 × 10⁻¹ mmol/L

Explanation:

Given that:

the number of moles of  silver(I) nitrate(AgNO3) the chemist used in preparing a solution = 269 mmol = 269 × 10⁻³ mmol

The volume of the volumetric flask = 300 mL  = 300 × 10⁻³ L

In order to calculate the concentration in mmol/L of the chemist's silver(I) nitrate (AgNO3) solution , we used the formula which can be expressed as;

[tex]concentration \ in \ mmol/L = \dfrac{ number \ of \ mmol}{vol. \ of \ the \ solution}[/tex]

[tex]concentration \ in \ mmol/L = \dfrac{ 269 * 10^{-3 } \ mmol }{300 * 10^{-3} \ L }[/tex]

concentration   in    mmol/L = 0.8966   mmol/L

concentration   in    mmol/L = 8.97 × 10⁻¹ mmol/L

What are some geographic features that could be found in the hydrosphere?

Answers

Lakes, oceans, glaciers, clouds, etc. It categorizes all forms of water on earth.

hydro = water

Answer:

Lakes, streams, ground water, polar ice caps, glaciers, water vapor, and rivers!

Explanation:

The hydrosphere is made up of all the water on Earth. So anything that is water, like oceans, can be found in the hydrosphere:)

What is advertising used for? Check all that apply. influencing consumer tastes tracking product popularity increasing product awareness promoting company branding gathering data about potential consumers

Answers

Answer:

influencing consumer tastes

increasing product awareness

promoting company branding

Explanation:

Advertising is basically a form of communication using creative ideas and communicating benefits of the products. Advertising plays a very crucial role in product business and some of the important uses of advertising are as follows:

Creative advertisements, influence customers or consumers to buy the product.Advertisings involve information regarding the product and so increases product awareness.Advertising on social media platforms, TVs, radio and newspapers, promotes company branding.

Hence, the correct options are:

influencing consumer tastesincreasing product awarenesspromoting company branding

Answer:

1,3,4

Explanation:

I took the test

Other Questions
Davids family is driving from New York to Florida. They know the distance they will travel is about 1100 miles . If a map has a scale of 1 in = 80 mi about how far will the trip be on the map ? If you told a policeman about a car traveling 44.704 m/s (100 mph) that was traveling in an eastward direction, you would be describing the car's ___. What decimal number does point A on the number line below represent? A vertical number line is shown from negative 2.00 to 0 to positive 2.00.There are tick marks to show increments of 1 over 4. Only the whole numbers are labeled. Point A is plotted at the third tick mark below negative 1.00. 0.25 0.25 1.75 1.75 I NEED this answered within the next 30 minutes! Please it is simple. There is an error in this. What is it? What type of function is graphed in this figure?Question 20 options:A)Continuous non-linearB)Discrete linearC)Discrete non-linearD)Continuous linear ind the missing length. The triangles are similar. similar 16 A. 27 B. 24 C. 16 D. 21 Protestant values such as asceticism and entrepreneurship as a result of the belief that success on earth could lead to salvation, and a fervent individualism due to the belief that only individuals could be saved lead, in the right conditions, to the rise of capitalism. Who made this argument Literary Text: from The Devil's Dictionary, Ambrose BierceRead these entries from The Devil's Dictionary by Ambrose Bierce.Then, answer the question(s).Which statement best describes Bierce's tone and purpose?O Bierce uses an angry tone to condemn the sins of humanity.OBBierce uses a cynical tone to ridicule human behavior andsocietyO.Bierce uses a lighthearted tone to educate humanity in agentle way.DBierce uses a reprimanding tone to encourage humanbeings to improveABSURDITY n. A statement or belief manifestly inconsistentwith one's own opinion.ACADEME n. An ancient school where morality andphilosophy were taught.ACADEMY n. [from ACADEME] A modern school wherefootball is taughtBORE n. A person who talks when you wish him to listen.CABBAGE n. A familiar kitchen-garden vegetable about aslarge and wise as a man's head. [The cabbage is so calledfrom Cabagius, a prince who on ascending the throne issued adecree appointing a High Council of Empire consisting of themembers of his predecessor's Ministry and the cabbages in theroyal garden. When any of his Majesty's measures of statepolicy miscarried conspicuously it was gravely announced thatseveral members of the High Council had been beheaded, andhis murmuring subjects were appeased.] Given the linear correlation coefficient r and the sample size n, determine the critical values of r and use your finding to state whether or not the given r represents a significant linear correlation. Use a significance level of 0.05. r=0.767, n=25 Emma changed 500 into rand before going on holiday to South Africa.The rate of exchange at the time was 1 = 10.4 rand.Emma spent 4000 rand on holiday. When she got home, she changed her leftover rand into pounds.The exchange rate was now 1 = 9.8 rand. How much money did she get back in pounds? Journalize the following sales transactions for Salem Sportswear. Explanations are not required. Aug. 1 Salem sold $69,000 of women's sportswear on account, credit terms of 3 / 10, n / 60. Cost of goods is $38,000. 5 Salem received a $3,500 sales return on damaged goods from the customer. Cost of goods damaged is $1 ,750. 10 Salem receives payment from the customer on the amount due, less the return and discount.Journalize the sales transactions.Aug 1 : Salem sold $69,000 of women's sportswear on account, credit terms of 3 / 10, n / 60. Cost of goods is S38,000. Begin by preparing the entry to journalize the sale portion of the transaction. Prepare the journal entry to record Jevonte Companys issuance of 35,000 shares of its common stock assuming the shares have a: $3 par value and sell for $22 cash per share. $3 stated value and sell for $22 cash per share. The block moves up an incline with constant speed. What is the total work WtotalWtotalW_total done on the block by all forces as the block moves a distance LLL Miller Fruit wants to expand and needs $1.6 million to do so. Currently, the firm has 465,000 shares of stock outstanding at a market price per share of $32.50. The firm decided on a rights offering with one right granted for each share of outstanding stock. The subscription price is $28 a share. How many rights are needed to purchase one new share of stock in this offering?Miller Fruit wants to expand and needs $1.6 million to do so. Currently, the firm has 465,000 shares of stock outstanding at a market price per share of $32.50. The firm decided on a rights offering with one right granted for each share of outstanding stock. The subscription price is $28 a share. How many rights are needed to purchase one new share of stock in this offering? Perform the operation. (3x^2+4)-(-5x^2+4x-1) The magnetic field of a plane-polarized electromagnetic wave moving in the z-direction is given by in SI units. What is the frequency of the wave group the like term together Facial Cosmetics provides plastic surgery primarily to hide the appearance of unwanted scars and other blemishes. During 2021, the company provides services of $402,000 on account. Of this amount, $52,000 remains uncollected at the end of the year. An aging schedule as of December 31, 2021, is provided below. Age Group Amount Estimated Percent Receivable Uncollectible Not yet due $ 32,000 4 % 0-30 days past due 10,200 6 % 3160 days past due 7,200 12 % More than 60 days past due 2,600 30 % Total $ 52,000 Required: 1. Calculate the allowance for uncollectible accounts. 2. Record the December 31, 2021, adjustment, assuming the balance of Allowance for Uncollectible Accounts before adjustment is $400 (debit). 3. On April 3, 2022, a customers account balance of $500 is written off as uncollectible. Record the write-off. 4. On July 17, 2022, the customer whose account was written off in requirement 3 unexpectedly pays $100 of the amount but does not expect to pay any additional amounts. Record the cash collection. A scientist observes that the electrical resistance of a superconducting material drops to zero when the material is cooled to very low temperatures. Which of the following statements best describes what the scientist is observing?The scientist is observing the electrical power of a superconductor.The scientist is observing the temperature of a superconductor.The scientist is observing an intensive property of a superconductor.The scientist is observing an extensive property of a superconductor Use the information provided to determine a 95% confidence interval for the population variance. A researcher was interested in the variability in service time (in hours) spent by mechanics fixing the same automotive problem. A random sample was taken resulting in a sample of size 20 from a substantial file of reported experience. The summary statistics are as follows: n = 20, sample mean = 13.8 hours, sample standard deviation = 3.9 hours. Assume service time follows a normal distribution. Round to two decimal places.