Answer:
0.016 M
Explanation:
Molarity refers to the molar concentration of a solution and it can be calculated using the formula below:
Molarity (M) = number of moles (n) ÷ volume (V)
According to this question, the mass of KCl was given to be 0.72 grams and the volume of water as 600 mL.
Using mole = mass/molar mass to convert mass of KCl to moles
Molar mass of KCl = 39 + 35.5 = 74.5g/mol
mole = 0.72g ÷ 74.5g/mol
mole = 0.00966mol
Volume of water = 600mL = 600/1000 = 0.600L
Molarity, M = 0.00966 ÷ 0.600
Molarity of KCl solution = 0.016 M
A sample of a gas at 15°C and 2.50 atm pressure has a volume of 4.5 L. The pressure is lowered to 0.85 atm and the volume decreases to 2.5 L. What is the final temperature of the gas in K.
[tex]P_{1} = \text{2.50 atm}[/tex]
[tex]T_{1} = 15^{\circ}\text{C + 273 = 288 K}[/tex]
[tex]V_{1} = \text{4.5 L}[/tex]
[tex]P_{2} = \text{0.85 atm}[/tex]
[tex]V_{2} = \text{2.5 L}[/tex]
Unknown:[tex]T_{2}[/tex]
Solution:[tex]\dfrac{P_{1}V_{1}}{T_{1}} = \dfrac{P_{2}V_{2}}{T_{2}}[/tex]
[tex]T_{2} = T_{1} \times \dfrac{P_{2}}{P_{1}} \times \dfrac{V_{2}}{V_{1}}[/tex]
[tex]T_{2} = \text{288 K} \times \dfrac{\text{0.85 atm}}{\text{2.50 atm}} \times \dfrac{\text{2.5 L}}{\text{4.5 L}}[/tex]
[tex]\boxed{T_{2} = \text{54.4 K}}[/tex]
[tex]\\[/tex]
#ILoveChemistry
#ILoveYouShaina
A worker gets paid 11.33 $/hour. The worker works on average 39.7 hours/week for 48 weeks per year. How much does the worker make in 1.7 years?
Answer:
36704 $
Explanation:
First we calculate how much the worker gets paid in one week:
11.33 $/hour * 39.7 hour/week = 449.80 $/weekThen we calculate how many weeks does the worker work in 1.7 years:
48 week/year * 1.7 years = 81.6 weeksFinally we calculate how much does the worker make in 1.7 years:
449.80 $/week * 81.6 weeks = 36704 $aluminum chloride and bubbles of hydrogen gas are produced when metallic aluminum is placed in hydrochloride acid. what is a balanced equation for this reaction?
Answer:
AlCl3 + HCl ===> AlCl4 +H-
It took 2.30 minutes using a current of 3.00 A to plate out all the copper from 0.300 L of a solution containing Cu2 . What was the original concentration of Cu2
Answer:
7.16 × 10⁻³ M
Explanation:
Let's consider the reduction reaction of copper during the electroplating.
Cu²⁺(aq) + 2 e⁻ ⇒ Cu(s)
We can calculate the moles of Cu²⁺ present in the solution using the following relations.
1 A = 1 C/s.1 min = 60 s.1 mole of electrons has a charge of 96486 C (Faraday's constant).1 mole of Cu²⁺ is reduced when 2 moles of electrons are gained.The moles of Cu²⁺ reduced are:
[tex]2.30 min \times \frac{60s}{1min} \times \frac{3.00C}{s} \times \frac{1mole^{-} }{96486C} \times \frac{1molCu^{2+} }{2mole^{-} } = 2.15 \times 10^{-3} molCu^{2+}[/tex]
[tex]2.15 \times 10^{-3} moles[/tex] of Cu²⁺ are in 0.300 L of solution.
[Cu²⁺] = 2.15 × 10⁻³ mol/0.300 L = 7.16 × 10⁻³ M
what flora eat? pliz tell me someone
Answer:
flora eat food
Explanation:
because that what every living thing eats to grow.
Answer:
sugar??
Explanation:
plants photosynthesise to make their own food (mainly glucose) to be transported around the plant
Waves are generated when energy passes through causing them to move matter through ____ ?
Answer:
sending heat waves and vibrations
Which two properties are explained by the pool-of-shared-electrons model for metals?
A. low vapor pressure, high melting point
B. malleability, conductivity
C. high melting point, conductivity
D. low vapor pressure, malleability
Answer:
Actually the answer is B Malleability, conductivity
Explanation:
QUESTION 3 (a) Ammonium sulphate, (NH),50, is a soluble salt and it is used in agriculture as fertiliser. 5 g of ammonium sulphate is dissolved in 1 litre of water to produce ammonium sulphate solution. (Relative atomie mass: H = 1, N = 14,0 = 16, )
Calculate
(1) the number of inoles of dissolved ammonium sulphate
(ii) the number of molecules present in the ammonium sulphate solution.
(iii) the number of positive ions present in the ammonium sulphate solution
(iv) the number of negative ions present in the ammonium sulphate solution
(v) the total number of ions present in the ammonium sulphate solution
Answer:
The equation: (NH₄)₂SO₄ = 2NH4(+) + SO4(-2)
The number of moles = 5 g / 132.14 g/mol = 0.038 mol
The number of molecules = 0.038 X 6.022x10^23 = 2.29x10^23
the number of positive ions present in the ammonium sulphate solution:
2 positive ions for every 1 molecule of (NH₄)₂SO₄
so 2 x 2.29x10^23 = 4.58x10^23
the number of negative ions present in the ammonium sulphate solution
1 negative ion for every 1 molecule of (NH₄)₂SO₄
so 1 x 2.29x10^23 = 2.29x10^23
the total number of ions present in the ammonium sulphate solution
4.58x10^23 + 2.29x10^23 = 6.87x10^23
Who was the first person to suggest the existence of atoms?
Answer:
Democritus first introduced the idea of the atom almost 2500 years ago.
Answer:
B. Democritus
Explanation:
Kristy finds the mass of an object to be 20 grams and the volume to be 10 mL. What is the density of the object? (don't send me links, just give a straight answer)
Which is most likely the first step in a basic food chain?
1. The snake obtain energy by eating the mouse
2. Plants make energy-rich food using sunlight
3. The hawk obtains energy by eating the snake
4. The sun emits energy.
Answer:
4
Explanation:
Question 8 (5 points)
(08.02 MC)
A 10 M concentrated stock solution of NaCl was used to prepare 5 liters of diluted 1 M solution. Which of the following statements is true about
the
process used to achieve this required dilution? (5 points)
O a
The volume of stock solution used was less than 0.4 liters.
Oь
The volume of stock solution used was more than 5 liters.
Ос
The volume of the solvent used was less than 0.4 liters.
Od
The volume of the solvent used was less than 5 liters.
Answer:
d . The volume of the solvent used was less than 5 liters.
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to calculate the volume of the stock (initial) solution by using the following equation:
[tex]M_1V_1=M_2V_2[/tex]
Thus, we solve for, V1, which stands for the aforementioned volume of stock solution:
[tex]V_1=\frac{M_2V_2}{M_1}[/tex]
Then, we plug in to obtain:
[tex]V_1=\frac{5L*1M}{10M}\\\\V_1=0.5L[/tex]
Now, since the final volume was 5 L, we can infer that the volume of solvent is 4.5 L and that of the stock solution 0.5 L for a total of 5 L of diluted solution; therefore, the correct reasoning is d . The volume of the solvent used was less than 5 liters.
Regards!
Answer:
The volume of the solvent is less than 5
Explanation:
A company manufacturing KMnO4 wants to obtain the highest yield possible. Two of their research scientists are working on a technique to increase the yield.
Both scientists started with 50.0 g of manganese oxide (MnO2).
What is the theoretical yield of potassium permanganate when starting with this 50.0 g MnO2?
The equation for the production of potassium permanganate is as follows:
2 MnO2 + 2 KOH + O2 → 2 KMnO4 + H2
You must show all work to receive full credit.
Answer:
[tex]m_{KMnO_4}=90.9gKMnO_4[/tex]
Explanation:
Hello there!
In this case, according to the given chemical equation for the reaction for the production of potassium permanganate, we can see a 2:2 mole ratio of this product to the starting manganese (II) oxide, which means, we can calculate the theoretical yield of the former via stoichiometry:
[tex]m_{KMnO_4}=50.0gMnO_2*\frac{1molMnO_2}{86.94gMnO_2}*\frac{2molKMnO_4}{2molMnO_2} *\frac{158.034gKMnO_4}{1molKMnO_4} \\\\m_{KMnO_4}=90.9gKMnO_4[/tex]
Regards!
The average molecular speed in a sample of Ar gas at a certain temperature is 213 m/s. The average molecular speed in a sample of Ne gas is ______ m/s at the same temperature.
Answer:
300m/s is the average molecular speed of Ne
Explanation:
Based on Graham's law, the ratio of speed of two gases under constant temperature is equal to the square root of the inverse of their molar masses. The equation is:
v1 / v2 = √m2 / √m1
Where v is the speed of the gas and m the molar mass of the gas
Assuming gas 1 is Argon and gas 2 is Neon:
v1 = 213m/s
v2 = ?
m2 = 20.18g/mol
m1 = 39.948g/mol
213m/s / v2 = √20.18g/mol / √39.948g/mol
v2 = 213m/s / 0.71074
v2 = 300m/s is the average molecular speed of Ne
Describe the three freezing points. Is there a relationship between the amount of solute in the solution and the freezing temperature
Answer:
The three freezing points will all be slightly different. It is given that a water solution has a freezing point of zero degrees Celsius, so water would have a freezing temperature below that. Salt will lower the freezing point, the more that is added.
Explanation:
How much energy is produced when 13.1 g of tin reacts with 2.715 g of N2 ?
I.
3 Sn + 2 N2-----------Sn3N4 + 632 KJ
Hint change grams to moles first.
1 mole Sn= 119g
1 mole N2= 28 g
Answer:
23.2 kJ of energy are released by the reaction.
Explanation:
Hello there!
In this case, according to the given information, it turns out firstly necessary for us to calculate the moles of both tin and nitrogen and the produced moles of Sn3N4 product by each reactant as shown below:
[tex]13.1gSn*\frac{1molSn}{119gSn} *\frac{1molSn_3N_4}{3molSn} =0.0367molSn_3N_4\\\\2.715gN_2*\frac{1molN_2}{28gN_2} *\frac{1molSn_3N_4}{2molN_2} =0.0485molSn_3N_4[/tex]
Thus, since 13.1 grams of tin produce the fewest moles of Sn3N4 product, we infer tin is the limiting reactant, and the correct produced energy, due to this reaction is:
[tex]E=632\frac{kJ}{mol\ rxn}*\frac{1mol\ rxn}{1molSn_3N_4}*0.0367mol Sn_3N_4\\\\E=23.2kJ[/tex]
Regards!
For the balanced chemical reaction
>
C4H2OH + 602 > 4CO2 + 5H20
if you want to make 100 molecules of CO2, how many molecules of O2 will you need? Answer with a number only.
ITS
Answer:
150
Explanation:
C₄H₂OH + 6O2 → 4CO2 + 5H₂OWe can find the equivalent number of O₂ molecules for 100 molecules of CO₂ using a conversion factor containing the stoichiometric coefficients of the balanced reaction, as follows:
100 molecules CO₂ * [tex]\frac{6moleculesO_2}{4moleculesCO_2}[/tex] = 150 molecules O₂150 molecules of O₂ would produce 100 molecules of CO₂.
Which of the following natural hazards occur for a long period of time?
tornado
earthquake
drought
thunderstorm
Answer:
drought
Explanation:
droughts are long periods without water
f(x) = -x2+x+6
x
-2
a
-1
4
0
b
1
6
2
c с
do
11 11 11
Cross primary components of vascular tissue are the xylem and phloem. These two tissues transport fluid and nutrients internally. There are also two meristems associated with vascular tissue: the vascular cambium and the cork cambium. All the vascular tissues within a particular plant together constitute the vascular tissue system of that plant.
b. The following reaction takes place in a basic solution. (7 points)
MnO4–(aq) + NO2–(aq) MnO2(s) + NO3–(aq)
The half-reactions (balanced only for atoms) are the following:
MnO4– + 2H2O MnO2 + 4OH–
NO2– + 2OH– NO3– + H2O
Use the following steps to finish balancing the equation.
i. Balance each half-reaction for charge. (2 points)
ii. Multiply each half-reaction by the correct number in order to balance charges for the two half-reactions. (2 points)
iii. Add the equations and simplify to get a balanced equation. (2 points)
iv. How can you tell from this equation that the reaction occurred in a basic solution? (1 point)
Answer: The final equation has hydroxide ions which indicate that the reaction has occurred in a basic medium.
Explanation:
Redox reaction is defined as the reaction in which oxidation and reduction take place simultaneously.
The oxidation reaction is defined as the reaction in which a chemical species loses electrons in a chemical reaction. It occurs when the oxidation number of a species increases.
A reduction reaction is defined as the reaction in which a chemical species gains electrons in a chemical reaction. It occurs when the oxidation number of a species decreases.
The given redox reaction follows:
[tex]MnO_4^-(aq)+NO_2^-(aq)\rightarrow MnO_2(s)+NO_3^-(aq)[/tex]
To balance the given redox reaction in basic medium, there are few steps to be followed:
Writing the given oxidation and reduction half-reactions for the given equation with the correct number of electronsOxidation half-reaction: [tex]NO_2^-+2OH^-\rightarrow NO_3^-+H_2O+2e^-[/tex]
Reduction half-reaction: [tex]MnO_4^-+2H_2O+3e^-\rightarrow MnO_2+4OH^-[/tex]
Multiply each half-reaction by the correct number in order to balance charges for the two half-reactionsOxidation half-reaction: [tex]NO_2^-+2OH^-\rightarrow NO_3^-+H_2O+2e^-[/tex] ( × 3)
Reduction half-reaction: [tex]MnO_4^-+2H_2O+3e^-\rightarrow MnO_2+4OH^-[/tex] ( × 2)
The half-reactions now become:
Oxidation half-reaction: [tex]3NO_2^-+6OH^-\rightarrow 3NO_3^-+3H_2O+6e^-[/tex]
Reduction half-reaction: [tex]2MnO_4^-+4H_2O+3e^-\rightarrow 2MnO_2+8OH^-[/tex]
Add the equations and simplify to get a balanced equationOverall redox reaction: [tex]3NO_2^-+2MnO_4^-+H_2O\rightarrow 3NO_3^-+2MnO_2+2OH^-[/tex]
As we can see that in the overall redox reaction, hydroxide ions are released in the solution. Thus, making it a basic solution
Guys i need a long inforation about....
"Formation of colloids"
Please and thank you
Answer:
Colloids
There are two basic methods of forming a colloid: reduction of larger particles to colloidal size, and condensation of smaller particles (e.g., molecules) into colloidal particles. Some substances (e.g., gelatin or glue) are easily dispersed (in the proper solvent) to form a colloid; this spontaneous dispersion is called peptization. A metal can be dispersed by evaporating it in an electric arc; if the electrodes are immersed in water, colloidal particles of the metal form as the metal vapor cools. A solid (e.g., paint pigment) can be reduced to colloidal particles in a colloid mill, a mechanical device that uses a shearing force to break apart the larger particles. An emulsion is often prepared by homogenization, usually with the addition of an emulsifying agent. The above methods involve breaking down a larger substance into colloidal particles. Condensation of smaller particles to form a colloid usually involves chemical reactions—typically displacement, hydrolysis, or oxidation and reduction.
The most intense line in the emission spectrum for sodium appears at a wavelength of 589 nm. What color would you expect to observe when a solution that contains sodium ions is heated strongly in the flame of a Bunsen burner
Answer:
The most intense line in the emission spectrum for sodium appears at a wavelength of 589 nm.
What color would you expect to observe when a solution that contains sodium ions is heated strongly in the flame of a Bunsen burner?
Explanation:
Put a clean wire loop in a solid sample of the compound containing sodium ions, then keep it on the blue flame of the Bunsen burner.
The color of sodium ions in the Bunsen burner shows charactrestic yellow color.
Why is specific activity used as a measurement of enzyme purity, but the turnover number cannot be used for this purpose?
Answer:
See explanation
Explanation:
Specific activity of an enzyme is defined as a measure of the rate of reaction between enzyme and substrate.
In the study of enzyme kinetics, specific activity is particularly regarded to be the amount of substrate converted by the enzyme per milligram of protein per unit of time. It is thus a reliable measure of enzyme activity per milligram of total protein.
On the other hand, the turnover number is defined as a measure of the number of conversions achieved by a substrate molecule in one second at a particular active site depending on the specific enzyme concentration.
Since specific activityof the enzyme is the ratio of the enzyme activity to enzyme concentration, then specific activity can be used as a measurement of enzyme purity.
PLSSS HELP MEEEEEEEE
It takes 5 seconds for a wave with a wavelength of 0.4 m to travel past you.
What is the frequency of the wave?
A. 2.0 Hz
B. 0.2 Hz
C. 5 Hz
D. 2.5 Hz
Answer:
A
Explanation:
frequency is the product of time and wave length
Answer:
(B) 0.2Hz
Explanation:
took the test and it for sure was not 2.0Hz
A 3.06 gram sample of an unknown hydrocarbon with empirical formula CH2O was found to contain 0.0170 moles of the substance. What are the molecular mass and molecular formula, respectively, of the compound
Answer:
180 amu
C₆H₁₂O₆
Explanation:
Step 1: Determine the molecular mass of the compound
The sample has a mass (m) of 3.06 g and it contains (n) 0.0170 moles. The molar mass M is:
M = m/n = 3.06/0.0170 mol = 180 g/mol
Then, the molecular mass is 180 amu.
Step 2: Determine the molar mass of the empirical formula.
M(CH₂O) = 1 × M(C) + 2 × M(H) + 1 × M(O)
M(CH₂O) = 1 × 12 g/mol + 2 × 1 g/mol + 1 × 16 g/mol = 30 g/mol
Step 3: Determine the molecular formula
First, we will determine "n" according to the following expression.
n = molar mass molecular formula / molar mass empirical formula
n = 180 g/mol / 30 g/mol = 6
The molecular formula is:
n × CH₂O = 6 × CH₂O = C₆H₁₂O₆
In this lab, you will be making solutions of potassium permanganate (KMnO4), which has a formula weight of 158.04 g/mole. Remember to show your calculations and include tne Correct unnits in your answers
a) How many grams of KMnO4 would you need to make 1 L of a 2M solution?
b) How many grams of KMnO4 would you need to make 350 mL of a 0.75 M solution?
c) How many grams of KMnO4 would you need to make 80 mL of a 0.01 M solution?
Answer:
A. Mass of KMnO₄ = 316.08 g
B. Mass of KMnO₄ = 41.49 g
C. Mass of KMnO₄ = 0.13 g.
Explanation:
A. Determination of the mass of KMnO₄
We'll begin by determining the number of mole of KMnO₄ in the solution. This can be obtained as follow:
Volume = 1 L
Molarity = 2 M
Mole of KMnO₄ =?
Mole = Molarity × Volume
Mole of KMnO₄ = 2 × 1
Mole of KMnO₄ = 2 moles
Finally, we shall determine the mass of KMnO₄. This can be obtained as follow:
Mole of KMnO₄ = 2 moles
Molar mass of KMnO₄ = 158.04 g/mole
Mass of KMnO₄ =?
Mass = mole × molar mass
Mass of KMnO₄ = 2 × 158.04
Mass of KMnO₄ = 316.08 g
B. Determination of the mass of KMnO₄
We'll begin by determining the number of mole of KMnO₄ in the solution. This can be obtained as follow:
Volume = 350 mL = 350/1000 = 0.35 L
Molarity = 0.75 M
Mole of KMnO₄ =?
Mole = Molarity × Volume
Mole of KMnO₄ = 0.75 × 0.35
Mole of KMnO₄ = 0.2625 mole
Finally, we shall determine the mass of KMnO₄. This can be obtained as follow:
Mole of KMnO₄ = 0.2625 mole
Molar mass of KMnO₄ = 158.04 g/mole
Mass of KMnO₄ =?
Mass = mole × molar mass
Mass of KMnO₄ = 0.2625 × 158.04
Mass of KMnO₄ = 41.49 g
C. Determination of the mass of KMnO₄
We'll begin by determining the number of mole of KMnO₄ in the solution. This can be obtained as follow:
Volume = 80 mL = 80/1000 = 0.08 L
Molarity = 0.01 M
Mole of KMnO₄ =?
Mole = Molarity × Volume
Mole of KMnO₄ = 0.01 × 0.08
Mole of KMnO₄ = 0.0008 mole
Finally, we shall determine the mass of KMnO₄. This can be obtained as follow:
Mole of KMnO₄ = 0.0008 mole
Molar mass of KMnO₄ = 158.04 g/mole
Mass of KMnO₄ =?
Mass = mole × molar mass
Mass of KMnO₄ = 0.0008 × 158.04
Mass of KMnO₄ = 0.13 g
The student adds 0.0010 mol of NaOH(s) to solution Y, and adds 0.0010 mol of NaOH(s) to solution Z. Assume that the volume of each solution does not change when the NaOH(s) is added. The pH of solution Y changes much more than the pH of solution Z changes. Explain this observation.
Answer:
The answer is in the explanation.
Explanation:
A buffer is defined as the aqueous mixture of a weak acid and its conjugate base or vice versa. Buffers are able to avoid the pH change of a solution when strong acid or bases are added (As NaOH).
Based on the experiment, it is possible that the solution Z was a buffer and Y another kind of solution. For this reson, pH of the solution Y changes much more than the pH of solution Z changes despite the amount of NaOH added is the same in both solutions.
Describe the buffer capacity of the acetic acid buffer solution in relation to the addition of both concentrated and dilute acids and bases. Reference the results in Data Tables 1,2,3, and 4 in your answer.
Answer:
The more concentrated acetic acid buffer has a better buffer capacity because requires more moles of acid or base to change the pH than a more diluted acetic acid buffer.
Explanation:
Buffer capacity is defined as the moles of an acid or base that are needed to change the pH of a buffer in 1 unit.
A more concentrated solution of acetic buffer contains more moles of the acid per liter of solution. A solution that contains more moles of the acetic ion or the acetic acid requires more moles of base or acid to change the pH, that means:
The more concentrated acetic acid buffer has a better buffer capacity because requires more moles of acid or base to change the pH than a more diluted acetic acid buffer.
Why all mushrooms cannot be eaten?
Explanation:
The toxins present are secondary metabolites produced by the fungus. Mushroom poisoning is usually the result of ingestion of wild mushrooms after misidentification of a toxic mushroom as an edible species. ... The safety of eating wild mushrooms may depend on methods of preparation for cooking.
(a) Describe the process by which Nitrogen is obtained from air on a large scale
The element nitrogen exists as a gas and is obtained from air on a large scale by fractional distillation of air.
What is an element?An element is defined as a substance which cannot be broken down further into any other substance. Each element is made up of its own type of atom. Due to this reason all elements are different from one another.
Elements can be classified as metals and non-metals. Metals are shiny and conduct electricity and are all solids at room temperature except mercury. Non-metals do not conduct electricity and are mostly gases at room temperature except carbon and sulfur.
The number of protons in the nucleus is the defining property of an element and is related to the atomic number.All atoms with same atomic number are atoms of same element.
Learn more about element,here:
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