Answer:
a. -7.44 °C
Explanation:
Hello there!
In this case, since the freezing point depression formula is:
[tex]\Delta T_f=-i*m*Kf[/tex]
Thus, since the Van't Hoff's factor is 2 for KCl as it ionizes in K⁺ and Cl⁻, the molarity is 2.0 m (2.0mol/1.0kg) and the freezing point depression constant is 1.86 °C/m, we calculate the freezing point depression as follows:
[tex]\Delta T_f=-2*2.0m*1.86\°C /m\\\\\Delta T_f=-7.44\°C[/tex]
Therefore, the answer is a. -7.44 °C.
Regards!
Please help! Thanks in advance!
Where is ur question ⁉️
In the picture this is my last question pls.
Answer:
Chromosomes and I think its too many
Explanation:
Which of these is NOT a characteristics of minerals?
A) organic
B) inorganic
C) crystalline structure
D) definite chemical composition
Answer:a) organic
Explanation:
Question on the image
Answer: The mass of carbon dioxide required is 308 g
Explanation:
The number of moles is defined as the ratio of the mass of a substance to its molar mass.
The equation used is:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)
Given mass of octane = 100.0 g
Molar mass of octane = 114.23 g/mol
Putting values in equation 1, we get:
[tex]\text{Moles of octane}=\frac{100.0g}{114.23g/mol}=0.875mol[/tex]
For the given chemical reaction:
[tex]2C_8H_{18}+25O_2\rightarrow 16CO_2+18H_2O[/tex]
By the stoichiometry of the reaction:
2 moles of octane produces 16 moles of carbon dioxide
So, 0.875 moles of octane will produce = [tex]\frac{16}{2}\times 0.875=7mol[/tex] of carbon dioxide
Molar mass of carbon dioxide = 44 g/mol
Plugging values in equation 1:
[tex]\text{Mass of carbon dioxide}=(7mol\times 44g/mol)=308g[/tex]
Hence, the mass of carbon dioxide required is 308 g
How many significant digits should be used to report the answer to each of the following calculations? (2.75518 + 9.01 + 3.3349) / (2.1)
Answer:
2
Explanation:
You write your answer with the same number of significant figures as the number with the smallest amount of figures, in this case, that number is 2.1 so your answer should be written with 2 significant figures.
The shielding of electrons gives rise to an effective nuclear charge, Zeff, which explains why boron is larger than oxygen. Estimate the approximate Zeff felt by a valence electron of boron and oxygen, respectively.
a. +5 and +8.
b. +3 and +6.
c. +5 and +6.
d. +3 and +8.
e. +1 and +4.
Answer:
b. +3 and +6.
Explanation:
Zeff = Z - S
The Z denotes the no of protons i.e. atomic number
S denotes the non-valence electrons
For boron,
the electronic configuration is 1s₂ 2s₂ 2p₄
Now
Z = 5, S = 2
So,
Zeff = 5-2
= +3
For O, the electronic configuration is 1s₂ 2s₂ 2p₄
So,
Z = 8, S = 2
= 8-2
= +6
Hence, the second option is correct
g a commercial product for treating injuries contains 35.0 g of MgSO4 in one bag and 250 mL of water in a seperate bag. When the bags are broken and their contents mixed, the temperature of the system changes. Calculate this temperature change
Answer:
he a real G
Explanation:
og tripple og
Look at pictures and help please
Answer: In order to increase the rate of reaction between hydrochloric acid and sugar increase the concentration of hydrochloric acid to 2 M because greater concentration results in more collision between the reactants.
Explanation:
More is the concentration of reactant molecules more will be the number of collisions between their molecules. As a result, more readily the products will be formed.
Hence, for the given reaction when concentration of HCl is increased then there will be increase in the number of collisions between reactants.
Thus, we can conclude that in order to increase the rate of reaction between hydrochloric acid and sugar increase the concentration of hydrochloric acid to 2 M because greater concentration results in more collision between the reactants.
sound waves? like what they do.
Answer:
A sound wave is the pattern of disturbance caused by the movement of energy traveling through a medium (such as air, water, or any other liquid or solid matter) as it propagates away from the source of the sound. The source is some object that causes a vibration, such as a ringing telephone, or a person's vocal chords.
HEY. HOPE THIS HELPS♡
HELPPP PLEASEEEEE
Name the following alkane molecule:
Answer:
5–bromo–9–chlorodecane
Explanation:
To name the compound given above, the following must be obtained:
1. The longest continuous carbon chain. This gives the parent name of the compound.
2. The substituent group attached to the compound.
3. Position of the substituent group.
4. Combine the above to obtain the name.
Now, we shall determine the name of the compound as follow:
1. The longest continuous carbon chain is 10. Thus, the parent name of the compound is decane.
2. The substituent groups attached to the compound are:
I. Bromine (Br) => Bromo
II. Chlorine (Cl) => Chloro
3. The position of the substituent groups are:
I. Br => carbon 5
II. Cl => carbon 9
NOTE: numbering is done alphabetically.
4. Therefore, the name of the compound is:
5–bromo–9–chlorodecane
Answer:
A.
Explanation:
I chose this answer and it was correct ♀️
Plss help me solve question 7
Thank you.
Answer:
4- ethyl- 6-methylocta- 1,2,5- triene
Explanation:
See attached. Please give me brainliest I worked hard. ;(
3. How many electrons are in the M shell?
Answer:
i believe the answer is D: 18
Explanation:
Answer:
18
M shell can actually hold 18 electron as you move higher atomic number
What was one idea Dalton taught about atoms?
Explanation:
All atoms of one type were identical in mass and properties.
A 1.375 g sample of mannitol, a sugar found in seaweed, is burned completely in oxygen to give 1.993 g of carbon dioxide and 0.9519 g of water. The empirical formula of mannitol is
Answer:
[tex]C_3H_7O_3[/tex]
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to infer that the empirical formula of mannitol contains carbon, hydrogen and oxygen, so that the first step is to calculate the moles of C and H contained in the CO2 and H2O, respectively, as the only sources of these two elements in the formula:
[tex]n_C=1.993gCO_2*\frac{1molCO_2}{44.01gCO_2}*\frac{1molC}{1molCO_2} =0.0453molC\\\\n_H=0.9519gH_2O*\frac{1molH_2O}{18.02gH_2O}*\frac{2molH}{1molH_2O} =0.106molH[/tex]
Next, we calculate the grams and moles of O by subtracting the mass of C and H from the mass of the sample:
[tex]m_O=1.375g-0.0453molC*\frac{12gC}{1molC}-0.106molH*\frac{1.01gH}{1molH}=0.724gO\\\\n_O=0.724gO*\frac{1molO}{16.0gO} =0.0453molO[/tex]
Finally, we divide the moles of C, H and O by 0.0453 as the fewest moles of both C and O to find the mole ratios in the formula:
[tex]C:\frac{0.0453mol}{0.0453mol} =1\\\\H:\frac{0.106mol}{0.0453mol} =2.34\\\\O:\frac{0.0453mol}{0.0453mol} =1[/tex]
To get:
[tex]CH_{2.34}O[/tex]
Which must be multiplied by 3 to get whole numbers for all the subscripts, and therefore obtain:
[tex]C_3H_7O_3[/tex]
Regards!
the mass of a single potassium atom is 6.50×10-23 grams. How many potassium atoms would there be in 114 milligrams of potassium?
Answer:LOL
42
Explanation:
The mass of a single potassium atom is 6.50×10⁻²³ grams potassium atoms would be in 114 milligrams of potassium 17.53 ×10⁻²³.
What is an atom?
An atom is the most diminutive form of any chemical compound that takes part in the chemical reaction to form any product and it is equal to the one mole which is 2.303 ×10²³ moles of the Avogadros number.
To calculate the number of atoms we have, 6.50×10⁻²³ grams of potassium and the value of one particle is 2.303 ×10²³ moles,
atoms = 6.50×10⁻²³ / 114 milligrams of potassium
atoms of potassium = 17.53 ×10⁻²³. atoms.
Therefore, 17.53 ×10⁻²³.atoms are present if the mass of a single potassium atom is 6.50×10⁻²³ grams potassium atoms would there be in 114 milligrams of potassium.
Learn more about atoms, here:
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Question 3 0 / 1 point How many grams of carbon atoms are present in a sample of C3H8 if there are 4.10 moles of hydrogen atoms in the sample
Answer:
18.45 g of C
Explanation:
This is a problem of rules of three:
1 mol of C₃H₈ contains 3 moles of C and 8 moles of H
If 8 moles of H are contained in 1 mol of propane
4.10 moles of H are contained in (4.1 . 1) /8 = 0.5125 moles
Now, If 1 mol of propane contains 3 moles of C
0.5125 moles of propane may contain (0.5125 . 3) / 1 = 1.5375 moles of C
Let's convert the moles to mass:
1.5375 mol . 12 g /mol = 18.45 g
Consider the reaction of Copper with Sulfur: Cu +S → Cus. Using the
below data, which of following is true?
A. Sulfur was the limiting reactant; 1.61 g of sulfur were reacted.
B. Copper was the limiting reactant; 1.32 g of sulfur were unreacted
C. Copper (II) sulfide was the limiting reactant; 4.78 g was formed.
D. There was no limiting reactant; both reactants remained in excess.
Answer:
B. Copper was the limiting reactant; 1.32 g of sulfur were unreacted
Explanation:
Cu + S → CuS
As there was no Cu left after the reaction was completed, Cu was not the reactant in excess but rather the limiting reactant.Copper (II) sulfide (CuS) cannot be the limiting reactant, because it is not a reactant but a product.With the two points above in mind, the only option left is B.
What is the solute and solvent in a solution of salt water
Answer:
The solute is salt and the solvent is water
Explain:
Because salt is a component the dissolves in the solvent
Electrons are in ___________ ___________ surrounding the nucleus.
Answer:
electron shells
Explanation:
Eletrons are on the outeermost part of the atom called electron shells.
information-
The chemical equation is Mg(s) + O2(g) → MgO(s)
for trial 1-
the mass of empty crucible with lid is- 26.680 g
the mass of Mg metal, crucible and lid is- 26.993 g
the mass of MgO, crucible and lid is- 27.194 g
for trial 2-
the mass of empty crucible with lid is- 26.682 g
the mass of Mg metal, crucible and lid is- 27.100 g
the mass of MgO, crucible and lid is- 27.194 g
------------------------------------------------------------------------------------------------
Questions-
1. Magnesium is the limiting reactant in this experiment. What is the theoretical yield of MgO for each trial?
2. what is the percent yield of MgO for the experiment for each trial?
3. what is the average percent yield of MgO for the two trials?
Answer:
So first thing to do in these types of problems is write out your chemical reaction and balance it:
Mg + O2 --> MgO
Then you need to start thinking about moles of Magnesium for moles of Magnesium Oxide. Based on the above equation 1 mole of Magnesium is needed to make one mole of Magnesium Oxide.
To get moles of magnesium you need to take the grams you started with (.418) and convert to moles by dividing by molecular weight of Mg (24.305), this gives you .0172 moles of Mg.
The theoretical yield would be the assumption that 100% of the magnesium will be converted into Magnesium Oxide, so you would get, based on the first equation, .0172 mol of MgO. Multiplying this by the molecular weight of MgO (24.305+16) gives us .693 g of MgO.
The percent yield is what you actually got in the experiment, and for this you subtract off the total mass from the crucible mass, or 27.374 - 26.687, which gives .66 g of MgO obtained.
Percent yield is acutal/theoretical, .66/.693, or 95.24%.
I'll let you do the same for the second trial, and average percent yield is just an average of the two trials percent yield.
Hope this helps.
What would I write in there? I’m confused
A sample of gas with an initial volume of 9.35 L at a pressure of 784 torr and a temperature of 295 K is compressed to a volume of 2.84 L and warmed to a temperature of 310 K. What is the final pressure of the gas in atmospheres (atm)?
a. 4.97 atm.
b. 0.113 atm.
c. 5.95 atm.
d. 7.03x10^3 atm.
Answer:
D
Explanation:
The decomposition of hydrogen peroxide was studied, and the following data were obtained at a particular temperature.Time (s) [H2O2] (mol/L)0 1.00120 ± 1 0.91300 ± 1 0.78600 ± 1 0.591200 ± 1 0.371800 ± 1 0.222400 ± 1 0.133000 ± 1 0.0823600 ± 1 0.050 Assuming that the rate= -delta [H2O2]/delta t determine the rate law, integrated rate law, and the value of the rate constant. Calculate [H2O2] at 4000. s after the start of the reaction.
Answer:
Explanation:
From the graphical diagram attached below; we can see the relationship between the concentration of [tex]H_2O_2[/tex] which declines exponentially in relation to the time and it obeys the equation: [tex]\mathtt{y = 0.9951 e^{-8\times 10^{-4}x}}[/tex]
This relates to the 1st order reaction rate, whereby:
The integrated rate law[tex]\mathtt{ [A] = [A]_o e^{-kt}}[/tex]
here:
[A] = reactant concentration at time (t)
[A]_o = initial concentration for the reactant
k = rate constant
As such, the order of the reaction is the first order
Rate constant [tex]\mathtt{k = 8\times 10^{-4} {s^{-1}}}[/tex]
Rate law [tex]\mathtt{= k[H_2O_2]}[/tex]
The integrated rate law [tex]\mathtt{[H_2O_2] = [H_2O_2]_oe^{-(8*10^{-4})t}}[/tex]
From the given table:
the initial concentration of [tex]H_2O_2[/tex] = 1.00 M
∴
We can determine the concentration of the reactant at 4000s by using the formula:
[tex]\mathtt{[H_2O_2] = [H_2O_2]_oe^{-8*10^{-4}(t)}}[/tex]
[tex]\mathtt{[H_2O_2] = (1.00\ M)*e^{-8*10^{-4}(4000)\ s}}[/tex]
[tex]\mathtt{[H_2O_2] =0.0407 \ M}[/tex]
Finally, at 4000s: the average rate is:
[tex]\mathtt{= (8*10^{-4} \ s^{-1})(4000 \ s) }\\ \\ \mathtt{ = 3.256 \times 10^{-5} \ M/s}[/tex]
A certain shade of blue has a frequency of 7.28×1014 Hz.
What is the energy of exactly one photon of this light? Planck's constant is ℎ=6.626×10−34 J⋅s.
Explanation:
the enerfy of of one photon of this light is 4.85x10^-19 J
E= 6.63 x 10^-34 J/S x 7.32 x10^14 S ^-1E= 4.85x10^-19 J
Help me ASAP PLS
What mass of glucose, C6H12O6, is needed to make 500.0 mL of a 0.200M
solution?
Answer:
18 g
Explanation:
We'll begin by converting 500 mL to L. This can be obtained as follow:
1000 mL = 1 L
Therefore,
500 mL = 500 mL × 1 L / 1000 mL
500 mL = 0.5 L
Next, we shall determine the number of mole of the glucose, C₆H₁₂O₆ in the solution. This can be obtained as follow:
Volume = 0.5 L
Molarity = 0.2 M
Mole of C₆H₁₂O₆ =?
Molarity = mole / Volume
0.2 = Mole of C₆H₁₂O₆ / 0.5
Cross multiply
Mole of C₆H₁₂O₆ = 0.2 × 0.5
Mole of C₆H₁₂O₆ = 0.1 mole
Finally, we shall determine the mass of 0.1 mole of C₆H₁₂O₆. This can be obtained as follow:
Mole of C₆H₁₂O₆ = 0.1 mole
Molar mass of C₆H₁₂O₆ = (12×6) + (1×12) + (16×6)
= 72 + 12 + 96
= 180 g/mol
Mass of C₆H₁₂O₆ =?
Mass = mole × molar mass
Mass of C₆H₁₂O₆ = 0.1 × 180
Mass of C₆H₁₂O₆ = 18 g
Thus, 18 g of glucose, C₆H₁₂O₆ is needed to prepare the solution.
Beer's Law states that A=ebc, where A is the absorbance, ε is the molar absorptivity of the solute, b is the path length, and c is the concentration. Identify the experimental evidence from the activity that you have for the dependence of absorbance on each variable
The evidence for the dependence of absorbance on the variable ε is:_________
a. increasing the cuvette width increases the absorbance.
b. changing the compound changes the absorbance behavior.
c. adding more water decreases the absorbance.
Answer:
b. changing the compound changes the absorbance behavior.
Explanation:
Option a) would be akin to modifying the path length, b.Option b) would involve using a different solute, as such, there would be another molar absortivity, ε.Option c) would decrease the concentration (c) of the solute, which would explain why the absorbance would decrease as well.Write the precipitation reaction for cobalt(II) hydroxide in aqueous solution: Be sure to specify the state of each reactant and product.
Answer:
The equation for the precipitation reaction of cobalt (ii) hydroxide is given below:
CoSO₄ (aq) + NaOH (aq) ----> Co(OH)₂ (s) + Na₂SO₄ (aq)
Explanation:
Cobalt (ii) hydroxide is an inorganic compound consisting of cobalt (ii) ions, Co²+ and hydroxide ions, OH-. It is insoluble in water and the pure form known as the beta form is a pink-coloured solid. The impure form which incorporates other anions in its molecular structure is blue in colour and is ustable.
Cobalt (ii) hydroxide is formed as precipitate when an alkaline metallic hydroxide such as sodium hydroxide is mixed with an aqueous cobalt (ii) salt such as cobalt (ii) sulfate. The equation for the precipitation reaction of cobalt (ii) hydroxide is given below:
CoSO₄ (aq) + NaOH (aq) ----> Co(OH)₂ (s) + Na₂SO₄ (aq)
Being a basic hydroxide, cobalt (ii) hydroxide neutralizes acids to form cobalt (ii) salts and water. For example: Co(OH)₂ (s) + H₂SO₄ (aq) ---> CoSO₄ (aq) + H₂O
Thus, cobalt (ii) hydroxide is soluble in acids.
Cobalt(II) hydroxide is used mostly as a drying agent for paints, varnishes, and inks. It is also useful in the preparation of other cobalt compounds.
Phosphorus trichloride can be made by the following reaction: P4(s) 6Cl2(g) - 4) 4PCl3(l) What is the maximum amount of phosphorus trichloride that can be formed if 15 molecules of P4 are mixed with 42 molecules of chlorine
Answer:
48 molecules
Explanation:
From the given reaction:
[tex]\mathtt{P_4 + 6Cl_2\to 4PCl_3}[/tex]
i.e. 1 mole of Phosphorus react 6 moles of chlorine to yield 4 moles of PCl₃
This implies that for each P₄ molecule, we will require 6 molecules of Cl₂
We are provided with 15 molecules of P₄ and 42 molecules of Cl₂
Suppose we utilized the whole 15 molecules of P₄, we will require:
= 15 × 6 = 90 moles of Cl₂ which is not readily available except 42 are available.
If we utilized 42 molecules of Cl₂, we will require 42/6 = 7 molecules of P₄ which is readily available.
From this analysis, we can opine that Cl₂ serves as the limiting agent
∴
P₄ : Cl₂ : PCl₃ = 1 : 6 : 4 = 7 : 42 : 48
It implies that only 48 molecules of phosphorus trichloride will be formed.
What is the volume of alcohol present in 200.0 mL of a 55\%(v/v) solution of alcohol ?
Answer:
110 mL
Explanation:
Equation for % v/v (volume concentration) is:
volume concentration = volume of solute / volume of solution
[tex]55\% v/v = v_{solute} /200\\v_{solute} =200 \times 55\%\\v_{solute} =110[/tex]
Draw the structural formula for both of these alcohols:
2,3, 4-trimethyl, 3-heptanol
4-ethyl, 4-octanol
Answer:
Check the image above
explanation:
When naming organic compounds based on IUPAC; we take note of functional group, position of functional group.
In 2,3,4-trimethyl-3-heptanol, the functional group is hydroxyl group ( OH ). It is on position 3 (2,3,4-trimethyl-3-heptanol. Then we put it on the third carbon. Another functional group is methyl group, with three positions, 2, 3, and 4.
In 4-ethyl-4-octanol, the functional group is hydroxyl group ( OH ) which is in position 4 on the fourth carbon. Another functional group is ethyl group in position 4 on the fourth carbon. In this case, the functional groups that have same position, are put on that same carbon.
