1. For KNO₃ the heat of solution is 23.8 kJ/mol and the lattice energy is -685.0 kJ/mol. Calculate the heat of hydration.

2. 60.3 g of zinc sulfate [ZnSO₄], is added to 160. g of water. Will the salt dissolve completely and, if so, will the solution be saturated or unsaturated? The solubility of ZnSO₄ is 3.57 m.

3. What volume of water, in mL, is needed to dissolve 2.2 mg of hydrogen gas when the partial pressure of hydrogen above the water is 2.2 atm at 25 °C? The Henry's constant for hydrogen gas in water at 25 °C is 7.8×10^-4 M/atm.

PLEASE ANSWER ALL 3 QUESTIONS.

Answer the following and express your answer using two significant figures.

Calculate the final concentration of each of the following diluted solutions.

A) 3.5 L of a 4.0 M HNO3 solution is added to water so that the final volume is 8.0 L .

B) Water is added to 0.15 L of a 6.0 M KOH solution to make 2.0 L of a diluted KOH solution.

C) A 35.0 mL sample of 8.0 % (m/v) NaOH is diluted with water so that the final volume is 200.0 mL .

D) A 6.0 mL sample of 50.0 % (m/v) acetic acid (HC2H3O2) solution is added to water to give a final volume of 25 mL .

A sample that contains only BaCO3 and MnCO3 weighs 0.8192 g. When it is dissolved in excess acid, 0.2420 g of carbon dioxide is liberated. What percentage of BaCO3 did the sample contain? Assume all the carbon originally present is converted to carbon dioxide.

You prepare a solution by dissolving 50.4g sucrose (C12H22O11) in 0.332 kg of water. The final volume of the solution is 355 mL. Calculate the concentration of the solution in each unit.
1 mole C12H22O11 = 342.296 g sucrose

(a) Molarity
(b) Molality
(c) Percent by mass
(d) Mole fraction

Calculate the mass and volume of 150 mmol of benzaldehyde, and the theoretical yields of benzoin, benzil, and benzilic acid expected from that much benzaldehyde. I'm pretty sure that you use 2 mol of benzaldehyde per 1 mol of the other compounds, but you might want to check to make sure.

Please calculate the theoretical yield in grams. Thank you very much.

I don't understand this at all so the more detailed explaination would be amazing, thanks!

part B: How many grams of NH3 can be produced from 3.34 mol of N2 and excess H2.

Express your answer numerically in grams.

Part C: How many grams of H2 are needed to produce 13.73 g of NH3?

Express your answer numerically in grams.

Part D: How many molecules (not moles) of NH3 are produced from 3.50×10⁻⁴ g of H2?

Express your answer numerically as the number of molecules.

a sample of water collected in the field had a pH of 6.8. by the time the water sample reached the laboratory for analysis the pH had increased to 7.5. give a possible explanation for this sample change.

Answer the following and express your answer using two significant figures. Calculate the grams of solute needed to prepare each of the following solutions.

A) 1.6 L of a 4.5 M NaOH solution

B) 7.0 L of a 0.20 M CaCl2 solution

C) 180 mL of a 3.50 M NaNO3 solution

9. Calculate the freezing point and boiling point of the following aqueous solutions, assuming
complete dissociation:
(a) 10.5 g FeCl3 in 1.50

WK 11: In the study of oxidation/reduction reactions, what is meant by "spectator ions"? Give an example in a chemical reaction.

Titanium metal requires a photon with a minimum energy of 6 .9 4 * 1 0 - 1 9 J to emit electrons. ( a ) What is the minimum frequency of light necessary to emit electrons from titanium via the photoelectric effect? ( b ) What is the wavelength of this light? ( c ) Is it possible to eject electrons from titanium metal using visible light? ( d ) If titanium is irradiated with light of wavelength 233 nm, what is the maximum possible kinetic energy of the emitted electrons? ( d ) What is the maxi - mum number of electrons that can be freed by a burst of light whose total energy is 2 . 0 0 m J ?

1. Why is it impossible for greater than 96% pure ethanol to be obtained from fractional distillation of the fermentation mixture?

2. In terms of the velocity of light, what is refractive index?

3. Does your graph of the simple and fractional distillations show any difference in the shapes of the two curves? What does this difference, if any; indicate about the efficiency of fractional distillation relative to that of simple distillation for separating the ethanol/water azeotrope from water?

4. A compound has a refractive index of 1.3191 at 20.0oC. Calculate its refractive index that would be expected at 25.0oC.

I DO NOT have a specific question, my question here is GENERAL

HOW TO DETERMINE IF A COMPOUND IS POLAR OR NONPOLAR?

I know how to figure about the number of valence electrons and I KNOW how to draw lewis structure, but then I just mess every thing up. I want to know how to determine if it's polar or not.

for example: sicl2f2, co2, xef2, xeo4 ... I KNOW how to draw the lewis structure, but this I CANNOT decide whether they are polar or not.

so please if someone knows or can explain an easy way to figure it. the book keeps mentiong symmetric and asymmetric but it just did not help

When an ion-selective electrode for X was immersed in 0.0760 M XCl, the measured potential was 0.0450 V. What is the concentration of X when the potential is 0.0600 V? Assume that the electrode follows the Nernst equation, the temperature is at 25°C, and that the activity coefficient of X is 1.

[X+] = ??M

An elastic (stretchable) balloon made of a material that is permeable to water but not to any solutes is filled with an aqueous solution containing 0.1 M glucose and 0.3 M NaCl. The balloon is then sealed and completely immersed in an second aqueous solution with NaCl as the only solute. The balloon does not expand or contract. What is the concentration of NaCl in the solution that the balloon was immersed in (the second solution)? Assume all salts undergo complete dissociation.