Exam 3 Review

Name that compound

100

HNO₃

nitric acid

200

hydrobromic acid

HBr

300

CuCl₂

copper (II) chloride

400

phosphorous acid

H₃PO₃

Acids, bases and pH

100

If the concentration of [H₃O⁺] in a solution is 1.0 x 10^-3 M what is the pH of the solution?

pH = -log[H₃O⁺] 

pH = 3

200

If the concentration of [OH^-] in a solution is 1.0 x 10^-4 M what is the pH of the solution?

pOH = -log[OH⁻]

pH = 14 - pOH  

pH = 10

 

300

Strontium hydroxide (Ba(OH)₂) is a strong base. What is the [OH^-] in a 0.050 M solution of barium hydroxide?

2 mol OH^- per 1 mol Ba(OH)₂

[OH^-] = 0.10 M

400

Strontium hydroxide (Ba(OH)₂) is a strong base. What is the pH of a 0.050 M solution of barium hydroxide?

[OH-] = 0.10 M 

pOH=−log[OH−]=−log(0.100)=1.00 

pH=14.00−pOH=14.00−1.00=

13.00

Thermo 101

100

Which of the following are state functions?

- work

- change in temperature

- heat

- change in pressure

change in temperature and change in pressure

200

Which of the following substances would have the smallest change in temperature, assuming they are the same mass?

- Water

- Copper

- Iron

-Aluminum

Water (highest specific heat capacity = smallest temperature change)

300

Calcium chloride is dissolved in water. The temperature of the solution increases. What is the sign of energy change for the system? (assume the dissolution is the system)

-q

400

A 2.50-gram sample of sodium hydroxide (molar mass = 40.00 g/mol) is combined with excess sulfuric acid. The mass of the resulting solution is 45.0 grams. The temperature of the solution increased from 18.50°C to 21.00°C. Calculate q_rxn in kJ. Assume that the specific heat capacity for the solution is the same as water. Round your answer to 3 significant figures.

q_rxn + q_soln = 0

q_soln=45.0×4.18×2.50=470.25 J

q_rxn = -0.470 kJ 

Titrations

300

Ammonia (NH₃) reacts with hydrochloric acid (HCl) to form ammonium chloride (NH₄Cl). 50.0 mL of 0.500 M NH₃ is neutralized by 100.0 mL of HCl. If you are being asked to find the molarity of HCl, what is the analyte and what is the titrant?

Analyte - Hydrochloric acid

Titrant - Ammonia

400

Ammonia (NH₃) reacts with hydrochloric acid (HCl) to form ammonium chloride (NH₄Cl). If 50.0 mL of 0.500 M NH₃ is neutralized by 100.0 mL of HCl, what is the molarity of the HCl solution? (Assume a 1:1 molar ratio between NH₃ and HCl.)

0.250 M