Inorganic Chemistry Answers

1. Acids and Bases

1. What is the pH of a solution of HCl with a concentration of 1.2 X 10-3 M?

2. The pH of a 0.0516 M solution of nitrous acid, HNO2, is 2.34. What is its Ka?

From periodic table explain the following; Cl‐1, Li 1, Mg +2, S6, Cs +1, Al +3, O -2 and Ca +2

Lead metal is obtained from lead sulfide through the following reaction:

2PbS(s) + 2C(s) + 3O₂(g) → 2Pb(s) +2CO(g) + 2SO₂(g)

(a)If 100g of PbS is reacted with excess C and O_2, calculate the mass of lead metal obtained. ( 5 )

(b)Suppose 100 g of PbS is reacted with 4g of C and 20g O₂.

Find the limiting reactant for this reaction.

( 4 )

(c)For question (b) above, calculate the mass of lead metal obtained. ( 4 )

(d)By referring to the question (c) above, If 31.2g Pb is obtained as the yield. Calculate the percentage of yield. ( 2 )

(e)Calculate mass of oxygen is needed to produce 500g of lead metal.

1. Calculate the amount of heat required to raise the temperature of 7.25g of liquid water from 22.7^oC to 29.2^oC.
2. Calculate the amount of heat required to evaporate 5.20g of liquid water
3. Calculate the amount of heat to be released when 6.50g of water vapor condenses.
4. What phenomenon is responsible for the maximum temperature at the boundary of the stratosphere and the atmosphere?
5. What function does a third body serve in an atmospheric chemical reaction?
6. Why does the lower boundary of the ionosphere lift at night?

Using the appropriate gas laws, calculate the quantities denoted by the blanks below.

Conditions before Conditions after

n₁, mol V₁, L P₁, atm T₁, K n₂, mol V₂, L P₂, atm T₂, K

1.25 13.2 1.27 298 1.25 (a)___ 0.987 298

1.25 13.2 1.27 298 1.25 (b)___ 1.27 407

1.25 13.2 1.27 298 4.00 (c)___ 1.27 298

1.25 13.2 1.27 298 1.36 (d)___ 1.06 372

1.25 13.2 1.27 298 1.25 30.5 (e)___ 298

Calculate the molar concentration of solute in the following:

1. 7.59g of NH₃ in 1.500L solution.
2. 0.291g of H₂SO₄ in 8.65L solution.
3. 85.2g of NaOH in 5.00L solution.
4. 31.25g of NaCl in 2.00L solution.
5. 6mg of atmospheric N₂ in water with volume of 2.00L.

1. Concentrated sulphuric acid is a solution that has a density of 1.84 g/ml and contains 98.3

% H2SO4 by mass. What is the molarity of this acid?

2. What is the molality of a solution that contains 0.850 g of ammonia, in 125 g of water?

3. How would you distinguish molarity, molality and normality?

A closed system initially containing 1.000 × 10-3 M H2 and 2.000 × 10-3 M I2 at 448°C is allowed to reach

equilibrium.At equilibrium, the HI concentration is 1.87 × 10-3 M. Given that the reaction equation is H2(g) + I2(g)

↔ 2 HI(g), find:

a. Equilibrium concentrations of the two reactants

b. Kc of the reaction taking place.

Describe how scientist would proceed from the formulation of a question to the establishment of theory

Interpret the following equations in words?

A. CoCl2(s) + 2 HF(g) – CoF2(s) + 2 HCl(g)

B. Pb(NO3)2(aq) + 2 KI(aq) – PbI2(s) + 2 KNO3(aq)