a. Limestone (CaCO3) is decomposed by heating to quicklime (CaO) and carbon dioxide. Give

the balanced equation for the reaction and calculate the mass of quicklime produced from

1.000 kg of limestone.

b. An iron (Fe) bar weighed 664 g. After the bar had been standing in moist air for a month,

exactly one-eighth of the iron turned to rust (Fe₂O3) as shown in the reaction below.

Calculate the final total mass of the iron bar and rust. Molar mass of Fe₂O₂ is 159.7 g/mol.

4 Fe+30₂ - 2Fe₂O₂

c. In a laboratory, a student was doing a homogeneous reaction. She placed 0.300 mol of

PCI; (g) and 0.140 mole of Cl₂ (g) in 1.5 L of water at 250°C. After the following reaction

came to equilibrium, it was found that the equilibrium concentrations of PCI2, PC15, Cl₂ are

0.170 M, 0.078 M, 0.025 M respectively.

P Cl₂(g) + Cl(g) =PC15(9)

What were the initial concentration of the reactants? (Hint - Unit of concentration is

M or mol/L)

Write the equilibrium constant expression for this reaction.

What is the value of Kc for this reaction at this temperature?

Although the forms of the equilibrium constant and the reaction quotient appear

similar, they differ in one crucial aspect. What is the difference between the two?

How will the amount of PCI; (g) present in an equilibrium mixture of those gases be

affected by the following? Explain your answer.

(a) Adding PCl₂ (g)

(b) Increasing the volume to the reaction vessel

(c) Adding catalyst