Chap 5 - 9 Review Paper 1 Q's

What is the volume of steam produced when 1.00 g of ice is heated to 323 degrees Celsius at a pressure of 101 kPa

• 0.27 dm³

• 1.3 dm³

• 2.7 dm³

• 48 dm³

Solid carbon dioxide, CO₂, is similar to solid iodine, I₂, in its structure and properties. Carbon is in Group 14. Silica, SiO₂ is a group 14 compound. Which statement about solid CO₂ and solid SiO₂ is correct?

• Both solids exist in a lattice structure.

• Both solids have a simple molecular structure.

• Both solids have atoms joined by single covalent bonds.

• Both solids change spontaneously to gas at s.t.p.

An article in a science magazine contains the following statement. 'It is lighter than a feather, stronger than steel, yet incredibly flexible and more conductive than copper'. Which form of carbon is being described?

• Buckminsterfullerine

• Diamond

• Graphene

• Graphite

Which equation has an enthalpy change of reaction which corresponds to the enthalpy change of atomization of Chlorine?

• 1/2 Cl₂(g) --> Cl(g)

• 1/2 Cl₂(l) --> Cl(g)

• Cl₂(g) --> 2 Cl(g)

• Cl₂(l) --> 2 Cl(g)

In an experiment, 2.00 mol of hydrogen and 3.00 mol of iodine were heated together in a sealed container and allowed to reach equilibrium at a fixed temperature. The container had a fixed volume of 1.00 dm³. At equilibrium there were 2.40 moles of iodine present in the mixture.

Equation : H_2(g) + I_2(g) <--> 2 HI(g)

What is the value of the equilibrium constant, Kc ?

• 0.107

• 0.357

• 0.429

• 2.33

Which statement(s) about reversible reactions are correct?

1 An increase in concentration of a reactant always increases the concentration of the product

2 An increase in temperature always increases the rate at which equilibrium is established

3 An increase in temperature always increases the amount of the product at equilbrium

• 1, 2 and 3 are correct

• 1 and 2 are correct

• 2 and 3 are correct

• only 1 is correct

A chemist puts a sample of dilute aqueous hydrochloric acid into beaker 1. She adds a sample of zinc and measures the rate of production of hydrogen gas.

She then puts a different sample of dilute aqueous hydrochloric acid into beaker 2. She adds a different sample of zinc and measures the rate of production of hydrogen gas.

The rate of reaction in beaker 2 is greater than that in beaker 1.

Which factors could help explain this observation?

• The reaction in beaker 1 has a higher activation energy than the reaction in beaker 2.

• The zinc in beaker 1 is in larger pieces than the zinc in beaker 2.

• The acid in beaker 1 is at a lower concentration than the acid in beaker 2.

Solid sulfur consists of molecules made up of eight atoms covalently bonded together. The bonding in sulfur dioxide is O=S=O.

Enthalpy change of combustion of S₈ = -2376 kJ/mol

Energy required to break 1 mole S_8(s) into gaseous atoms = 2232 kJ/mol

O=O bond enthalpy = 496 kJ/mol

Using this data , what is the value of the S=O bond enthalpy?

• 239 kJ/mol

• 257 kJ/mol

• 319 kJ/mol

• 536 kJ/mol

In an experiment, the burning of 1.45 g (0.025 mol) of propane was used to heat 100 g of water. The initial temperature of the water was 20.0 degrees Celsius and the final temperature of the water was 78.0 degrees Celsius. Which experimental value for the enthalpy change of combustion for propanone can be calculated from these results?

• -1304 kJ/mol

• -970 kJ/mol

• -352 kJ/mol

• -24.2 kJ/mol

A mixture of nitrogen and hydrogen gases, at a temperature of 500 K, was put into an evacuated vessel of volume 6 dm³. The vessel was then sealed.

Equation N_2(g) + 3 H_2(g) <--> 2 NH_3(g)

The mixture was allowed to reach equilibrium. It was found that 7.2 mol of N₂ and 12.0 mol of H₂ were present in the equilibrium mixture. The value of the equilibrium constant, K_c , for this equilibrium is .06 at 500 K.

What is the concentration of ammonia present in the equilibrium mixture at 500 K?

• 0.58 mol / dm³

• 0.76 mol / dm³

• 3.5 mol / dm³

• 27 mol / dm³