States of Matter - exam practice

The gas laws can be summarised in the ideal gas equation.

pV = nRT

0.960 g of oxygen gas is contained in a vessel of volume 7.00 × 10^-3 m³ at a temperature of 30°C.

Assume that the gas behaves as an ideal gas.

What is the pressure in the vessel?

Which gas sample contains the fewest molecules?

In an experiment to identify a group 2 metal (X), 0.102 g of X reacts with an excess of aqueous hydrochloric acid according to the following equation.

X + 2HCl ➔ XCl₂ + H₂

The volume of hydrogen gas given off is 65 cm³ at 99 kPa pressure and 303 K.

The gas constant is R = 8.31 J K^–1 mol^–1.

Which is X?

When heated, a sample of potassium chlorate(V) (KClO₃) produced 67.2 cm³ of oxygen, measured at 298 K and 110 kPa

2KClO_3(s) ➔ 2KCl_(s) + 3O_2(g)

What is the amount, in moles, of potassium chlorate(V) that has decomposed?

The gas constant, R = 8.31 J K^–1 mol^–1.

Metals are good conductors of electricity because

The melting temperature of sodium is lower than the melting temperature of magnesium. The best explanation for this is

Which statement about ideal gases is correct?

Which would behave the leastlike an ideal gas at room temperature?

The general gas equation can be used to calculate the M_r value of a gas.

For a sample of a gas of mass mg, which expression will give the value of M_r?

Which gas closely approaches ideal behaviour at room temperature and pressure?

What is a basic assumption of the kinetic theory, as applied to an ideal gas?

What is the effect on the volume when the pressure of an ideal gas is doubled at the same time as the temperature (in K) is doubled?

Which set of elements in the solid state contain a simple molecular lattice, a giant covalent lattice and a giant metallic lattice?

Which statement about the molecules in a sample of a gas is correct?