States of Matter

Place the following gases in decreasing order of ideal behaviour.

$\text{ammonia, neon, nitrogen}$

most ideal ..................................................................................................... least ideal

Explain your answer.

By using the kinetic-molecular model, explain why a liquid eventually becomes a gas as the temperature is increased.

Explain the general increase in melting point from Na to Al.

Explain the variation of melting points from P to Ar.

Explain why Si has a much higher melting point than any of the other elements in the period.

Bicycles may be carried on commercial airliners. When carried on airliners, bicycles are placed in the luggage hold. This is a part of the aircraft which, in flight, will have different temperatures and air pressures from those at sea level.

This question concerns the change in pressure in an inflated bicycle tyre from when it is at sea level to when it is in the hold of an airliner in flight.

At sea level and a temperature of 20 °C an inflated bicycle tyre contains $710 \text{ cm}^3$ of air at an internal pressure of $6 \times 10^5$ Pa.

Use the general gas equation $PV = nRT$ to calculate the amount, in moles, of air in the tyre at sea level.

The same bicycle, with its tyres inflated at sea level as described in (d) above, is placed in the luggage hold of an airliner. At a height of 10 000 m, the temperature in the luggage hold is 5 °C and the air pressure is $2.8 \times 10^4$ Pa.

Assuming the volume of the tyre does not change, use your answer to (d) to calculate the pressure inside the tyre at a height of 10 000 m.

Copper, ice, silicon(IV) oxide, iodine and sodium chloride are all crystalline solids.

Complete the table with:

• the name of a type of bonding found in each crystalline solid,
• the type of lattice structure for each crystalline solid.

Identify the state(s) of matter present during each stage of the process shown in the graph.

X .........................................................................................................................................

Y .........................................................................................................................................

Z .........................................................................................................................................

State what is happening to the energy and movement of the particles in the copper during stage X.

Draw one line on the graph to show what the relationship should be for the same amount of an ideal gas.

State and explain, with reference to the graph, which of $T_1$, $T_2$ or $T_3$ is the lowest temperature.

Explain your answer to (ii) with reference to intermolecular forces.

State and explain the effect of pressure on the extent to which a gas deviates from ideal behaviour.

A flask with a volume of 100 cm$^3$ was first weighed with air filling the flask, and then with another gas, Y, filling the flask. The results, measured at 26 °C and $1.00 \times 10^5$ Pa, are shown.

Calculate the relative molecular mass, $M_r$, of Y.

Which types of particle are present in the copper and argon crystals?
In each case, give their formula.

At room temperature, copper is a solid while argon is a gas.

Explain these observations in terms of the forces present in each solid structure.

State the two conditions necessary for these two gases to approach ideal gas behaviour.

Explain why N₂(g) behaves more like an ideal gas than CO(g) does at 20.0°C and 101kPa.

Calculate the amount, in mol, of pure nitrogen gas which occupies 100cm³ at 101kPa and 20.0°C.

Use relevant information from the Data Booklet. Show your working.

Assume nitrogen behaves as an ideal gas.

Name the type of lattice structure present in the crystalline solids diamond and graphite.

Explain how graphite conducts electricity.

Explain why diamond does not conduct electricity.

Complete Table 1.1 by identifying the strongest force of attraction in each oxide that is broken during melting. Use the abbreviations below.

i.d. = instantaneous dipole–induced dipole
p.d. = permanent dipole–permanent dipole
H = hydrogen bond
C = covalent bond
I = ionic bond

A student suggests the following hypothesis.

The stronger the covalent bond between atoms in non-metal oxides, the higher the melting point.

Use Table 1.1 to deduce if this hypothesis is true or false or if there is not enough information to make a conclusion. Explain your answer.

State two assumptions of the kinetic theory as applied to an ideal gas.

$2.00\text{ g}$ of krypton gas, $\text{Kr(g)}$, is placed in a sealed $5.00\text{ dm}^3$ container at $120\text{ }^\circ\text{C}$.

Calculate the pressure, in $\text{Pa}$, of $\text{Kr(g)}$ in the container.
Assume $\text{Kr(g)}$ behaves as an ideal gas.

Show your working.

State and explain the conditions at which krypton behaves most like an ideal gas.

Use the data given to calculate the value of $x$.

$x = \text{..............................}$

Use the data given to calculate the value of $y$.

$y = \text{..............................}$

Use the general gas equation to calculate the mass of T present in the original $20\text{ cm}^3$ gaseous sample, which was measured at $120\text{ }^\circ\text{C}$ and $100\text{ kPa}$.

Give your answer to three significant figures. Show your working.

$\text{mass} = \text{.............................. g}$