Fig. 2.1 shows a container of gas connected to a manometer. The tube in the manometer has a constant cross-sectional area. The gas in the container exerts a pressure. [Figure 2.1]

1. (a)Define the term pressure.[1]
2. (b)The density of mercury is 1.4 × 10⁴ kg/m³. The gravitational field strength g is 10 N/kg. The pressure of the atmosphere is 1.0 × 10⁵ Pa. Calculate the pressure of the gas in the container.[3]
3. (c)(i)In Fig. 2.1, the mercury level on the left-hand side of the manometer is lower than on the right-hand side. The gas inside the container is heated. This causes the mercury levels on both sides to become the same. Determine the mercury level, as shown on the ruler, when this happens.[1]
4. (c)(ii)Explain, in terms of the gas molecules, what causes the level of mercury to become the same.[3]

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