2. a) A student obtained ice at 0°C from a refrigerator and placed it in a beaker on a bench. After 4 minutes, the temperature rose to 4°C. State the changes that would be observed in the water in terms of;
(i) volume
(ii) mass
(iii) density

(b) Sketch a graph of density against temperature if the ice is warmed from 0°C to
8°C.

Which changes of state do the labels represent? a: b: c:

An ideal gas is held in a container at constant volume. initially, its temperature is 5 degrees c and its pressure is 1.2 atm. what is its pressure when its temperature is 43 degrees c? answer in units of atm

Air is to be preheated by hot exhaust gases in a cross-flow heat exchanger before it enters the furnace. air enters the heat exchanger at 95 kpa and 20°c at a rate of 0.6 m^3/s. the combustion gases (cp = 1.10 kj/kg°c) enter at 160°c at a rate of 0.95 kg/s and leave at 95°c. determine the rate of heat transfer to the air and its outlet temperature.