

Explanation
(a) Boiling point of a liquid is the temperature at which saturated vapour pressure of a liquid equals the external atmospheric pressure.
(b) Fill a round bottom flask partially with water, then pump out the air gradually with a vacuum pump. At a state when the saturation vapour pressure equal atmospheric pressure, the water is observed to be boiling.
(c) Application of i expansion of metals are in:
- Riveting two or more metal plates.
- Fixing of metal rims on metal wheels.
- Fusing of platinum wire through walls of glass vessels.
- Automatic fire alarms and
- Thermostat.
(d)(i) Volume = \(\frac{Mass}{Density} = \frac{250}{1.25}\)
= 200\(m^2\)
But volume = Ibh
h = \(\frac{v}{Ib} = \frac{200}{7 \times 10}\)
= 2.86m
(ii) Q = mc\(\theta\)
V = 250 x 1010(34 - 24)
= 252500 or 2.525 x 10\(^6\)
(iii) The actual energy value will be higher in value than the calculated value because --Part of heat is extracted. from the walls in the room and other materials. he room also is not airtight, there are heat leakages in and out of the room.

