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1.	The temperature of air in closed space is observed to be `15^(@)C` and the dew point is `8^(@)C`. If the temperature falls to `10^(@)C` how will the dew point be affected? (Saturated vapour pressure at `7^(@)C=7.49mm` of mercury and that at `8^(@)C=8.02mm`)
Answer» Correct Answer - `7.74^(@)C`

2.	A mas of air is saturated with water vapour at `100^(@)C`. Onl raising the temperature to `200^(@)C` without change of volume, the mixture exerts a pressure of `2xx10^(5)` pascals (Pa). What was the pressure of air alone in the ilnitial conditions? (Saturated vapour pressure of water at `100^(@)C=10^(5)Pa`)
Answer» Correct Answer - `1.54xx10^(5)Pa`

3.	On a certain day the temperature of the air is s`30^(@)C` and relative humidity `50%`. What fraction of the mass of water vapour would condense if the temperature fell to `10^(@)C`? [Saturated vapour pressure at `30^(@)C=31.7mm` and `10^(@)C=9.2mm`]
Answer» Correct Answer - `0.40`

4.	Two chambers containing `m_(1)` and `m_(2)` kg of gas at pressure `p_(1)` and `p_(2)` are later connected. What will be pressure of the mixture.
Answer» Correct Answer - `((m_(1)+m_(2))p_(1)p_(2))/(m_(1)p_(2)+m_(2)p_(1))`

5.	Two gases which are at pressure `p_(1)` volume `V_(1)` and temperature `T_(1)` and pressure `p_(2)` volume `V_(2)` and temperature `T_(2)`, respectively are forced into a vessel of volume `V` at temperature `T`. Calculate pressure of the mixture.
Answer» Correct Answer - `T/V((p_(1)V_(1))/(T_(1))+(p_(2)V_(2))/(T_(2)))`

6.	Two vessels of equal capacity are connected together by a narrow tube of negligible volume. The contai a gas at atmospheric pressure and `27^(@)C`. One is cooled to `0^(@)C` and the other is heated to `100^(@)C`. Calculate the resulting pressure, assuming that the volume of the vessels remains unchanged.
Answer» Correct Answer - `79.9cm` of mercury

7.	Calculate the mass of 1 liter of moist air at `27^(@)C` when the barometer reads `753.6mm` of mercury and the dew point is `16.1^(@)C`. (Saturated vapour pressure of water at `16.1^(@)C+13.6mm` of mercury, densityb of aire at `NTP=1.293kg m^(-3)` and density of saturated water vapour at `NTP=0.808kg m^(-3)`
Answer» Correct Answer - `1.1589xx10^(-3)kg`

8.	A certain quantity of vapour of a liquid mixed with air is containe din a vessel of constant volume. The pressure shown at `20^(@)C` and `80cm` of mercury and at `40^(@)C` it is `100cm`. The vapour pressure of the liquid at `20^(@)C` is `15cm` of mercury. Calculate the same at `40^(@)C`.
Answer» Correct Answer - `30.6cm` of mercury

9.	A volume occupied by a saturated vapour is reducd `n` times at a constant temperature. What fraction `eta` of the final volume is occupied by the liquid if the specific volume of saturated vapour be `N` times greatr than the specific volume of the corresponding liquid?
Answer» Correct Answer - `(n-1)/(N-1)`

10.	Ten litres of dry ailr at atmospheric pressure and `0^(@)C` are contained in a closed vessel. Three grams of water are added and the system is heated to `100^(@)C`. Find the pressure in the vessel.
Answer» Correct Answer - `1.895xx10^(5) Pa`

11.	Find the massof 1 cubicmetre of moist air at `27^(@)C`s and `759.2mm` pressure, the dew point being `10^(@)C`. (Saturated vapour pressure at `10^(@)C=9.2mm`. Density of dry air at STP `=1.293 kg m^(-3)`. Density of moisture at any temperature and pressure `=5/8` of density of dry air at the same temperature and pressure.)
Answer» Correct Answer - `1.1699kg`

12.	A certain mass of saturated water vapour is contained in a cylindrical vessel under a weightless piston at one atmosphric pressure. The piston is slowly lowered till `0.7g` of vapour gets condensed. The volume under thepiston is now only `1/5` th of the original volume. Find the original mass of the vapour. Neglect volume of the liquid formed. What is the temperature of the vapour?
Answer» Correct Answer - `1.14g, 100^(@)C`

13.	The saturated water vapour is enclosed in a cylinder under a piston and occupies a volume of 5 litres at `100^(@)C`. Find the mass oif th water formed after the volume under the piston is decreased to `1.6 `litres at the same temperature.
Answer» Correct Answer - `0.94g`