**211. Pure oxygen is mixed with air to produce an enriched air containing 50 volume % of oxygen. The ratio of moles of air to oxygen used is_________________?**

A. 1.72**B. 0.58**

C. 0.5

D. 0.2

**212. One ‘Therm’ is equivalent to___________________?****A. 105 BTU**

B. 105 kcal

C. 109 BTU

D. 109 kcal

**213. The value of (Cp – Cv) for a real gas obeying Vander Wall’s equation is____________________?**

A. R**B. > R**

C. < R

D. 0.5 R

**214. In _______________ process, ions of salts react with water to produce acidity or alkalinity ?**

A. Hydration**B. Hydrolysis**

C. Electrolysis

D. Dialysis

**215. For the gaseous phase reaction, N2 + O2 ⇌ 2NO, ΔH = + 80 kJ/kg. mole; the decomposition of NO is favored by____________________?**

A. Increasing the concentration of N2**B. Decrease in temperature**

C. Increase in pressure

D. Decrease in pressure

**216. 1 Kcal/kg. °C is equivalent to _______________ BTU/lb. °F ?****A. 1**

B. 2.42

C. 4.97

D. None of these

**217. A fluid gas produced on burning furnace oil contains 0.15 gm mole of CO2, 0.05 gm mole of oxygen and 0.80 gm mole of N2. What is its molecular weight ?**

A. 28.6

B. 30.0**C. 30.6**

D. 32.6

**218. A gas at 0°C was subjected to constant pressure cooling until its volume became half the original volume. The temperature of the gas at this stage will be________________**?

A. 0°C

B. 0°K**C. -136.5°C**

D. -136.5°K

**219. 500 c.c. each of hydrogen at 700 mm Hg pressure and oxygen at 600 mm Hg pressure are put together in a vessel of 1 litre capacity. The final pressure of the gas mixture will be _____________ mm Hg?****A. 650**

B. 700

C. 600

D. 375

**220. A car tyre of volume 0.057 m3 is inflated to 300 kPa at 300 K. After the car is driven for 10 hours, the pressure in the tyre increases to 330 kPa. Assume air is an ideal gas and Cv for air is 21 J/mole.K. The change in the internal energy of air in the tyre in J/mole is__________________?**

A. 380**B. 630**

C. 760

D. 880