In the reaction, Ca + 2H2O = Ca(OH)2 + H2; what volume (c.c.) of hydrogen at STP would be liberated, when 8 gm of calcium reacts with excess water ? (Atomic weight of calcium = 40) ?

Related Mcqs:

1. 6 gms of magnesium (atomic weight = 24), reacts with excess of an acid, the amount of H2 produced will be ______________ gm?

   A. 0.5
   B. 1
   C. 3
   D. 5

2. The atomic weight of helium is 4 times that of hydrogen. Its diffusion rate as compared to hydrogen will be _____________ times?

   A. 1/2
   B. 4
   C. √2
   D. 1/4

3. What is the simplest formula of a compound containing 50% of element A (atomic weight = 10) and 50% of element B (atomic weight = 20) ?

   A. AB3
   B. A2B3
   C. A2B
   D. AB2

4. If 1.5 moles of oxygen combines with aluminium to form Al2O3, then the weight of aluminium (atomic weight = 27) used in this reaction is __________ gm?

   A. 27
   B. 54
   C. 5.4
   D. 2.7

5. One mole of methane undergoes complete combustion in a stoichiometric amount of air. The reaction proceeds as CH4 + 2O2 → CO2 + 2H2O. Both the reactants and products are in gas phase. ΔH°298 = – 730 kJ/mole of methane. Mole fraction of water vapour in the product gases is about_____________________?

   A. 0.19
   B. 0.33
   C. 0.40
   D. 0.67

6. 1 kg of calcium carbide (CaC2) produces about 0.41 kg of acetylene gas on treatment with water. How many hours of service can be derived from 1 kg of calcium carbide in an acetylene lamp burning 35 litres of gas at NTP per hour ?

   A. 5
   B. 10
   C. 15
   D. 20

7. A vessel of volume 1000 m3 contains air which is saturated with water vapour. The total pressure and temperature are 100 kPa and 20°C respectively. Assuming that the vapour pressure of water at 20°C is 2.34 kPa, the amount of water vapour (in kg) in the vessel is approximately ?

   A. 17
   B. 20
   C. 25
   D. 34

8. A sample of well water contains 140 gm/m3 Ca2+ ions and 345 gm/m3 Na+ ions. The hardness of the sample of water, expressed in terms of equivalent CaCO3 in gm/m3 is (assuming atomic masses of Ca :40, Na : 23, C : 12, O : 16) ?

   A. 350
   B. 485
   C. 140
   D. 345

9. The amount of Zn (atomic weight = 65) required to form 224 c.c. of H2 at N.T.P. on treatment with dilute H2SO4will be _____________ gm?

   A. 0.065
   B. 0.65
   C. 6.5
   D. 65

10. One kg of saturated steam at 100°C and 1.01325 bar is contained in a rigid walled vessel. It lias a volume of 1.673 m3. It cools to 98°C; the saturation pressure is 0.943 bar ; one kg of water vapour under these conditions has a volume of 1.789 m3. The latent heat of condensation (kJ/kg-1 ) under these conditions is___________________?

    A. 40732
    B. 2676
    C. 2263
    D. 540