Class 11 Chemistry

Chapter 1 – Basic Concepts of Chemistry

Assignment 2

 

Q.1. Calculate the mass of 1 molecule of naphthalene (C₁₀H₈).

Q.2. Calculate the mass of 1 u (atomic mass unit) in grams.

Q.3. Calculate the number of molecules and number of atoms present in 11.2 litres of oxygen at S.T.P.

Q.4. Calculate the number of atoms in 52 mol of Ar.

Q.5. Calculate the number of atoms in 52 u of He.

Q.6. Calculate the number of atoms in 52 g of He.

Q.7. Calculate the number of atoms of each type in 5.3 g of Na₂CO₃.

Q.8. Calculate the number of molecules present in 1 dm³ of hydrogen at S.T.P.

Q.9. The mass of 94.5 mL of a gas at S.T.P. is found to be 0.2231 g. Calculate its molecular mass.

Q.10. Calculate the actual volume of one molecule of water.

Q.11. Calculate the radius of a water molecule assuming to be spherical (density of water = 1 g ml⁻¹).

Q.12. Calculate the mass of sodium which contains same number of atoms as are present in 15 g of calcium (at. mass of Ca = 40, Na = 23).

 

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