Some Basic Concepts of Chemistry

35.4 ml of HCl is required for the neutralization of a solution containing 0.275 g of sodium hydroxide. The normality of hydrochloric acid is ?

• 0.97 N

• 0.142 N

• 0.194 N

• 0.244 N

Which of the following has the smallest number of molecules ?

• 0.1 mole of CO₂ gas

• 11.2 L of CO₂ gas at STP

• 22 g of CO₂ gas

• 22.4 x 10³ mL of CO₂ gas at STP

The value of amu is which of the following ?

• 1.57 × 10^-24 kg

• 1.66 × 10^-24 kg

• 1.99 × 10^-23 kg

• 1.66 × 10^-27 kg

4.6 x 10²² atoms of an element weigh 13.8g. The atomic weight of that element is

• 290

• 180

• 34.4

• 10.4

2g of mixture of CO and CO₂ on reaction with excess I₂O₅ produced 2.54g of I₂. What would be the mass% of CO₂ in the original mixture?

• 60

• 30

• 70

• 35

When 10g of 90% pure lime stone is heated completely, the volume (in litres) of CO₂ is liberated at STP is

• 22.4

• 2.24

• 20.16

• 2.016

Which one of the following has unit positive charge and 1 amu mass ?

• Electron

• Neutron

• Proton

• None of these

Law of constant composition is same as the law of

• conservation of mass

• conservation of energy

• multiple proportion

• definite proportion

By dissolving 5 g substance in 50 g of water, the decrease in freezing point is 1.2°C. The gram molal depression is 1.85°C. The molecular weight of substance is :

• 105.4

• 118.2

• 137.2

• 154.2

If molecular weight of KMnO₄ is M, then its equivalent weight in acidic medium would be

• M

• M/2

• M/5

• M/3