lf equal moles of water and urea are taken in a vessel,The mass percentage of urea in the solution will be -

1. 22.086

2. 11.536

3. 46.146

4. 76.92

Sodium bicarbonate on heating decomposes to form sodium carbonate, CO₂ and water. If 0.2 moles of sodium bicarbonate is completely decomposed, how many moles of sodium carbonate is formed?

1. 0.1

2. 0.2

3. 0.05

4. 0.025

A purified pepsin was subjected to amino acid analysis. The amino acid present in the smallest amount was lysine, C₆H₁₄N₂O₂ and the amount of lysine was found to be 0.431g per 100 g of protein. The minimum molecular mass of protein is:

1. 34 u

2. 3400 u

3. 34,000 u

4. 3,400,000 u

The number of valence electrons present in 0.53 grams of Na₂CO₃ is:

1. $3.01\times {10}^{23}$

2. $7.22\times {10}^{22}$

3. $12.046\times {10}^{23}$

4. $6.023\times {10}^{23}$

At STP, the density of CCl₄ vapour in g/L will be closest to: 

1. 8.67

2. 6.87

3. 3.67

4. 4.26

If $3.02\times {10}^{19}$ molecules are removed from 98 mg of H₂SO₄, then the number of moles of H₂SO₄ left are -

1. $0.1\times {10}^{-3}$

2. $9.5\times {10}^{-4}$

3. $1.2\times {10}^{-4}$

4. $0.5\times {10}^{-3}$

A chloride of a metal (M) has 65.5% of chlorine. 100 ml of vapour of the chloride of metal at STP weighs 0.72 g. The molecular formula of this metal chloride is

1. MCl₃ 

2. MCl₄ 

3. M₂Cl₃ 

4. MCl₅ 

The molality of 0.01 M Na₂CO₃ solution is:
(The density of the solution is 1.1 g/ml)

1. $9\times {10}^{-3}$

2. $1.8\times {10}^{-3}$

3. $4.5\times {10}^{-3}$

4. $1.1\times {10}^{-3}$

The weight of 1x10²³ molecules of CuSO₄.5H₂O is: 

1. 34.42 g

2. 41.42 g

3. 54.44 g

4. 68.94 g

lf N_A is Avogadro's number, then the number of valence electrons in 4.2 g of nitride ions (N${}^{3-}$) will be: