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

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:

ln the final answer of the expression \(\large{\frac{(29.2-20.2)\times(1.79\times10^5)}{1.37}}\)
the number of significant figures after solving the expression is:

The amount of Zinc (atomic weight = 65) necessary to produce 224 mL of H₂ (at STP) by the reaction with dilute sulphuric acid will be: 

On complete decomposition, the volume of CO₂ released at STP on heating 9.85 g of BaCO₃ (atomic mass, Ba = 137) will be:

1. 1.12 L

2. 4.84 L

3. 2.12 L

4. 2.06 L

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. $6.023\times {10}^{23}$

1cc N₂O at STP contains: 

Which of the following statements is correct?

1. 1 mole of electrons weights 5.4 mg .
2. 1 mole of electrons weights 5.4 kg. 
3. 1 mole of electrons weights 0.54 mg. 
4. 1 mole of electrons has 1.6$\times {10}^{-19}$ C of charge.

The number of  moles  present in 2.5 litres of 0.2 M  ${\mathrm{H}}_2{\mathrm{SO}}_4$ are:

1. 0.25

2. 0.5

3. 0.75

4. 0.2