Which of the following pairs of gases contains the same number of molecules:-

(1) 16g of O₂ and 14g of N₂ 

(2) 8g of O₂ and 22g of CO₂ 

(3) 28g of N₂ and 22g of CO₂ 

(4) 32g of O₂ and 32g of N₂ 

Calculate the number of ions present in 2L of a solution of 1.6 M K₄[Fe(CN)₆]:

The mass of CO₂ that shall be obtained by heating 10 kg of 80 % pure limestone (CaCO₃) is:

1. 4.4 kg

2. 6.6 kg

3. 3.52 kg

4. 8.8 kg

How many protons are present in 1.8g of ${{\mathrm{NH}}_4}^{+}$ :-

1. N_A

2. 1.2 N_A

3. 1.1 N_A

4. 11 N_A

When 1L of CO₂ is heated with graphite,the volume of the gases collected is 1.8L. What will be the number of moles of CO produced at STP?

1. 0.0357

2. 0.0714

3. 0.0803

4. 14

On reduction with CO, 200 kg of iron ore (Fe₂O₃) containing 20% impurities gives iron. The amount of iron produced will be-

1. 84 kg

2. 200 kg

3. 56 kg

4. 112 kg

At STP the moles of oxygen atoms in 2.8 L of CO₂ gas is:-

1. 0.125

2. 0.25

3. 0.5

4. 1

Identify the incorrect statement among the following:

1. 1 mol N^-3 ions have 10 mole electrons

2. 1 mol O^-2 ions have  6.023 x 10²² electrons

3. 1 mol CH₄ has 10 mole protons

4. 1 mol water has 10 mole protons

Mass of sucrose C₁₂H₂₂O₁₁ produced by mixing 84 gm of carbon, 12gm of hydrogen and 56L. O₂ at 1atm & 273 K according to give reaction, is C(s) + H₂(g) +O₂(g) $\to$ C₁₂H₂₂O₁₁ (s)

1. 138.5

2. 155.5

3. 172.5

4. 199.4

A mixture contains Na₂CO₃ and NaHCO₃ and wt. of mixture is 10gm. Mixture on heating liberates 56ml of CO₂ at S.T.P, wt of Na₂CO₃ in mixture is

1. 9.58 gm

2. 5 gm

3. 7.5 gm

4. 8 gm