Q. No.224 ml of a triatomic gas weighs 1g at 273 K and 1 atm. The mass of one atom of this gas is:
1. 8.30 × 10–23 g
2. 2.08 × 10–23 g
3. 5.53 × 10–23 g
4. 6.24 × 10–23 g
Number of H-atom in 1.7 g of NH3 is:
(NA = Avogadro number)
1. NA
2. 0.1×NA
3. 0.3 × NA
4. 3 × NA
The relative molecular mass of calcium carbonate is 100. What is the minimum volume of 2.0 M hydrochloric acid that would be needed to completely react with 2.0 g of calcium carbonate?
| 1. 40 cm3 | 2. 20 cm3 |
| 3. 30 cm3 | 4. 5 cm3 |
Which of the following contains the maximum number of atoms ?
| 1. | 1 g of Mg(s) | 2. | 1 g of O2 (g) |
| 3. | 1 g of Li(s) | 4. | 1 g of Ag(s) |
The density of a 2 M aqueous solution of NaOH is 1.28 g/. The molality of the solution is:
[molecular mass of NaOH = 40 g mol-1]
| 1. | 1.20 m | 2. | 1.56 m |
| 3. | 1.67 m | 4. | 1.32 m |
When 7.3 g of magnesium bicarbonate (Mg(HCO3)2) is decomposed by heating, how much carbon dioxide gas (in mL) is released at STP?
1. 1000 mL
2. 1120 mL
3. 2230 mL
4. 3240 mL
| 1. | 40 mol | 2. | 10 mol |
| 3. | 20 mol | 4. | 30 mol |
1. 0.01 M
2. 0.001 M
3. 0.1 M
4. 0.02 M
1. 90.0 g conc. HNO3
2. 70.0 g conc. HNO3
3. 54.0 g conc. HNO3
4. 45.0 g conc. HNO3
When \(1.0\text{ g}\) of magnesium (\(\text{Mg}\)) is reacted with \(0.56\text{ g}\) of oxygen (\(\text{O}_2\)) in a closed container, determine the reactant left in excess and calculate the mass of the excess reactant remaining after the reaction is complete: (At. wt. Mg = 24; O = 16)
| 1. | Mg, 0.16 g | 2. | , 0.16 g |
| 3. | Mg, 0.44 g | 4. | , 0.28 g |
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