Q. No.The number of gram molecules of oxygen in 6.02 × 1024 CO molecules are:
1. 10 g molecules
2. 5 g molecules
3. 1 g molecules
4. 0.5 g molecules
What is the correct ascending order of masses for the following (I to IV)?
(Atomic mass : N=14, O=16 Cu = 63)
I. 1 molecule of oxygen
II. 1 atom of nitrogen
III. 1 x 10-10g molecule-weight of oxygen
IV. 1 x 10-10g atom-weight of copper
Codes
1. II < I < III < IV
2. IV < III < II < I
3. II < III < I < IV
4. III < IV < I < II
A sample of CaCO3 is 50% pure. On heating 1.12 litres of CO2 (at STP) is obtained. The weight of residues left (assuming non-volatile impurity) is:
(Ca = 40, C= 12, O=16)
| 1. | 7.8 g | 2. | 5 g |
| 3. | 3.8 g | 4. | 2.8 g |
The mole fraction of the solute in a 1.00 molal aqueous solution is:
| 1. | 0.00177 | 2. | 0.0344 |
| 3. | 0.0177 | 4. | 0.1770 |
A mixture of and gas "Y" (mol. wt. 80) in the mole ratio a : b has a mean molecular weight of 40. What would be the mean molecular weight, if the gases are mixed in the ratio b : a under identical conditions? (assume that these gases do not react)
| 1. | 40 | 2. | 48 |
| 3. | 62 | 4. | 72 |
The vapour density of a mixture containing \(NO_{2}\) and \(N_{2} O_{4}\) is 38.3. The mole of \(NO_{2}\) in a 100 g mixture is:
[Vapour density = (Molar mass / 2)]
1. 0.437
2. 0.347
3. 0.557
4. 0.663
The average molar mass of the mixture of and present in the mole ratio of a:b is
20 g mol-1. When the mole ratio is reversed, the molar mass of the mixture will be:
| 1. | 24 gram | 2. | 42 gram |
| 3. | 20 gram | 4. | 15 gram |
At constant T and P, 5.0 L of SO2 is reacted with 3.0 L of O2 according to the following equation:
2SO2(g) + O2(g) → 2SO3(g)
The volume of the remaining reaction mixture at the completion of the reaction will be:
1. 0.5 L
2. 8.0 L
3. 5.5 L
4. 5 L
| Assertion (A): | 1 g O2 and 1 g O3 have an equal number of oxygen atoms. |
| Reason (R): | O2 and O3 have different molar masses. |
| 1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
| 3. | (A) is True but (R) is False. |
| 4. | (A) is False but (R) is True. |
Given below are two statements:
| Assertion (A): | One atomic mass unit is defined as one-twelfth of the mass of one carbon-12 atom. |
| Reason (R): | The carbon-12 isotope is the most abundant isotope of carbon and has been chosen as the standard. |
| 1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
| 3. | (A) is True but (R) is False. |
| 4. | (A) is False but (R) is True. |
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