The mass percent of carbon in carbon dioxide is:
1. | 0.034% | 2. | 27.27% |
3. | 3.4% | 4. | 28.7% |
The empirical formula and molecular mass of a compound are and 180 g, respectively. The molecular formula of the compound is -
1. C9H18O9 | 2. CH2O |
3. C6H12O6 | 4. C2H4O2 |
If the density of the solution is 3.12 g ml-1, then what will be the mass of the 1.5 ml solution in two significant figures?
1. | \(4.4~\mathrm{g}\) | 2. | \(4680 \times 10^{3} ~\mathrm{g}\) |
3. | \(4.7~\mathrm{g}\) | 4. | \(46.80~\mathrm{g}\) |
The incorrect statement among the following is:
1. | A molecule of a compound has atoms of different elements. |
2. | A compound cannot be separated into its constituent elements by the physical method of separation. |
3. | A compound retains the physical properties of its constituent elements. |
4. | The ratio of atoms of different elements in a compound is fixed. |
Which of the following statements is correct about the reaction is given below?
1. | Total mass of iron and oxygen in reactants = total mass of iron and oxygen in product therefore it follows law of conservation of mass |
2. | Total mass of reactants = total mass of product, therefore, law of multiple proportions is followed |
3. | Amount of Fe2O3 can be increased by taking any one of the reactants (iron or oxygen) in excess |
4. | Amount of Fe2O3 produced will decrease if the amount of any one of the reactants (iron or oxygen) is taken in excess |
Identify the reaction that does not obey the law of conservation of mass from the provided options.
1.
2.
3.
4.
Which of the following statement indicates that the law of multiple proportions is being followed?
1. | A sample of carbon dioxide taken from any source will always have carbon and oxygen in the ratio of 1:2. |
2. | Carbon forms two oxides namely, CO2 and CO, where masses of oxygen that combine with a fixed mass of carbon are in the simple ratio of 2:1. |
3. | When magnesium burns in oxygen, the amount of magnesium used for the reaction is equal to the amount of magnesium formed in magnesium oxide. |
4. | At constant temperature and pressure, 200 mL of hydrogen will combine with 100 mL of oxygen to produce 200 mL of water vapour. |
Match the following:
COLUMN I | COLUMN II |
A. 88 g of CO2 | 1. 0.25 mol |
B. 6.022×1023 molecules of H2O | 2. 2 mol |
C. 5.6 L of O2 at STP | 3. 3 mol |
D. 96 g of O2 | 4. 1 mol |
A | B | C | D | |
1. | 2 | 4 | 1 | 3 |
2. | 1 | 2 | 3 | 4 |
3. | 1 | 4 | 3 | 2 |
4. | 4 | 1 | 3 | 2 |
Match the following physical quantities with units.
Physical quantity | Unit |
A. Molarity | 1. mol kg-1 |
B. Molality | 2. mol L-1 |
C. Pressure | 3. Candela |
D. Luminous intensity | 4. Pascal |
Codes
A | B | C | D | |
1. | 1 | 4 | 2 | 3 |
2. | 2 | 1 | 4 | 3 |
3. | 1 | 4 | 3 | 2 |
4. | 4 | 1 | 3 | 2 |
Assertion (A): | The empirical mass of ethene is half of its molecular mass. |
Reason (R): | The empirical formula represents the simplest whole-number ratio of the various atoms present in a compound. |
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. |