- 1(current)
Q. No.Two students performed the same experiment separately, and each of them recorded two readings of mass, which are given below. The correct reading of mass is 3.0 g. On the basis of the given data, mark the correct option out of the following statements.
| Students | Readings | |
| (i) | (ii) | |
| A | 3.01 | 2.99 |
| B | 3.05 | 2.95 |
| 1. | The results of both the students' are neither accurate nor precise. |
| 2. | The results of student A are both precise and accurate. |
| 3. | Student B's results are neither precise nor accurate. |
| 4. | The results of student B are both precise and accurate. |
A reading on Fahrenheit scale is . The same reading on celsius scale will be :
| 1. | 40°C | 2. | 94°C |
| 3. | 93°C | 4. | 30°C |
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 can not 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. |
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 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 significant figure for 0.200 is 3, whereas the significant figure for 200 is 1. |
| Reason (R): | Zero at the end or right of a number is significant, provided it is not on the right side of the decimal point. |
| 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. |
One of the statements of Dalton's atomic theory is given below:
"Compounds are formed when atoms of different elements combine in a fixed ratio"
Which of the following laws is not related to this statement?
(a) Law of conservation of mass
(b) Law of definite proportions
(c) Law of multiple proportions
(d) Avogadro law
1. (a), (d)
2. (b), (c)
3. (c), (d)
4. (b), (d)
- 1(current)
Q. No.
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