Q. No.The number of significant figures in the numbers 5005, 500.0, and 126,000 are, respectively:
1. 2, 4, and 3
2. 4, 1, and 3
3. 4, 4, and 6
4. 4, 4, and 3
Which of the following correctly represents 234,000 and 6.0012 in scientific notation?
| 1. | \(2.34 \times 10^{-9} \text { and } 6 \times 10^3\) |
| 2. | \(0.234 \times 10^{-6} \text { and } 60012 \times 10^{-9}\) |
| 3. | \(2.34 \times 10^{-9} \text { and } 6.0012 \times 10^{-9}\) |
| 4. | \(2.34 \times 10^5 \text { and } 6.0012 \times 10^0\) |
| List-I | List-II | ||
| a. | Micro | i. | m |
| b. | Mega | ii. | m |
| c. | Giga | iii. | m |
| d. | Femto | iv. | m |
| a | b | c | d | |
| 1. | i | iv | iii | ii |
| 2. | iii | iv | ii | i |
| 3. | ii | iii | iv | i |
| 4. | i | iii | iv | ii |
How many grams of HCl are required to react with 5.0 g of manganese dioxide in the reaction provided?
\(4 \mathrm{HCl}_{(\mathrm{aq})}+\mathrm{MnO}_{2(\mathrm{~s})} \rightarrow 2 \mathrm{H}_2 \mathrm{O}_{(\mathrm{l})}+\mathrm{MnCl}_{2(\mathrm{aq})}+\mathrm{Cl}_{2(\mathrm{~g})}\)
1. 4.8 g
2. 6.4 g
3. 2.8 g
4. 8.4 g
The molar mass of naturally occurring Argon isotopes is:
| Isotope | Isotopic molar mass | Abundance |
| 36-Ar | 35.96755 g mol–1 | 0.337% |
| 38-Ar | 37.96272 g mol–1 | 0.063% |
| 40-Ar | 39.9624 g mol–1 | 99.600% |
| 1. | 49.99947 g mol-1 | 2. | 39.99947 g mol-1 |
| 3. | 35.59947 g mol-1 | 4. | 45.59947 g mol-1 |
If 10 volumes of H₂ react completely with 5 volumes of O₂, what volume of water vapor will be produced under the same conditions of temperature and pressure?
1. Nine (9)
2. Eight (8)
3. Ten (10)
4. Eleven (11)
For the reaction:
A + B₂ → AB₂
Which of the following cases represent situations in which A acts as the limiting reagent?
| i. | 300 atoms of A reacts with 200 molecules of B |
| ii. | 2 moles A reacts with 3 moles B2 |
| iii. | 100 atoms of A reacts with 100 molecules of B |
| iv. | 5 moles A reacts with 2.5 moles B |
| v. | 2.5 moles A reacts with 5 moles B2 |
Choose the correct option:
| 1. | (i), (ii) | 2. | (i), (ii), (v) |
| 3. | (ii), (v) | 4. | All |
Calculate the mass percentages of sodium (Na), sulfur (S), and oxygen (O), respectively, in sodium sulphate (Na₂SO₄):
1. 32.4%, 45.05% and 22.6%
2. 22.6%, 45.05% and 32.4%
3. 32.4%, 22.6% and 45.05%
4. 45.05%, 32.4% and 22.6%
| Assertion (A): | When 4 moles of H2 reacts with 2 moles of O2, then 4 moles of water are formed. |
| Reason (R): | O2 will act as a limiting reagent. |
| 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. | Both (A) and (R) are False. |
| Assertion (A): | The number of molecules in 2 moles of NH3 is equal to the number of molecules in 4 moles of CH4. |
| Reason (R): | Both are chemically similar species. |
| 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. | Both (A) and (R) are False. |
© 2026 GoodEd Technologies Pvt. Ltd.