Q. No.The highest number of atoms is present in -
1. 52 moles of Ar
2. 52 u of He
3. 52 g of He.
4. All of the above have the same number of atoms
Burning a small sample of welding gas (constituted of C and H only) in oxygen gives 3.38 g carbon dioxide, 0.690 g of water, and no other products. A volume of 10.0 L (measured at STP) of this welding gas is found to weigh 11.6 g. Molecular formula of welding gas would be:
1. C2H2
2. C2H6
3. CH
4. C2H4
The mass of CaCO3 required to react completely with 25 mL of 0.75 M HCl according to the given reaction would be:
\(CaCO_3 (s)\ + \ HCl (aq)\ \rightarrow CaCl_2(aq)\ + CO_2(g)\ \\~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~+ H_2O(l)\)
1. 0.36 g
2. 0.09 g
3. 0.96 g
4. 0.66 g
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
One mole of oxygen gas at STP is equal to:
| (a) | 6 .022× 1023 molecules of oxygen |
| (b) | 6.022 × 1023 atoms of oxygen |
| (c) | 16 g of oxygen molecule |
| (d) | 32 g of oxygen |
Choose the correct answer from the option given below:
1. (a) and (b)2. (a) and (c)
3. (a) and (d)
4. (c) and (d)
Sulphuric acid reacts with sodium hydroxide as follows
When 1L of 0.1 M sulphuric acid solution is allowed to react with 1 L of 0.1 M sodium hydroxide solution, the amount of sodium sulphate formed and its molarity in the solution obtained are respectively-
| 1. | 0.1 M, 7.10 g | 2. | 7.10 g, 0.025 M |
| 3. | 0.025 M, 3.55 g | 4. | 3.55 g, 0.25 M |
Which of the following pairs have the same number of atoms?
| (a) | 16 g of O2(g) and 4 g of H2(g) |
| (b) | 16 g of O2 and 44 g of CO2 |
| (c) | 28 g of N2 and 32 g of O2 |
| (d) | 12 g of C(s) and 23 g of Na(s) |
1. (a), (b)
2. (b), (c)
3. (c), (d)
4. (b), (d)
Which of the following solutions have the same concentration?
| 1. | 20 g of NaOH in 200 mL of solution |
| 2. | 0.5 mol of KCl in 200 mL of solution |
| 3. | 40 g of NaOH in 100 mL of solution |
| 4. | 20 g of KOH in 200 mL of solution |
1. (a), (b)
2. (b), (c)
3. (c), (d)
4. (b), (d)
16 g of oxygen has the same number of molecules as in:
(a) 16 g of CO
(b) 28 g of N2
(c) 14 g of N2
(d) 1.0 g of H2
1. (a), (b)
2. (b), (c)
3. (c), (d)
4. (b), (d)
Unitless terms among the following are:
| (a) | Molality | (b) | Molarity |
| (c) | Mole fraction | (d) | Mass percent |
| 1. | (a), (b) | 2. | (b), (c) |
| 3. | (c), (d) | 4. | (b), (d) |
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