The maximum number of atoms is present in which of the following -
1. 1 g of Mg(s)
2. 1 g of O2 (g)
3. 1 g of Li(s)
4. 1 g of Ag(s)
The empirical formula of an oxide of iron, which has 69.9% iron and 30.1% oxygen by mass is -
1. FeO
2. Fe2O3
3. Fe3O4
4. Fe3O2
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. | \(46.80~\mathrm{g}\) |
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 |
The density of a 2 M aqueous solution of NaOH is 1.28 g/. The molality of the solution is:
[molecular mass of NaOH = 40 ]
1. | 1.20 m | 2. | 1.56 m |
3. | 1.67 m | 4. | 1.32 m |
Percentage of C, H & N of a compound is given as follows:
C=40%, H=13.33%, N=46.67%
The empirical formula of the compound will be:
1.
2.
3.
4.
The number of significant figures in the following numbers is:
(I). | 161 cm |
(II). | 0.0161 |
(III). | 1.61 |
1. 3, 3, 3
2. 3, 4, 3
3. 3, 2, 3
4. 3, 4, 4
The mass of CaCO3 required to react completely with 25 mL of 0.75 M HCl according to the given reaction would be:
CaCO3(s) + HCl(aq) ➡ CaCl2(aq) + CO2(g) + H2O(l)
1. 0.36 g
2. 0.09 g
3. 0.96 g
4. 0.66 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