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 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)
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 |
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
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 |