Q. No.Which of the following contains the maximum number of atoms ?
1.
1 g of Mg(s)
2.
1 g of O2 (g)
3.
1 g of Li(s)
4.
1 g of Ag(s)
An oxide of iron contains 69.9% iron and 30.1% oxygen by mass. What is its empirical formula?
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 | (i). | mol kg–1 |
| B. | Molality | (ii). | mol L–1 |
| C. | Pressure | (iii). | Candella |
| D. | Luminous intensity | (iv). | Pascal |
Codes:
| A | B | C | D | |
| 1. | (i) | (iv) | (ii) | (iii) |
| 2. | (ii) | (i) | (iv) | (iii) |
| 3. | (i) | (iv) | (iii) | (ii) |
| 4. | (iv) | (i) | (iii) | (ii) |
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 g mol-1]
| 1. | 1.20 m | 2. | 1.56 m |
| 3. | 1.67 m | 4. | 1.32 m |
Percentage of C, H & N in 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.
How many significant figures are present in the following numbers?
| (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:
\(CaCO_3 (s)\ + \ HCl (aq)\ \rightarrow CaCl_2(aq)\ + CO_2(g)\ \\~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~+ H_2O(l)\)
1. 0.36 g
2. 0.09 g
3. 0.96 g
4. 0.66 g
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 |
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