Suppose the elements X and Y combine to form two compounds XY2 and X3Y2. If 0.1 mole of XY2 weighs 10 g and 0.05 mole of X3Y2 weighs 9 g, the atomic weight of X and Y respectively, will be:
1. | 40, 30 | 2. | 60, 40 |
3. | 20, 30 | 4. | 30, 20 |
Which of the following is dependent on temperature?
1. | Molarity | 2. | Mole fraction |
3. | Weight percentage | 4. | Molality |
A mixture of 2.3 g formic acid and 4.5 g oxalic acid is treated with conc. . The evolved gaseous mixture is passed through KOH pellets.
Weight (in g) of the remaining product at STP will be:
1. 1.4
2. 3.0
3. 2.8
4. 4.4
20.0 g of a magnesium carbonate sample decomposes on heating to give carbon dioxide and 8.0 g of magnesium oxide.
The percentage purity of magnesium carbonate in the sample will be:
(Atomic weight of Mg=24)
1. | 75 | 2. | 96 |
3. | 60 | 4. | 84 |
A mixture of gases contains H2 and O2 gases in the ratio of 1 : 4 (w/w). The molar ratio of the two gases in the mixture will be:
1. | 1:4 | 2. | 4:1 |
3. | 16:1 | 4. | 2:1 |
25.3 g of sodium carbonate, Na2CO3, is dissolved in enough water to make 250 mL of a solution. If sodium carbonate completely dissociates, the molar concentrations of sodium ion, Na+ and carbonate ion, are respectively:
(molar mass of Na2CO3 = 106g mol-1)
1. 0.955 M and 1.910 M
2. 1.910 M and 0.955 M
3. 1.90 M and 1.910 M
4. 0.477 M and 0.477 M
The volume occupied by one water molecule (density = 1 g cm-3) is:
1.
2.
3.
4.
The volume of oxygen gas (O2) needed to completely burn 1 L of propane gas (C3H8) (both O2 & propane measured at 0°C and 1 atm) will be:
1. 7 L
2. 6 L
3. 5 L
4. 10 L
An organic compound contains carbon, hydrogen, and oxygen. Its elemental analysis gave C, 38.71%, and H, 9.67%. The empirical formula of the compound would be:
1. | CH3O | 2. | CH2O |
3. | CHO | 4. | CH4O |