Which of the following contains the greatest number of nitrogen atoms ?
1. 500 ml of 2.0
2. One mole of
3. molecules of gas
4. 22.4 litres of gas at 0ºC and 1 atm.
A mixture of methane and ethene in the molar ratio of x : y has a mean molar mass of 20. What would be the mean molar mass. if the gases are mixed in the molar ratio of y : x?
(1) 22
(2) 24
(3) 20.8
(4) 19
Calculate number of electrons present in 9.5 g of :
1.
2.
3.
4.
The total no. of neutrons present in 54 mL are:
1.
2.
3.
4. none of these
The volume of a drop of water is 0.0018 mL then the number of water molecules present in two drop of water at room temperature is:
1.
2.
3.
4.
Which of the following combinations illustrates the law of reciprocal proportions?
1.
2.
3.
4.
Carbon and oxygen combine to form two oxides, carbon monoxide and carbon dioxide in which the ratio of the weights of carbon and oxygen is respectively 12 : 16 and 12 : 32. These figures illustrate the:
1. Law of multiple proportions
2. Law of reciprocal proportions
3. Law of conservation of mass
4. Law of constant proportions
The formula of an acid is The mass of 0.0242 moles of the acid is 1.657 g.
The atomic weight of X is:
1. | 35.5 | 2. | 28.1 |
3. | 128 | 4. | 19.0 |
A 6.85 g sample of the hydrates is dried in an oven to give 3.13 g of anhydrous . The value of x is -
(Atomic weights : Sr=87.60, O=16.0, H=1.0)
1. 8
2. 12
3. 10
4. 6
The sulphate of the metal M contains 9.87% of M. This sulphate is isomorphous with . The atomic weight of M is:
1. 40.3
2. 36.3
3. 24.3
4. 11.3