Some Basic Concept of Chemistry

Some Basic Concept of Chemistry
Class:XI / Unit:1

1. Elements X and Y combine to form two compounds XY and X₂Y. Find the atomic weight of X and Y, if the weight of 0.1 moles of XY is 10g and 0.05 moles of X₂Y is 9gm

30, 20
80, 20
20, 30
60, 40

2. The number of atoms present in 0.1 moles of a triatomic gas is

1.806 × 10²²
1.806 × 10²³
6.026 x 10²²
3.600 × 10²³

3. Find the volume of O₂ required to burn 1 L of propane completely, measured at 0℃ temperature and 1 atm pressure

5L
6L
7L
10L

4. Pressure has the same dimension as

force per unit volume
energy
energy per unit volume
force

5. A container has an equal mass of H₂, O₂ and CH₄ at 27℃, the ratio of their volume is

8:1:2
8:16:1
16:1:2
16:8:1

6. 10 g of hydrogen and 64 g of oxygen were filled in a steel vessel and exploded. Amount of water produced in this reaction will be

1 mol
2 mol
3 mol
4 mol

7. The number of moles of KMnO₄ that will be needed to react with one mole of sulphite ion in acidic solution is:

2/5
3/5
4/5
1

8. What amount of dioxygen (in gram) contains 1.8 × 10²² molecules?

9.600
96.00
0.960
0.0960

9. The ratio of masses of oxygen and nitrogen in a particular gaseous mixture is 1 : 4. The ratio of number of their molecule is

7 : 32
1 : 4
3 : 16
1 : 8

10. If Avogadro number NA, is changed from 6.022 × 10²³ mol^–1 to 6.022 × 10²⁰ mol^–1, this would change

The ratio of chemical species to each other in a balanced equation
The ratio of elements to each other in a compound
The definition of mass in units of grams
The mass of one mole of carbon