1.Which of following lists contain only elements

a. air water oxygen
b. hydrogen oxygen brass
c. Air water fire earth
d. Calcium sulphur carbon

2. What is the formula mass of CuSO4.5H2O

a. 159.5
b. 185.5
c. 249.5
d. 149.5

3. A compound with chemical formula Na2CX3 has formula mass 106amu. Atomic mass of element X is

a. 106
b. 23
c. 12
d. 16

4. How many moles of molecules of are there in 16g oxygen

a. 1
b. 0.5
c. 0.1
d.0.05

5. What is the mass of 5 moles of hydrogen gas

a. 8.064g
b. 4.032 g
c. 10g
d.1.008g

6. What is the mass of C present in 44g of carbon dioxide

a. 12g
b. 6g
c. 24g
d.44g

7. The electronic configuration of an element is 1s²2s².An atom of this element will form an ion that will have a charge of

a. +2
b. -2
c. +3
d.-1

8. Which term is same for one mole of oxygen and one mole of water

a. volume
b. mass
c. atoms
d.molecules

10. If one mole of carbon contains x atoms.what is the number of atoms contained in 12g of Mg

a. x
b. 0.5x
c. 2x
d.1.5x