Question

11. The molarity of a solution containing 5g of NaOH in 250cm solution is
a) 0.5
b) 0.1
c)2
d) 1
12. 1.5 moles of O2 combine with Mg to form the oxide Mgo. The mass of Mg that has combined
is (Mg = 24)
a) 729
b) 369
c) 489
d) 24g
13. The total number of electrons in 180 ml of water (density = 1 g mil) is
a) 6.02 x 1023
b) 6.02 x 1025
c) 6.02 x 1024 d) 6.02 x 18 x 1023
14. 30g of magnesium and 30g of oxygen are reacted and the residual mixture contains
a) 60g of magnesium oxide only
b) 40g of magnesium oxide and 20g of oxygen
c) 45g of magnesium oxide and 15g of oxygen
d) 50g of magnesium oxide and 10g of oxygen
15. Which of the following contains same number of molecules as found in 11 g of CO2?
a) 14 g of N2
b) 24 g of O2
c) 4 g of methane
d) 14 g of carbon monoxide
16. Mass of 0.1 mol of methane is
a) 1.6 g
b) 0.19
c) 1.0 9
d) 16 9
17. The number of water molecules present in a drop of water weighing 0.018 gm is
1) 6.022 x 1026
2) 6.022 x 1023
3) 6.022 x 1019
4) 6.022 x 1020
18. What volume of CO2 will be liberated at NTP, if 12 g of carbon is burnt in excess of oxygen?
a) 11.2 L
b) 22.4L
C) 2.24 L
d) 1.12 L
19. Empirical formula of a compound is CH2O and its molecular mass is 90, the molecular
formula of the compound is
1) C3H603
2) C2H4O2
3) C6H1206 4) CH20
20. The mass of 227 cm of NH3 gas at STP is
1) 1.69
2) 0.850 g
3) 8.500 g
4) 0.16 g

Answer 1

Explanation:

11 11 is equal to a 0.5

12 is equal to c 489

13 is equal to D 6.02 into 18.10 to the power 23

14 is equal to D 50 gram of magnesium oxide and 10 gram of oxygen

15 is equal to b 24 gram of O2

16 is equal to be 0.1 ram

18 is equal to a 11.2

19 is equal to AC

23 call to c 8.500 DRAM