Question

PART -T! CHEMISTRY
A compound has the molecular formula X,OcIf 10 g of X,
(A) 32 amu
has 5.72 g of X, then atomic mass of X is:
(B) 37 amu
(C) 42 amu
(D) 98 amu
Carbon occur in nature as a mixture of C-12 and C-13. Average atomic mass of carbon is 12.011 what is the
% abundance of C-12 in nature ?
(A) 98.9%
(B) 60.9%
(C)32.9%
(D) 1.4%
3
One atom of an element x weigh 6.643 x 10-23g Number of moles of atom in 20 kg is
(A) 4
(B) 40
(C) 100
(D) 500
What percentage of oxygen is present in the compound Caco, 3Ca,(PO.), ?
(A) 23.3%
(B) 45.36%
(C)41.94%
(D) 17.08%
Number of electrons in 1.8 mL of H2O(l)
(A) 6.02 x 1023 (B) 3.011x 102 (C) 0.6022x10 (D) 60.22x10-
Equal masses of oxygen, hydrogen and methane are taken in a container in identical conditions. Find the ratio
of their moles.
(A) 1:16:2
(B) 1:16:1
(C) 16:1:1
(D) 16:2:1
3
.
Which of the following contains the same number of molecules ?
(A) 1g of O, 2g of So,
(B) 1g of Co, 1g of N O
(C) 112 ml of O, at STP, 224 ml of He at 0.5 atm and 273 K
(D) All of these
In a compound Carbon = 52.2%, Hydrogen = 13%, Oxygen = 34.8% are present and vapour density of the
compound is 46. Calculate molecular formula of the compound?
(A) C,H,O,
(B)C,H,O,
(C)CHO (D) CHO​

Answer 1

Answers:-

1) (A)

2) (D)

3) (C)

4) (A)

5) (B)

6) (A)

7) (D)

8) (B)