Question 1

Which of the following is incorrect empirical formula?

Accepted Answer

BaNO3

Question 2

How many elements are present in haemoglobin?

Accepted Answer

6 - Carbon , Hydrogen , Oxygen, nitrogen, sulphur, iron

Question 3

Di-isotopic element which have maximum number of neutrons?

Accepted Answer

Chlorine  - Cl have 18 neutrons while N has 7, O has 8 and S has 16.

Question 4

Total number of stoichiometric relationships?

Accepted Answer

16 - There are 16 stoichiometric relationships which include the relationships between moles, mass, volume and particles.

Question 5

100 moles of water contain:

Accepted Answer

1000 moles of electrons

Question 6

Maximum number of molecules are present in:

Accepted Answer

1.5 g of H2

Question 7

Absorption of CO2 in combustion analysis will be maximum when used:

Accepted Answer

50% KOH - 100% KOH is pure solid so it cannot be used in absorption. 50 KOH is used.

Question 8

A compound contains 50% of X and 50% of Y. Atomic mass of X=20 and of Y=30. Find the empirical formula?

Accepted Answer

X3Y2 - X:Y    50%/20 : 50%/30      1/2:1/3     3:2      so X3Y2

Question 9

A researcher had prepared a sample of 1-bromopropane from 10g of 1-propanol after purification he obtained 12g of the product. Percentage yield is:

Accepted Answer

58%

Question 10

Calculate number of gram atoms of carbon in a compound having 60% carbon.

Accepted Answer

5 - 60%/12 = 5

Question 11

0.36 moles of aluminium and oxygen react to produce alumina. Identify the limiting reactant.

Accepted Answer

Aluminium  - 4Al + 3O2 ------->    2Al2O3. aluminium is consumed earlier.

Question 12

If we consider 1/6th instead of 1/12th of carbon, the mass of water will be?

Accepted Answer

9 amu - Atomic mass / (1/6th of Carbon atom). = 18/(1/6×12) =9

WCW Chemistry Quiz by AH

2) How many elements are present in haemoglobin?