Chemistry Mcqs

1. Chemistry is the branch of science which deals with the.

A. Properties of matter 

B. Compostion of matter 

C. Struture of matter 

D. All of these 

2. The reliable digits in a number that are known with certainty are called. 

A. Significant figures 

B. Exponential numbers 

C. Avogadro,s numbers 

D. Constant number 

3. The last digit of a no. Generally considered uncertain by 

A. ±0.001

B. ±0.01

C. ±0.1

D  ±1

4. 400.8 has……. Significant figures 

A. Two

B.three

C.four 

D. one 

5. 5.00000 ……. has significant figures 

A. ONE 

B. THREE

C. FIVE 

D ONE 

6. 20600…… has significant figures 

A. ONE 

B.THREE 

C. FIVE 

D. ONE 

7. 5008.600 has …… significant figures 

A. ONE 

B.FOUR

C. FIVE 

D.SIX 

8.0.00023 has…… significant figures 

A.TWO

B. THREE

C.FIVE 

D. ONE 

9. 4239 has …… significant figures 

A. ONE 

B. TWO

C. THREE

D. FOUR 

10.One atomic mass unit (amu) is equal to the one twelth the mass of 

A. carbon 12atom 

B. carbon 13atom

C. carbon 14atom 

D.all of these 

11. the sum of the atomic masses of the atoms of all the elements in a molecules is called.

A. atomic mass

B. molecular mass 

C.Formula mass 

D.formula weight 

12. A fromula which shows the simplest ratio of atoms present in a compound is called’

A. molecular mass 

B. empirical fromula 

C. both a and b 

D. no any 

13. A fromula  which shows the relative and actual number of atoms perenst in a moleculs of the compound is called as. 

A.  Empirical fromula 

B. Molecular fromula 

C.Both A and B 

D. No any