Chemistry MCQ'S 3

(1) The number of Significant figures in 5.23*10^23 are 
(a)2 
(b)3 
(c)4 
(d)5
ANSWER: (b)

(2) What would be the decimal equivalent of 1/60 in 3 significant figures 
(a)0.0156 
(b)0.016666 
(c)0.0166 
(d)1.7*10^2
ANSWER: (c)

(3) Any charged particle is called as 
(a)Atom
(b)Ion
(c)Both
(d)N.O.T
ANSWER: (b)

(4) The formula which gives the actual number of atoms is called
(a)Empirical formula 
(b)Molecular formula 
(c)Unit formula 
(d) Structural formula 
ANSWER: (b)

(5) A compound is denoted by _______ mass.
(a)Molecular (b)Atomic (c) Formula (d)Ionic
ANSWER: (c)

(6) 50 g of H2O will possess ______ no: of moles.
(a)2.9 
(b)2.8 
(c)2.7 
(d) 2.6
ANSWER: (c)

(7) 88 g of CO2 contains ______ no: of molecules.
(a)6.02*10^23
(b)12.04*10^23 
(c)6.02*10^11
(d)N.O.T
ANSWER: (b)

(8) When atomic , molecular and formula masses are expressed in grams then they are called as,
(a)Mole fraction 
(b)Mole 
(c) Mass number 
(d) ALL
ANSWER: (b)

(9) 18.06*10^23 atoms of O2 possess ______ grams of mass.
(a)32 g
(b)64 g
(c)96 g
(d)128 g
ANSWER: (c)

(10) Sum of the atomic masses of all atoms present in a compound is called.
(a)Atomic mass 
(b)Formula mass 
(c)Empirical mass
(d)N.O.T
ANSWER: (b)