Mole Concept Quiz | Mole Concept Objective Type Questions and Answers

Questions
21 What is a mole?
A A mole is found in a certain number of cm3 of one substance or another
B A mole is the sum of atomic weights
C A mole is the number of molecules in one gram of a substance
D None of the mentioned

Answer: None of the mentioned
22 A mixture of gases contains H2 and O2 gases in the ratio of 1:4 (w/w). What is the molar ratio of the two gases in the mixture?
A 1:4
B 4:1
C 16:1
D 2:1

Answer: 4:1
23 What is the mass of precipitate formed when 50 mL of 16.9% solution of AgNO3 is mixed with 50 mL of 5.8% NaCl solution? (Ag = 107.8, N = 14, O = 16, Na= 23,Cl=35.5)
A 28 g
B 3.5 g
C 7 g
D 14 g

Answer: 7 g
24 What is the mole fraction of the solute in a 1.00 m aqueous solution?
A 0.177
B 1.770
C 0.0354
D 0.0177

Answer: 0.0177
25 6.02 x 1020 molecules of urea are present in 100 mL of its solution. The concentration of the solution is
A 0.02 M
B 0.01 M
C 0.001 M
D 0.1 M

Answer: 0.01 M
26 The number of atoms in 0.1 mole of a triatomic gas is (NA=6.02 x1023mol-1)
A 6.026 x 1022
B 1.806x1023
C 3.600 x 1023
D 1.800 x 1022

Answer: 1.806x1023
27 How many moles of lead (II) chloride will be formed from a reaction between 6.5g of PbO and 3.2g of HCl?
A 0.044
B 0.333
C 0.011
D 0.029

Answer: 0.029
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