NTSE Chemistry Mole Concept MCQs

Question: The total number of protons, electrons and neutrons in 12 g of

   is -  

• a) 1.084 × 10²⁵          
• b) 6.022 × 10²³         
• c) 6.022 × 10²²           
• d) 18

Answer: 1.084 × 10²⁵             

Question: Which of the following sample contains the maximum number of atoms -

• a) 1 mg of C4H₁₀        
• b) 1 mg of N2          
• c) 1 mg of Na
• d) 1 mL of water

Answer: 1 mL of water

Question: The hydrated salt, Na2SO4. nH2O undergoes 55.9% loss in weight on heating and becomes anhydrous. The value of n will be -

• a) 5
• b) 3
• c) 7
• d) 10

Answer: 10

Question: The hemoglobin from the red blood corpuscles of most mammals contains approximately 0.33% of iron by weight. The molecular weight of hemoglobin is 67,200. The number of iron atoms in each molecule of hemoglobin is (Atomic weight of iron =56) 

• a) 2
• b) 3
• c) 4
• d) 5

Answer: 4

Question: How many atoms are contained in a mole of Ca(OH)2 - 

• a) 30 × 6.02 × 10²³ atoms/mol                       
• b) 5 × 6.02 × 10²³ atoms/mol
• c) 6 × 6.02 × 10²³ atoms/mol                          
• d) None of these

Answer: 5 × 6.02 × 10²³ atoms/mol

Question: Number of mole of 1 m3 gas at NTP are - 

• a) 44.6
• b) 40.6
• c) 42.6
• d) 48.6

Answer: 44.6

Question: Insulin contains 3.4% sulphur. The minimum molecular weight of insulin is -

• a) 941.176 u
• b) 944 u
• c) 945.27 u
• d) None of these

Answer: 941.176 u

Question: 2.76 g of silver carbonate of being strongly heated yields a residue weighing -

• a) 2.16 g                 
• b) 2.48 g
• c) 2.32 g
• d) 2.64 g

Answer: 2.16 g                 

Question: Rakes needs 1.71 g of sugar (C₁₂H₂₂O₁₁) to sweeten his tea. What would be the number of carbon atoms present in his tea ? 

• a) 3.6 × 10²²         
• b) 7.2 × 10²¹                 
• c) 0.05 × 10²³             
• d) 6.6 × 10²²

Answer: 3.6 × 10²²             

Question: The total number AIF3 molecule in a sample of AIF3 containing 3.01 × 10²³ ions of F- is -

• a) 9.0 × 10²⁴              
• b) 3.0 × 10²⁴               
• c) 7.5 × 10²³               
• d) 10²³

Answer: 10²³

Question: Volume of the 10 g of gas X is 5.6 litre at NTP. What will be the molecular weight of X ?

• a) 40
• b) 50
• c) 60
• d) 20

Answer: 40

Question: The number of molecules in one mole atoms are -

• a) 6.02 × 10²³ 
• b) 6.02 × 10^-23   
• c) 12.04 × 10²³ 
• d) 3.02 × 10^-23

Answer: 6.02 × 10²³ 

Question: Number of moles of NaOH required to neutralize 1 mole of H2SO4 will be -

• a) 1
• b) 2
• c) 3
• d) 5

Answer: 2

Question: Number of molecules present in 0.18 g H2O are - 

• a) 0.18 × 6.023 × 10²³
• b) 18 × 6.023 × 10²³  
• c) 6.023 × 10²³  
• d) 6.023 × 10²¹

Answer: 6.023 × 10²¹

Question: A piece of sodium weight 0.023 g. The number of atoms present in it are -

• a) 6.023 × 10²⁰   
• b) 60.23 × 10²²      
• c) 6.023 × 10²¹           
• d) 6.023 × 10¹⁹

Answer: 6.023 × 10²⁰   

Question: Number of a atoms of sulphur present in 80.25 g of sulphur is - (At. wt. of S = 32)

• a) 32
• b) 5
• c) 10
• d) 2.5

Answer: 2.5

Question: The number of molecules in one litre of water is equal to -

• a) 18 × 6.023 × 10²³
• b)

  

• c) 55.5 × 6.023 × 10²³  
• d) None of these

Answer: 55.5 × 6.023 × 10²³  

Question: Which of the following is not isoelectronic with O^2- ?          

• a) Na+   
• b) Ne
• c) N^3-   
• d) All are isoelectronic

Answer: All are isoelectronic

Question: What are the products of electrolysis of one mole of pure distilled water ?

• a) 2 g of H2 gas and 16 g of O2 gas are produces.
• b) 8 g of H2 gas and 8 g of O2 gas are produces.
• c) 4 g of H2 gas and 32 g of O2 gas are produced.
• d) None of these

Answer: None of these

Question: Amount of BaSO4 formed on mixing the aqueous solutions of 2.08 gm BaCI2 and excess of dil. H2SO4 is -

 [atomic weights - Ba = 137, cl = 35.5,s S = 32, O = 16].

• a) 2.33 g
• b) 2.08 g
• c) 1.04 g
• d) 1.165 g

Answer: 2.33 g

Question: ‘X’ g of sulphur has as many atoms as in 3 g of carbon. The value of ‘X’ is -

• a) 4
• b) 8
• c) 16
• d) 32

Answer: 8

Question: The number of gram molecules of oxygen in 6.02 × 10²⁴ carbon monoxide molecules is -           

• a) 10.0 gram molecules
• b) 5.0 gram molecules
• c) 1.0 gram molecules
• d) 0.5 gram molecules

Answer: 10.0 gram molecules

Question: What will be the volume in litres of 20 g of hydrogen gas at STP ?

• a) 22.4 litres
• b) 2.24 litres
• c) 224 litres
• d) 0.224 litres

Answer: 224 litres

Question: The number of molecules in 11.2 litre of CO2 at NTP will be-         

• a) 6.023 × 10²³  
• b) 2.505 × 10²³        
• c) 6.023 × 10²³            
• d) None

Answer: 2.505 × 10²³        

Question: No. of molecules present is 8g of O2 are -

• a) 1.505 × 10²³          
• b) 2.505 × 10²³         
• c) 6.023 × 10²³            
• d) None

Answer: 1.505 × 10²³          

Question: Which one of the following statements would be incorrect to use ?

• a) A mole of an element
• b) A mole of a compound
• c) An atom of an element
• d) An atom of a compound.

Answer: An atom of a compound.

Question: The largest number of molecules among the following is -

• a) 28 g of CO
• b) 46 g of C2H5OH 
• c) 36 g of H2O  
• d) 54 g of N2O5 

Answer: 36 g of H2O  

Question: Which of the following has smallest mass ?

• a) 6.022 × 10²³ atoms of He    
• b) 1 atom of He
• c) 1 mole atoms of He
• d) All have equal mass

Answer: 1 atom of He

Question: What is the weight of solute present in 2 litres of 0.6 M Na2CO3 ?

• a) 127.2 g
• b) 106 g
• c) 212 g
• d) 53 g

Answer: 127.2 g

Question: How many atoms are present in 2.50 mol of copper metal ?

• a) 1.5 × 10²³            
• b) 4.5 × 10²⁴ atoms     
• c) 1.5 × 10²⁴ atoms     
• d) 4.5 × 10²³ atoms

Answer: 1.5 × 10²⁴ atoms