NEET Chemistry Some Basic Concepts Of Chemistry MCQs Set A

Question:  A sample of ammonium phosphate (NH ₄)₃ PO ₄ contains 3.18 moles of hydrogen atoms. The number of moles of oxygen atoms in the sample is

• a) 0.265
• b) 0.795
• c) 1.06
• d) 4.00

Answer: 1.06

Question: In which of the following numbers all zeros are significant?

• a) 0.0007
• b) 0.0070
• c) 70.000
• d) 0.700

Answer: 70.000

Question:  Two metallic oxides contain 27.6% and 30% oxygen respectively. If the formula of the first oxide is X₃O₄ , that of the second will be 

• a) XO
• b) XO₂
• c) X₂O₅
• d) X₂O₃

Answer:  X₂O₃

Question: Calculate the molality of solution containing 3 g glucose dissolved in 30 g of water. (molar mass of glucose = 180)

• a) 0.50 m
• b) 0.56 m
• c) 0.091 m
• d) 0.05 m

Answer: 0.56 m

Question:  An element, X has the following isotopic composition ²⁰⁰X : 90% ¹⁹⁹X : 8% ²⁰²X : 2.0%. The weighted average atomic mass of the naturally occurring element X is closest to

• a) 201 amu
• b) 202 amu
• c) 199 amu
• d) 200 amu

Answer: 200 amu

Question: Which has the maximum number of molecules among the following?

• a) 8 g H₂
• b) 64 g SO₂
• c) 44 g CO₂
• d) 48 g O₃

Answer:  8 g H₂

Question:  What volume of oxygen gas (O₂) measured at 0°C and 1 atm, is needed to burn completely 1 L of propane gas (C₃H₈) measured under the same conditions?

• a) 10 L
• b) 7 L
• c) 6 L
• d) 5 L

Answer: 5 L

Question:  Volume occupied by one molecule of water (density = 1 g cm^–3) is

• a) 5.5 × 10^–23 cm³ 
• b) 9.0 × 10^–23 cm³
• c) 6.023 × 10^–23 cm³
• d) 3.0 × 10^–23 cm³

Answer: 3.0 × 10^–23 cm³

Question:  The total number of electrons in 1.6 g of CH₄ to that in 1.8 g of H₂O

• a) Double
• b) Same
• c) Triple
• d) One fourth

Answer: Same

Question:  When x molecules are removed from 200 mg of N₂O, 2.89 × 10^–3 moles of N₂O are left. x will be

• a) 1020 molecules
• b) 1010 molecules
• c) 21 molecules
• d) 1021 molecules

Answer: 1021 molecules

Question: 4 g of hydrogen reacts with 20 g of oxygen to form water. The mass of water formed is

• a) 24 g
• b) 36 g
• c) 22.5 g
• d) 40 g

Answer: 22.5 g

Question: Which has maximum molecules?

• a) 7 g N₂O
• b) 20 g H₂
• c) 16 g NO₂
• d) 16 g SO₂

Answer: 20 g H₂

Question:  The number of molecules in 4.25 g of NH₃ is approximately 

• a) 4 × 10²³
• b) 1.5 × 20²³
• c) 1 × 10²³
• d) 6 × 10²³

Answer:  1.5 × 20²³

Question: The maximum number of molecules is present in

• a) 15 L of H₂ gas at STP
• b) 5 L of N₂ gas at STP
• c) 0.5 g of H₂ gas 
• d) 10 g of O₂ gas

Answer: 15 L of H₂ gas at STP

Question: The number of atoms in 0.1 mol of a tetraatomic gas is (N_A= 6.02 × 10²³ mol^–1)

• a) 2.4 × 10²²
• b) 6.026 × 10²²
• c) 2.4 × 10²³
• d) 3.600 × 10²³

Answer:  2.4 × 10²³

Question: How many grams of NaOH should be added to water to prepare 250 ml solution of 2 M NaOH?

• a) 9.6 × 10³ 
• b) 2.4 × 10³
• c) 20
• d) 24

Answer: 20

Question: Haemoglobin contains 0.334% of iron by weight. The molecular weight of haemoglobin is approximately 67200. The number of iron atoms (Atomic weight of Fe is 56) present in one molecule of haemoglobin is

• a) 4
• b) 6
• c) 3
• d) 2

Answer: 4

Question:  In the reaction,

when 1 mole of SO₂ and 1 mole of O₂ are made to react to completion

• a) All the oxygen will be consumed
• b) 1.0 mole of SO₃ will be produced
• c) 0.5 mole of SO₂ is remained 
• d) All of these

Answer:  1.0 mole of SO₃ will be produced

Question: If the weight of metal chloride is x gram containing y gram of metal, the equivalent weight of metal will be

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: 10 g of hydrogen and 64 g of oxygen were filled in a steel vessel and exploded. Amount of water produced in this reaction will be

• a) 1 mol
• b) 2 mol
• c) 3 mol
• d) 4 mol

Answer: 4 mol

More Questions........................................................

Question:  The total number of electrons in 4.2 g of N^3– ion is (N_A is the Avogadro’s number)

• a)  2.1 N_A
• b) 4.2 N_A
• c) 3 N_A
• d) 3.2 N_A

Answer:  3 N_A

Question: The number of mole of nitrogen in one litre of air containing 10% nitrogen by volume, under standard conditions, is

• a) 0.03 mole
• b) 2.10 moles
• c) 0.186 mole
• d) 4.46 × 10^–3 mole

Answer:  4.46 × 10^–3 mole

Question:  Liquid benzene (C₆H₆ ) burns in oxygen according to 

How many litres of O₂ at STP are needed to complete the combustion of 39 g of liquid benzene?

• a) 74 L
• b) 11.2 L
• c) 22.4 L
• d) 84 L

Answer: 84 L

Question:  1 mol of KClO₃ is thermally decomposed and excess of aluminium is burnt in the gaseous product. How many moles of Al₂O₃ are formed?

• a) 1
• b) 2
• c) 1.5
• d) 3

Answer: 1

Question:  The amount of zinc required to produce 1.12 ml of H₂ at STP on treatment with dilute HCl will be

• a) 65 g
• b) 0.065 g
• c) 32.5 × 10^–4 g 
• d) 6.5 g

Answer:  32.5 × 10^–4 g 

Question:  Volume of CO₂ obtained at STP by the complete decomposition of 9.85 g Na₂ CO₃ is

• a) 2.24 litre
• b) Zero litre
• c) 0.85 litre
• d) 0.56 litre

Answer: Zero litre

Question:  One litre of CO₂ is passed through red hot coke. The volume becomes 1.4 litres at same temperature and pressure. The composition of products is

• a) 0.8 litre of CO₂ and 0.6 litre of CO
• b) 0.7 litre of CO₂ and 0.7 litre of CO
• c) 0.6 litre of CO₂ and 0.8 litre of CO
• d) 0.4 litre of CO₂ and 1.0 litre of CO

Answer:  0.6 litre of CO₂ and 0.8 litre of CO

Question:  Suppose that A and B form the compounds B₂A₃ and B₂A. If 0.05 mole of B₂A₃ weighs 9 g and 0.1 mole of B₂ A weighs 10 g, the atomic weight of A and B respectively are

• a) 30 and 40
• b) 40 and 30
• c) 20 and 5
• d) 15 and 20

Answer: 40 and 30

Question:  When 100 ml of

is mixed with 500 ml of

NaOH then nature of resulting solution and normality of excess of reactant left is

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: Mole fraction of solvent in aqueous solution of NaOH having molality of 3 is

• a) 0.3
• b) 0.05
• c) 0.7
• d) 0.95

Answer: 0.95

Question:  Concentrated aqueous sulphuric acid is 98% H₂SO₄ by mass and has a density of 1.80 gmL^–1. Volume of acid required to make one litre of 0.1 M H₂SO₄ solution is

• a) 16.65 mL
• b) 22.20 mL
• c) 5.55 mL
• d) 11.10 mL

Answer: 5.55 mL

Question:   Number of significant figures in 6.62 × 10^–34.

• a) Two
• b) Three
• c) Four
• d) One

Answer: Three

Question:  Ammonia gas is passed into water, yielding a solution of density 0.93 g/cm³ and containing 18.6% NH₃ by weight. The mass of NH₃ per cc of the solution is

• a) 0.17 g/cm³ 
• b) 0.34 g/cm³
• c) 0.51 g/cm³
• d) 0.68 g/cm³

Answer:  0.17 g/cm³ 

Question:  A certain amount of a metal whose equivalent mass is 28 displaces 0.7 L of H₂ at S.T.P. from an acid hence mass of the element is

• a) 1.75 g
• b) 0.875 g
• c) 3.50 g
• d) 7.00 g

Answer: 1.75 g

Question: Number of Fe atoms in 100 g Haemoglobin if it contains 0.33% Fe. (Atomic mass of Fe = 56)

• a) 0.035 × 10²³ 
• b) 35
• c) 3.5 × 10²³ 
• d) 7 × 10⁸

Answer: 0.035 × 10²³ 

Question: An organic compound containing C and H gave the following analysis C = 40%, H = 6.7%. Its empirical formula would be

• a) CH₄
• b) CH₂O
• c) C₂H₄O₂
• d) C₂H₄

Answer:  CH₂O

Question:  The number of electrons in 1.6 g of CH₄ is approximately

• a) 25 × 10²⁴ 
• b) 1.5 × 10²⁴
• c) 6 × 10²³
• d) 3.0 × 10²⁴

Answer: 6 × 10²³

Question:  6.025 × 10²⁰ molecules of acetic acid are present in 500 ml of its solution. The concentration of solution is 

• a) 0.002 M
• b) 10.2 M
• c) 0.012 M
• d) 0.001 M

Answer: 0.002 M

Question:  How many litre of oxygen at STP is required to burn 60 g C₂H₆ ?

• a) 22.4 L
• b) 11.2 L
• c) 22.4 × 7 L
• d) 8.5 L

Answer: 22.4 × 7 L

Question: For the formation of 3.65 g of HCl gas, what volume of hydrogen gas and chlorine gas are required at NTP conditions?

• a) 1 L, 1 L
• b) 1.12 L, 2.24 L
• c) 3.65 L, 1.83 L
• d) 1.12 L, 1.12 L

Answer: 1.12 L, 1.12 L

Question:  A mixture of gases contains H₂and O₂ gases in the ratio of 1 : 4 (w/w). What is the molar ratio of the two gases in the mixture? 

• a) 2 : 1
• b) 1 : 4
• c) 4 : 1
• d) 16 : 1

Answer: 4 : 1

Question:  Specific volume of cylindrical virus particle is 6.02 × 10^–2 cc/gm whose radius and length are 7 Å and 10 Å respectively. If N_A= 6.02 × 10²³, find molecular weight of virus.

• a) 15.4 kg/mol 
• b) 1.54 × 10⁴ kg/mol
• c) 3.08 × 10⁴ kg/mol
• d) 3.08 × 10³ kg/mol

Answer: 15.4 kg/mol 

Question:  1.0 g of magnesium is burnt with 0.56 g O₂ in a closed vessel. Which reactant is left in excess and how much? (At. wt. Mg = 24; O = 16) 

• a) Mg, 0.16 g
• b) O₂, 0.16 g
• c) Mg, 0.44 g
• d) O₂, 0.28 g

Answer: Mg, 0.16 g

Question:  When 22.4 litres of H₂(g) is mixed with 11.2 litres of Cl₂ (g), each at STP, the moles of HCl(g) formed is equal to

• a) 1 mol of HCl(g)
• b) 2 mol of HCl(g)
• c) 0.5 mol of HCl(g)
• d) 1.5 mol of HCl(g)

Answer: 1 mol of HCl(g)

Question:  6.02 × 10²⁰ molecules of urea are present in 100 mL of its solution. The concentration of solution is

• a) 0.01 M
• b) 0.001 M
• c) 0.1 M
• d) 0.02 M

Answer: 0.01 M

Question:  How many grams of concentrated nitric acid solution should be used to prepare 250 mL of 2 M HNO₃ ? The concentrated acid is   HNO₃

• a) 90.0 g conc. HNO₃
• b) 70.0 g conc. HNO₃
• c) 54.0 g conc. HNO₃
• d) 45.0 g conc. HNO₃

Answer:  45.0 g conc. HNO₃

Question: Mole fraction of the solute in a 1.00 molal aqueous solution is

• a) 1.7700
• b) 0.1770
• c) 0.0177
• d) 0.0344

Answer: 0.0177

Question: Which has the maximum number of molecules among the following?

• a) 8 g H₂
• b) 64 g SO₂
• c) 44 g CO₂
• d) 48 g O₃

Answer: 8 g H₂

Question:  The number of atoms in 0.1 mol of a triatomic gas is (N_A =6.02 × 10²³ mol^–1) 

• a) 6.026 × 10²²
• b) 1.806 × 10²³
• c) 3.600 × 10²³
• d) 1.800 × 10²²

Answer:  1.806 × 10²³

Question:   25.3 g of sodium carbonate, Na₂CO₃ is dissolved in enough water to make 250 mL of solution. If sodium carbonate dissociates completely, molar concentration of sodium ion, Na⁺ and carbonate ions, 

are respectively (Molar mass of Na₂CO₃= 106 g mol^–1) 

• a) 0.955 M and 1.910 M
• b) 1.910 M and 0.955 M
• c) 1.90 M and 1.910 M
• d) 0.477 M and 0.477 M

Answer: 1.910 M and 0.955 M

Question: 10 g of hydrogen and 64 g of oxygen were filled in a steel vessel and exploded. Amount of water produced in this reaction will be

• a) 3 mol
• b) 4 mol
• c) 1 mol
• d) 2 mol

Answer: 4 mol

Question: How many moles of lead (II) chloride will be formed from a reaction between 6.5g of PbO and 3.2 g of HCl?

• a) 0.029
• b) 0.044
• c) 0.333
• d) 0.011

Answer: 0.029

Question:  Volume occupied by one molecule of water (density = 1 g cm^–3) is 

• a) 5.5 × 10^–23 cm³ 
• b) 9.0 × 10^–23 cm³ 
• c) 6.023 × 10^–23 cm³ 
• d) 3.0 × 10^–23 cm³

Answer: 3.0 × 10^–23 cm³

Question:  What volume of oxygen gas (O₂) measured at 0°C and 1 atm, is needed to burn completely 1 L of propane gas (C₃H₈₎ measured under the same conditions? 

• a) 10 L
• b) 7 L
• c) 6 L
• d) 5 L

Answer: 5 L

Question:  An element, X has the following isotopic composition ; ²⁰⁰X : 90% ; ¹⁹⁹X : 8.0% ; ²⁰²X : 2.0% The weighted average atomic mass of the naturally occurring element X is closest to :

• a) 199 amu
• b) 200 amu
• c) 201 amu
• d) 202 amu

Answer: 200 amu

Question:  Concentrated aqueous sulphuric acid is 98% H₂SO₄ by mass and has a density of 1.80 g mL^–1. Volume of acid required to make one litre of 0.1 M H₂SO₄ is 

• a) 5.55 mL
• b) 11.10 mL
• c) 16.65 mL
• d) 22.20 mL

Answer: 5.55 mL

Question: An organic compound contains carbon, hydrogen and oxygen. Its elemental analysis gave C, 38.71% and H, 9.67%. The empirical formula of the compound would be

• a) CH₄O 
• b) CH₃O
• c) CH₂O 
• d) CHO

Answer:  CH₃O

Question:  How many grams of CH₃OH should be added to water to prepare 150 ml solution of 2 M CH₃OH?

• a) 9.6 × 10³
• b) 2.4 × 10³
• c) 9.6
• d) 2.4

Answer: 9.6

Question: The number of mole of oxygen in one litre of air containing 21% oxygen by volume, under standard conditions, is

• a) 0.0093 mole
• b) 2.10 moles
• c) 0.186 mole
• d) 0.21 mole

Answer: 0.0093 mole

Question:  The total number of valence electrons in 4.2 g of N₃^– ion is (N_A is the Avogadro’s number)

• a) 2.1 N_A
• b) 4.2 N_A
• c) 1.6 N_A
• d) 3.2 N_A

Answer: 1.6 N_A