NEET Chemistry Some Basic Concepts Of Chemistry MCQs Set B

Question:  The amount of zinc required to produce 224 ml of H₂ at STP on treatment with dilute H₂SO₄ will be (Zn = 65)

• a) 65 g
• b) 0.065 g
• c) 0.65 g
• d) 6.5 g

Answer: 0.65 g

Question: Given the numbers : 161 cm, 0.161 cm, 0.0161 cm. The number of significant figures for the three numbers is

• a) 3, 3 and 4 respectively
• b) 3, 4 and 4 respectively
• c) 3, 4 and 5 respectively
• d) 3, 3 and 3 respectively

Answer: 3, 3 and 3 respectively

Question:  Change in volume when 100 mL PH₃ decomposed to solid phosphorus and H₂ gas.

• a) Increase in 50 mL
• b) Decrease in 50 mL
• c) Increase in 150 mL
• d) Decrease in 200 mL

Answer: Increase in 50 mL

Question:  In the reaction, 

When 1 mole of ammonia and 1 mole of O₂ are made to react to completion

• a) All the oxygen will be consumed
• b) 1.0 mole of NO will be produced
• c) 1.0 mole of H₂O is produced 
• d) All the ammonia will be consumed

Answer: All the oxygen will be consumed

Question: An organic compound containing C, H and N gave the following analysis C = 40%, H = 13.33%, N = 46.67%. Its empirical formula would be

• a) CH₄N 
• b) CH₅N
• c) C₂H₇N₂ 
• d) C₂H₇

Answer:  CH₄N 

Question: How many g of dibasic acid (mol. weight 200) should be present in 100 ml. of the aqueous solution to give strength of 0.1 N?

• a) 10 g
• b) 2 g
• c) 1 g
• d) 20 g

Answer: 1 g

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

• a) 4 × 10²³
• b) 2 × 20²³ 
• c) 1 × 10²³
• d) 6 × 10²³

Answer:  6 × 10²³

Question:  Volume of CO₂ obtained at STP by the complete decomposition of 9.85 gm BaCO₃ is (Mol. wt. of BaCO₃=197)

• a) 2.24 litre
• b) 1.12 litre
• c) 0.85 litre
• d) 0.56 litre

Answer: 0.85 litre

Question: Percentage of Se in peroxidase anhydrous enzyme is 0.5% by weight (at. wt. = 78.4) then minimum molecular weight of peroxidase anhydrous enzyme is

• a) 1.568 × 10⁴
• b) 1.568 × 10³
• c) 15.68
• d) 2.136 × 10⁴

Answer:  1.568 × 10⁴

Question: 2.5 litre of 1 M NaOH solution mixed with another 3 litre of 0.5 M NaOH solution. Then find out molarity of resultant solution.

• a) 0.80 M
• b) 1.0 M
• c) 0.73 M
• d) 0.50 M

Answer: 0.73 M

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

Question: Which has maximum molecules?

• a) 7 gm N₂ 
• b) 2 gm H₂
• c) 16 gm NO₂  
• d) 16 gm O₂

Answer:  2 gm H₂

Question: In Haber process 30 litres of dihydrogen and 30 litres of dinitrogen were taken for reaction which yielded only 50% of the expected product. What will be the composition of gaseous mixture under the aforesaid condition in the end?

• a) 20 litres ammonia, 20 litres nitrogen, 20 litres hydrogen
• b) 10 litres ammonia, 25 litres nitrogen, 15 litres hydrogen
• c) 20 litres ammonia, 10 litres nitrogen, 30 litres hydrogen
• d) 20 litres ammonia, 25 litres nitrogen, 15 litres hydrogen

Answer: 10 litres ammonia, 25 litres nitrogen, 15 litres hydrogen

Question: The maximum number of molecules is present in

• a) 15 L of water at STP
• b) 15 L of H₂O gas at STP
• c) 15 g of ice
• d) Same in all

Answer: 15 L of water at STP

Question:  Concentrated aqueous sulphuric acid is 98% H₂SO₄ (w/v) and has a density of 1.80 gmL^–1. Molarity of solution

• a) 1 M
• b) 1.8 M
• c) 10 M
• d) 1.5 M

Answer: 10 M

Question:   An element, X has the following isotopic composition ⁵⁶X : 90% ⁵⁷X : 8% ⁵⁹X : 2.0%. The weighted average atomic mass of the naturallyoccurring element X is closest to

• a) 56.14 amu
• b) 56.8 amu
• c) 60 amu
• d) 55 amu

Answer: 56.14 amu

Question: 10 g of hydrogen and 64 g of oxygen were filled in a steel vessel and exploded. Volume of gaseous product after reaction

• a) 1 × 22.4 L
• b) 2 × 22.4 L
• c) 3 × 22.4 L
• d) 4 × 22.4 L

Answer: 1 × 22.4 L

Question:  What is the [OH^–] in the final solution prepared by mixing 20.0 mL of 0.050 M HCl with 30.0 mL of 0.10 M Ba(OH)₂ ?

• a) 0.12 M
• b) 0.10 M
• c) 0.40 M
• d) 0.0050 M

Answer: 0.10 M

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

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

Answer:  1.806 × 10²³ 

Question:  The total number of electrons in 2.0 g of D₂O to that in 1.8 g of H₂O

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

Answer: Same

Question:  From 200 mg of CO₂ when x molecules are removed, 2.89 × 10^–3 moles of CO₂ are left. x will be

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

Answer:  10²¹ molecules

Question: If the weight of metal oxide is x g containing y g of oxygen, the equivalent weight of metal will be

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:  The number of significant figures in 2.653 × 10⁴ is

• a) 8
• b) 4
• c) 7
• d) 1

Answer: 4

Question: Mole fraction of solute in aqueous solution of 30% NaOH.

• a) 0.16
• b) 0.05
• c) 0.25
• d) 0.95

Answer: 0.16

Question:  Change in volume when 100 mL PH₃ decomposed to solid phosphorus and H₂ gas.

• a) Increase in 50 mL
• b) Decrease in 50 mL
• c) Increase in 150 mL
• d) Decrease in 200 mL

Answer: Increase in 50 mL

Question: Given the numbers : 161 cm, 0.161 cm, 0.0161 cm. The number of significant figures for the three numbers is

• a) 3, 3 and 4 respectively
• b) 3, 4 and 4 respectively
• c) 3, 4 and 5 respectively
• d) 3, 3 and 3 respectively

Answer: 3, 3 and 3 respectively

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: 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: 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: 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: 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