# MCQ Questions for Class 11 Chemistry Chapter 1 Some Basic Concepts of Chemistry with Answers

We have compiled the NCERT MCQ Questions for Class 11 Chemistry Chapter 1 Some Basic Concepts of Chemistry with Answers Pdf free download covering the entire syllabus. Practice MCQ Questions for Class 11 Chemistry with Answers on a daily basis and score well in exams. Refer to the Some Basic Concepts of Chemistry Class 11 MCQs Questions with Answers here along with a detailed explanation.

## Some Basic Concepts of Chemistry Class 11 MCQs Questions with Answers

Multiple Choice Type Questions

Question 1.
What will be the volume of mixture after the reaction

(a) 1.5 L
(b) 0.5 L
(c) 1 L
(d) 0.0 L

Question 2.
A compound has haemoglobin like structure, it has only one Fe. It contains 4.6% of Fe. The approximate molecular mass is
(a) 100 g mol-1
(b) 1200 g mol-1
(c) 1400 g mol-1
(d) 1600 g mol-1

Question 3.
How much of NaOH is required to neutralise 1500 cm³ of 0.1 NHCl?
(a) 40 g
(b) 4 g
(c) 6 g
(d) 60 g

Question 4.
10 dm³ of N2 gas and 10 dm³ of gas X at the same temperature contains the same number of molecules. The gas X is
(a) CO
(b) CO2
(c) H2
(d) NO

Question 5.
The percentage of nitrogen in urea is about
(a) 46
(b) 85
(c) 18
(d) 28

Question 6.
The modem atomic weight scale is based upon
(a) 12C
(b) 12O8
(c) 1H
(d) 13C

Question 7.
The prefix 1018 is
(a) giga
(b) exa
(c) kilo
(d) nano
(e) mega

Question 8.
Number of atoms in 558.6 g Fe (Molar mass Fe = 55.86 g mol-1) is
(a) twice that in 60 g carbon
(b) 6.023 × 1022
(c) half that of 8g He
(d) 558.6 × 6.023 × 1023

Answer: (a) twice that in 60 g carbon

Question 9.
Number of grams of oxj^gen in 32.2 g Na2SO4.10 H2O is
(a) 20.8
(b) 22.4
(c) 2.24
(d) 2.08

Question 10.
250 ml of a sodium carbonate solution contains 2.65 grams of Na2CO3. If 10 ml of this solution is diluted to one litre, what is the concentration of the resultait| solution (mol. wt. of Na2CO3 = 106)
(a) 0.1 M
(b) 0.001 M
(c) 0.01 M
(d) 10-4 M

Question 11.
An aqueous solution of 6.3 g of oxalic acid dihydrate is made upto 250 ml. The volume of 0.1 N NaOH required to completely neutralise 10 ml of this solution is
(a) 40 ml
(b) 20 ml
(c) 10 m
(d) 4 ml

Question 12.
How many moles of electrons weight one kilogram?
(a) 6.023 × 1023
(b) $$\frac {1}{9.108}$$ × 1031
(c) $$\frac {6023×10^{54}}{9.108}$$
(d) 9.108 × 108

Question 13.
One mole of calcium phosphide on reaction with excess of water gives
(a) One mole of phosphine
(b) Two moles of phosphoric acid
(c) Two moles of phosphine
(d) One mole of phosphorous pentoxide

Answer: (c) Two moles of phosphine

Question 14.
Which has maximum number of atoms?
(a) 24 g of C (12)
(b) 56 g of Fe (56)
(c) 27 g of Al (27)
(d) 108 g of Ag (108)

Answer: (a) 24 g of C (12)

Question 15.
Mixture X = 0.02 mol of [CO(NH3)5 SO4] Br and 0.02 mol of [CO(NH3)5 Br] SO4 was prepared in 2 litres of a solution.
1 litre of mixture X + excess of AgNO3 → Y
1 litre of mixture X + excess of BaCl2 → Z
Number of moles of Y and Z are
(a) 0.01, 0.01
(b) 0.02, 0.01
(c) 0.01, 0.02
(d) 0.02, 0.02

Question 16.
7.5 grams of a gas occupy 5.6 litres of volume at STP. The gas is
(a) NO
(b) N2O
(c) CO
(d) CO2

Question 17.
The percentage of Se in peroxidase anhydrous enzyme is 0.5% by weight [Atomic mass = 78.4]. Then minimum molecular weight of peroxidase anhydrous enzyme is
(a) 1568 × 104
(b) 1.568 × 103
(c) 15.68
(d) 3.136 × 104

Question 18.
Assuming fully decomposed, the volume of CO2 released at STP in heating 9.85 g BaCO3 [Atomic mass of Ba = 137] will be
(a) 0.84 I.
(b) 2.24 L
(c) 4.06 L
(d) 11.12 L

Question 19.
Number of water molecules present in a drop of water (volume 0.0018 ml) at room temperature is
(a) 6.023 × 1019
(b) 1.084 × 1018
(c) 4.84 × 1017
(d) 6.023 × 1023

Question 20.
The weight of a molecule of the compound C60H22 is
(a) 1.4 × 10-21 g
(b) 1.09 × 10-21 g
(c) 5.025 × 1023 g
(d) 16.023 × 1023 g

Answer: (a) 1.4 × 10-21 g

Fill in the Blanks

Question 1.
The S.I. unit of pressure is ………………

Answer: Nm-2 or kg m-1 s-1

Question 2.
The symbol ‘u’ used for expressing atomic mass and molecular mass represents ……………… scale based on ……………… isotope.

Question 3.
The reactant which reacts completely and decides the amount of the product is called ………………

Question 4.
A pure substance that contains only one kind of atoms is called ………………

Question 5.
The law which states that a chemical compound always contains the same elements combined in a fixed ratio by mass is called ………………

True/False Statements

Question 1.
22.4 L of all gases at STP contains 6.023 × 1023 molecules/atoms.

Question 2.
The zeros on the right of a decimal point are not significant.

Question 3.
Petrol is homogeneous mixture of a number of hydrocarbons.

Question 4.
Mass of the reactants is always equal to the mass of the products.

Question 5.
The volumes of oxygen which combine with a fixed volume of nitrogen in N2O, NO and NO2 bear a simple ratio to one another.

Question 6.
Equal volumes of different gases under similar conditions of temperature and pressure contain equal number of atoms.

Question 7.
Atom is not indestructible.

Question 8.
Empirical formula represents the actual number of atoms present in a molecule of the substance.

Question 9.
A balanced equation contains equal number of atoms of each elements on both sides of the equation.

Question 10.
Equal moles of two or more gases occupy equal volumes under similar conditions of temperature and pressure.

Matching Type Questions

 Column I Column II 1. Petrol 1. Compound 2. Brass 2. Element 3. Sugar 3. 6.02 × 1023 4. Gold 4. Mixture 5. Avogadro’s Number 5. Mixture