Q 1 – Who coined the term ‘Parmanu’ for the smallest indivisible particles?
(a) Leucippus
(b) L. Lavoisier
(c) Kanad
(d) None of them
(c) Kanad
Q 2 – The chemical symbol for nitrogen gas is
(a) Ni
(b) N2
(c) N+
(d) N
(b) N2
Q 3 – What is the value of Avogadro’s number?
(a) 12.044 × 1022
(b) 6.022 × 1023
(c) 3.011 × 1023
(d) 6.022 × 1022
(b) 6.022 × 1023
Q 4 – One atomic mass unit is a mass unit equal to exactly one twelfth (1/12th) the mass of one atom of ___________.
(a) Carbon-12
(b) Nitrogen -14
(c) Carbon-1
(d) Silicon-14
(a) Carbon-12
Q 5 – The chemical symbol for sodium is
(a) So
(b) Sd
(c) NA
(d) Na
Ans – (d) Na
Q 6 –Which of the following would weigh the highest?
(a) 0.2 mole of sucrose (C12 H22 O11 )
(b) 2 moles of CO2
(c) 2 moles of CaCO3
(d) 10 moles of H2O
c) 2 moles of CaCO3
Q 7 –The radius of a hydrogen atom is:
(a) 10-2
(b) 10-4
(c) 10-9
(d) 10-10
d) 10-10
Q 8 – If 12 grams of carbon has n atoms, then the number of atoms in 12 grams of magnesium will be:
(a) 2n
(b) 3n
(c) n/2
(d) n
(c) n/2
Q 9 – The most remarkable concept that Dalton’s atomic theory proposed was that of the:
(a) atomic weight
(b) atomic mass
(c) molar mass
(d) none of them
(b) atomic mass
Q 10 – Which of the following correctly represents 360 g of water?
(i) 2 moles of H2O
(ii) 20 moles of water
(iii) 6.022 × 1023 molecules of water
(iv) 1.2044 × 1025 molecules of water
(a) (i) and (iii)
(b) (i) and (iv)
(c) (ii) and (iii)
(d) (ii) and (iv)
(d) (ii) and (iv)
Q 11 – A change in the physical state can be brought about
(a) only when energy is given to the system
(b) only when energy is taken out from the system
(c) when energy is either given to or taken out from the system
(d) without any energy change
(c) when energy is either given to or taken out from the system
Q 12 – If all the reactants in a chemical reaction are completely used, which of the following statements accurately describes the relationship between the reactants and the products?
(a) The reactants must contain more complex molecules than the products do.
(b) The products must have a different physical state than the reactants.
(c) The total mass of the reactants must equal the total mass of the products.
(d) The density of the reactants must equal the density of the products.
(c) The total mass of the reactants must equal the total mass of the products
Q 13 – The relative molecular mass of Na2S2O3.5H2O is
(a) 250 amu
(b) 250 g
(c) 248 amu
(d) 248 g
(c) 248 amu
Q 14 – The percentage of calcium in calcium carbonate is
(a) 40
(b) 30
(c) 48
(d) 36
(a) 40
Q 15 – Which of the following is the correct pair of elements and its symbol?
(a) Silver – Si
(b) Sodium – So
(c) Potassium – Pt
(d) Sulphur –S
(d) Sulphur – S
Q 16 – One mole of molecules may not be equal to:
(a) 6.022 x 1023 number of molecules
(b) Given number of particles (N)
(c) Avogadro number
(d) Molecular mass in grams
(b) Given number of particles (N)
.Q 17 – What is the mass of 0.5 mole of Hydrogen atom
(a) 2.0 g
(b) 1.5 g
(c) 1 g
(d) 0.5 g
(d) 0.5 g
Q 18 – The atomic mass of carbon is:
(a) 12
(b) 14
(c) 16
(d) 23
(a) 12
Q 19 – 9 grams of water decompose to give:
(a) 4g oxygen and 16g hydrogen
(b) 2g hydrogen and 1g oxygen
(c) 8g oxygen and 1g hydrogen
(d) none
(c) 8g oxygen and 1g hydrogen
Q 20 – What mass of carbon dioxide (CO2) will contain 3.011 × 10 molecules?
(a) 11.0 g
(b) 22.0 g
(c) 4.4 g
(d) 44.0 g
(b) 22.0 g
Q 21 – A student heats 25g of reactant ‘A’ with 50g of reactant ‘B’. He obtains 50g of product ‘C’ and recovers 25 g of unreacted ‘B’.
Which of the following law is confirmed in the following reaction?
(a) Law of constant proportion
(b) Law of conservation of mass
(c) Law of conservation of mass and Law of constant proportion
(d) Law of multiple proportions
(c) Law of conservation of mass and Law of constant proportion
Q 22 – Who gave the Law of constant proportions?
(a) Cavendish
(b) Proust
(c) Dalton
(d) Lavoisier
(b) Proust
Q 23 – 9 grams of water decompose to give:
(a) 4g oxygen and 16g hydrogen
(b) 2g hydrogen and 1g oxygen
(c) 8g oxygen and 1g hydrogen
(d) none
Ans – (c) 8g oxygen and 1g hydrogen
Q 24 – Compounds composed of metals and non-metals contain:
(a) non-charged species
(b) charged species
(c) both of them
(d) none of them
(b) charged species
Q 25 – According to Law of conservation of mass, mass of reactants wil be equal to the mass of:
(a) Catalysts
(b) Products
(c) Apparatus used for reaction
(d) Gases evolved
(b) Products
Q 26 – Who gave the Law of constant proportions?
(a) Cavendish
(b) Proust
(c) Dalton
(d) Lavoisier
(b) Proust
Q 27 – How many moles are present in 40 g of He?
(a) 10 moles
(b) 11 moles
(c) 13 moles
(d) 12 moles
(a) 10 moles
Q 28 – How do atoms usually exist in nature?
(a) In the form of molecules
(b) In the form of ions
(c) In the free state
(d) In the form of molecules and Ions
(d) In the form of molecules and Ions
Q 29 – According to Law of conservation of mass, mass of reactants will be equal to the mass of:
(a) Catalysts
(b) Products
(c) Apparatus used for reaction
(d) Gases evolved
(b) Products
Q 30 –The formula of ammonium sulphate is:
(a) NHSO4
(b) NH4 SO2
(c) NHSO3
(d) (NH4 )2 SO4
Ans – (d) (NH4 )2 SO4
Q 31 – Identify the symbol used to represent Avogadro’s number.
(a) MA
(b) AO
(c) AN
(d) NA
(d) NA
Q 32 – How many times an atom of sulphur is heavier than an atom of carbon?
(a) 32 times
(b) 12 times
(c) 8/3 times
(d) 12/32 times
(c) 8/3 times
Q 33 –The word “mole” was introduced around 1896 by:
(a) Wilhelm Ostwald
(b) John Dalton
(c) Avogadro
(d) Vergilious
(a) Wilhelm Ostwald
Q 34 – How do atoms usually exist in nature?
(a) In the form of molecules
(b) In the form of ions
(c) In the free state
(d) In the form of molecules and Ions
(d) In the form of molecules and Ions
Q 35 –The number of oxygen atoms in 4.4 g of CO2 is approx.
(a) 6 × 1022
(b) 6 × 1024
c) 12 × 1023
(d) 1.2 × 1023
(d) 1.2 × 1023
(c) Atom can neither be created nor destroyed.
Q 37 –What is the mass of 0.5 mole of Hydrogen atom
(a) 2.0 g
(b) 1.5 g
(c) 1 g
(d) 0.5 g
(d) 0.5 g
Q 38 – Which of the following represents 12 u?
(a) Mass of 1 hydrogen atom
(b) Mass of C-12 atom
(c) Mass of 0-16 atom
(d) 1/12th of mass of C-12 atom
(b) Mass of C-12 atom
Q 39 – The chemical symbol for sodium is:
(a) So
(b) Sd
(c) NA
(d) Na
(d) Na
Q 40 – The number of atoms present in one molecule of an element is called as:
(a) Empirical formula
(b) Molecule
(c) Atomicity
(d) Compound
(c) Atomicity
Q 41 – Valency of hydrogen is 1 and that of sulphur is 2. What should be the formula of hydrogen sulphide?
(a) HS
(b) H2S2
(c) HS2
(d) H2S
(d) H2S
Q 42 – Calculate the formula unit mass of ZnCl2?
(a) 137 u
(b) 124 u
(c) 123 u
(d) 111 u
(a) 137 u
Q 43 – The molecule having atomicity of 4 is:
(a) Sulphate molecule
(b) Ozone molecule
(c) Phosphorus molecule
(d) Methane molecule
(c) Phosphorus molecule
Q 44 –Which of the following has a maximum number of atoms?
(a) 18 g of H2 O
(b) 18 g of O2
(c) 18 g of CO2
(d) 18 g of CH4
(d) 18 g of CH4
Q 45 – Which of the following pair of elements represents a mole ratio of 1:1?
(a) 20 g of sodium and 20 g of calcium
(b) 7 g of nitrogen and 12 gm of sodium
(c) 10 g of calcium and 6 g of carbon
(d) 14 of nitrogen and 24 g of magnesium
(d) 14 g of nitrogen and 24 g of magnesium
Q 46 – Calculate the number of Mg atoms in 0.024 g of Mg
(a) 6.022 × 1021 Mg atoms
(b) 6.22 × 1023 Mg atoms
(c) 6.022 × 1020 Mg atoms
(d) 6.022 × 1025 Mg atoms
(c) 6.022 × 1020 Mg atoms
Q 47 – Which of the following is the correct IUPAC symbol for the element Cobalt?
(a) Co
(b) Cb
(c) C
(d) none of these
(a) Co
Q 48 – Which of the following contains a maximum number of molecules?
(a) 1g CO2
(b) 1g N2
(c) 1g H2
(d) 1g CH4
(c) 1g H2
Q 49 – Which of the following is the major drawback of Dalton’s atomic theory?
(a) Atoms of an element have exactly the same mass.
(b) Atoms are indivisible.
(c) Atoms of different elements have different masses.
(d) All of the above
(b) Atoms are indivisible
Q 50 – Fill in the blank:
In a compound such as water, the ratio of the mass of hydrogen to the mass of oxygen is always 1:8
- Atomic radius is measured in Nanometres
- The symbol of iron is Fe from its Latin name Ferrum
- One atomic mass unit is a mass unit equal to exactly 1/12th the mass of one atom of carbon-12.
- The formula unit mass of a substance is a sum of the atomic masses of all its constituent atoms.
- Avogadro number is represented by No
- The relative mass of atoms of all elements is obtained by comparing them with the mass of a carbon-12 atom.
- The Avogadro constant 6.022 × 1023 is defined as the number of atoms in exactly 12g of carbon-12.
Q 51 – True and False
- An atom is the smallest particle of the element that cannot usually exist independently and retains all its chemical properties [True]
- The Law of conservation of mass states that mass can neither be created nor destroyed in a chemical reaction.[True]
- The mass of 1 mole of a substance is equal to its relative atomic or molecular mass in grams [True]
- 16u oxygen has 16 atoms of oxygen [False]
- The atomic mass of calcium is 40. [True]
- Aluminum is diatomic [False]
Q 52 –Match the column
| A 1. 1 mole of carbon atoms 2. 1 mole of molecules 3. 1 mole of hydrogen atoms 4. 1 mole of any particle (atoms, molecules, ions) |
B (i) 1 g of H atoms (ii) Molecular mass in gram (iii) Relative mass of those particles in gram (iv) 12-gram carbon atoms |
| A 1. 1 mole of carbon atoms 2. 1 mole of molecules 3. 1 mole of hydrogen atoms 4. 1 mole of any particle (atoms, molecules, ions) |
B |
Q 53 – Which of the following can be used to see atoms?
(a) Scanning tunneling microscope
(b) Microscope
(c) Most powerful microscope
(d) Optical microscope
(a) Scanning tunneling microscope
Q 54 – Which one of the following is the modern symbol of Gold?
(a) Gl
(b) Go
(c) Si
(d) Au.
(d) Au
Q 55 – NaCl molecule is made of which of the following ions?
(a) Na cation and Cl anion
(b) Cl cation and Na anion
(c) Both Na and Cl cation
(d) Both Na and Cl anion
(a) Na cation and Cl anion
Q 56 – An atom has a mass number of 23 and atomic number 11. The number of protons are ________.
(a) 11
(b) 12
(c) 23
(d) 44
(a) 11
Q 57 – The balancing of chemical equation is based upon:
(a) Law of conservation of mass
(b) Law of multiple proportions
(c) Law of definite proportion
(d) Law of combining volumes
(a) Law of conservation of mass
Q 58 – The number of moles of oxygen atoms in two moles of nitric acid is:
(a) 2
(b) 4
(c) 8
(d) 6
(d) 6
Q 59 – During a chemical reaction, the sum of the masses of the reactants and products remains unchanged. This is known as
(a) Law of conservation of mass
(b) Law of multiple proportions
(c) Law of constant proportion
(d) None of these
(a) Law of conservation of mass
Q 60 – Who was the first to use the symbols for elements?
(a) Joseph L Proust
(b) Berzillius
(c) Antoine L Lavoisier
(d) Dalton
(d) Dalton
Q 61 – Valency of Calcium element is:
(a) 4
(b) 5
(c) 2
(d) 3
(c) 2
Q 62 – The mass of 0.5 moles of Water molecules is:(Atomic mass, H =1; O = 16)
(a) 27 g
(b) 0.5 g
(c) 9 g
(d) 18 g
(c) 9 g
Q 63 – Who stated the Law of conservation of mass?’
(a) Thomson
(b) Lavoisier
(c) Dalton
(d) Cavendish
(b) Lavoisier
Q 64 – Which constituent of air is monoatomic?
(a) Argon
(b) Water vapour
(c) Oxygen
(d) Nitrogen
(a) Argon
Q 65 – Fill in the blanks
- In a chemical reaction, the sum of the masses of the reactants and products remain unchanged. This is called Law of Conservation of Mass
- A group of atoms carrying a fixed charge on them is called Polyatomic ion
- The formula unit mass of Ca3 (PO4 )2 is (3 × atomic mass of calcium) + (2 × atomic mass of phosphorus) + (8 × atomic mass of oxygen) = 310
- Formula of sodium carbonate is Na2CO3 and that of ammonium sulphate is (NH4)2 SO4
- Elements are represented by symbols and molecules by Chemical formula
- The combining power of an element is known as its Valency
- An atom or a group of atoms which carries positive or negative charge is called an ion
- The volume occupied by one mole of a gas under standard conditions of temperature and pressure is called molar volume
- The number of atoms present in one molecule of the substance is called its atomicity
- Atomicity of H2 SO4 is 7
Q 66 – Match the following columns
| Column I | Column II |
| (a) 28 g of He | (i) 58.54 |
| (b) 0.5 mole of O | (ii) 7 mol |
| (c) Molecular mass of common salt | (iii) 60 g |
| (d) 1.5 mole of Ca | (iv) 16 g |
Ans –
| Column I | Column II |
| (a) 28 g of He | (ii) 7 mol |
| (b) 0.5 mole of O | (iv) 16 g |
| (c) Molecular mass of common salt | (i) 58.54 |
| (d) 1.5 mole of Ca | (iii) 60 g |