CBSE Class 11 Stoichiometry and Stoichiometric Calculations Worksheet A

Question. What is the concentration of nitrate ions if equal volumes of 0.1 M AgNO₃ and 0.1 M NaCl are mixed together?
a. 0.1 M
b. 0.2 M
c. 0.05 M
d. 0.25 M
Answer : C

Question. 74.5 g of a metallic chloride contain 35.5 g of chlorine.
The equivalent weight of the metal is:
a. 19.5
b. 35.5
c. 39.0
d. 78.0
Answer : C

Question. The atomic weights of two elements A and B are 40 and 80 respectively. If x g of A contains y atoms, how many atoms are present in 2x g of B?
a. y/2
b. y/4
c. y
d. 2y
Answer : C

Question. Which of the following is the best example of law of conservation of mass?
a. 12 g of carbon combines with 32 g of oxygen to form 44 g of CO₂
b. When 12 g of carbon is heated in a vacuum there is no change in mass
c. A sample of air increases in volume when heated at constant pressure but its mass remains unaltered
d. The weight of a piece of platinum is the same before and after heating in air
Answer : A

Question. n g of substance X reacts with m g of substance Y to form p g of substance R and q g of substance S. This reaction can be represented as, X + Y = R + S.The relation which can be established in the amounts of the reactants and the products will be
a. n  –m = p –q
b. n + m = p + q
c. n = m
d. p = q
Answer : B

Question. Sulphur forms the chlorides S₂Cl₂ and SCl₂ .The equivalent mass of sulphur in SCl₂ is:
a. 8 g/mole
b. 16 g/mole
c. 64.8 g/mole
d. 32 g/mole
Answer : B

Question. 1.520 g of the hydroxide of a metal on ignition gave 0.995 gm of oxide. The equivalent weight of metal is:
a. 1.520
b. 0.995
c. 19.00
d. 9.00
Answer : D

Question. Caffeine has a molecular weight of 194. If it contains 28.9% by mass of nitrogen, number of atoms of nitrogen in one molecule of caffeine is:
a. 4
b. 6
c. 2
d. 3
Answer : A

Question. One litre of a gas at STP weight 1.16 g it can possible be:
a. C₂H₂
b. CO
c. O₂
d. CH₄
Answer : A

Question. 1.25 g of a solid dibasic acid is completely neutralised by 25 ml of 0.25 molar Ba(OH)₂ solutions. Molecular mass of the acid is:
a. 100
b. 150
c. 120
d. 200
Answer : D

Question. A gaseous mixture contains CH₄ and C₂H₆ in equimolecular proportion. The weight of 2.24 litres of this mixture at NTP is:
a. 4.6 g
b. 1.6 g
c. 2.3 g
d. 23 g
Answer : C

Question. The equivalent weight of a metal is 9 and vapour density of its chloride is 59.25. The atomic weight of metal is:
a. 23.9
b. 27.3
c. 36.3
d. 48.3
Answer : A

Question. What should be the equivalent weight of phosphorous acid, if P = 31; O = 16; H = 1?
a. 82
b. 41
c. 20.5
d. None of these
Answer : B

Question. The weight of a molecule of the compound C₆₀H₁₂₂ is:
a. 1.4x10^–21 g
b. 1.09x10^–21 g
c. 5.025x10²³ g
d. 16.023x10²³ g
Answer : A

Question. Equivalent weight of a bivalent metal is 37.2. The molecular weight of its chloride is:
a. 412.2
b. 216
c. 145.4
d. 108.2
Answer : C

Question. 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 resultant solution (mol. wt. of Na₂CO₃ = 106) ?
a. 0.1 M
b. 0.001 M
c. 0.01 M
d. 10–4M
Answer : B

Question. The prefix zepto stands for:
a. 10⁹
b. 10^–12
c. 10^–15
d. 10^–21
Answer : D

Question. The number of significant figures in 60.0001 is:
a. 5
b. 6
c. 3
d. 2
Answer : B

Question. Volume of a gas at STP is 1.12x10^–7 cc. Calculate the number of molecules in it:
a. 3.01x10²⁰
b. 3.01x10¹²
c. 3.01x10²³
d. 3.01x10²⁴
Answer : B

Question. The number of molecules in 4.25 g of ammonia are:
a. 0.5x10²³
b. 1.5x10²³
c. 3.5x10²³
d. 1.8x10³²
Answer : B

Question. Which one of the following pairs of gases contains the same number of molecules?
a. 16 g of O₂ and 14 g of N₂
b. 8 g of O₂ and 22 g of CO₂
c. 28 g of N₂ and 22 g of CO₂
d. 32 g of O₂ and 32 g of N₂
Answer : A

Question. Molarity of liquid HCl with density equal to 1.17g/cc is:
a. 36.5
b. 18.25
c. 32.05
d. 4.65
Answer : C

Question. A sample of phosphorus trichloride (PCl₃) contains 1.4 moles of the substance. How many atoms are there in the sample?
a. 4
b. 5.6
c. 8.431x10²³
d. 3.372x10²⁴
Answer : C

Question. The percentage of oxygen in NaOH is:
a. 40
b. 60
c. 8
d. 10
Answer : A

Question. The number of water molecules in 1 litre of water is:
a. 18
b. 18x1000
c. N_A
d. 55.55N_A
Answer : D

Question. b. Which of the following is Loschmidt number?
a. 6 x 10²³
b. 2.69 x 10¹⁹
c. 3 x 10²³
d. None of these
Answer : B

Question. The total number of gm-molecules of SO₂Cl₂ in 13.5g of sulphuryl chloride is:
a. 0.1
b. 0.2
c. 0.3
d. 0.4
Answer : A

Question. The number of moles of oxygen in 1 L of air containing 21% oxygen by volume, in standard conditions, is:
a. 0.186 mol
b. 0.21 mol
c. 2.10 mol
d. 0.0093 mol
Answer : D

Question. The number of oxygen atoms in 4.4 g of CO₂ is approx:
a. 1.2x10²³
b. 6x10²²
c. 6x10²³
d. 12x10²³
Answer : A

Question. 19.7 kg of gold was recovered from a smuggler. How many atoms of gold were recovered? (Au =197)
a. 100
b. 6.02x10²³
c. 6.02x10²⁴
d. 6.02x10²⁵
Answer : D

Question. In which of the following pairs of compounds the ratio of C, H and O is same?
a. Acetic acid and methyl alcohol
b. Glucose and acetic acid
c. Fructose and sucrose
d. All of these
Answer : B

Question. How much of NaOH is required to neutralise 1500 cm³ of 0.1 NHCl (Na = 23)?
a. 40 g
b. 4 g
c. 6 g
d. 60 g
Answer : C

Question. The percentage of Se in peroxidase anhydrous enzyme is 0.5% by weight (atomic weight=78.4). Then minimum molecular weight of peroxidase anhydrous enzyme is:
a. 1.568x10⁴
b. 1.568x10³
c. 15.68
d. 3.136x10⁴
Answer : A

Question. What is the % of H₂ Oin Fe(CNS)₃. 3H₃O ?
a. 45
b. 30
c. 19
d. 25
Answer : C

Question. In order to prepare one litre normal solution of KMnO₄, how many grams of KMnO₄ are required if the solution is used in acidic medium for oxidation?
a. 158 g
b. 31.6 g
c. 790 g
d. 62 g
Answer : B

Question. 2.76 g of silver carbonate on being strongly heated yield a residue weighing:
a. 2.16 g
b. 2.48 g
c. 2.64 g
d. 2.32 g
Answer : A

Question. Haemoglobin contains 0.33% of iron by weight. The molecular weight of haemoglobin is approximately 67200. The number of iron atoms (At. wt. of Fe = 56) present in one molecule of haemoglobin is:
a. 6
b. 1
c. 4
d. 2
Answer : C

Question. The percentage of P₂O₅ in diammonium hydrogen phosphate (NH₄)₂HPO₄ is:
a. 23.48
b. 46.96
c. 53.78
d. 71.00
Answer : C

Question. The percentage of nitrogen in urea is about:
a. 46
b. 85
c. 18
d. 28
Answer : A

Question. The empirical formula of a compound is H₂O. 0.0835 moles of the compound contains 1.0 g of hydrogen.
Molecular formula of the compound is:
a. C₂H₁₂O₆
b. C₃H₁₀O₅
c. C₄H₈O₈
d. C₃H₆O₃
Answer : A

Question. In the preceeding question, the amount of Na₂CO₃ present in the solution is:
a. 2.650 g
b. 1.060 g
c. 0.530 g
d. 0.265 g
Answer : C

Question. How many g of a dibasic acid (Mol. wt. = 200) should be present in 100 ml of its aqueous solution to give decinormal strength?
a. 1 g
b. 2 g
c. 10 g
d. 20 g
Answer : A

Question. The vapour density of a mixture containing NO₂ and N₂O₄ is 38.3 at 27^oC. Which of the following is correct for 100 moles of mixture?
a. Moles of NO₂ in mixture are 33.48
b. Moles of N₂O₄ in mixture are 66.52
c. Weight of NO₂ in mixture is 1540 g
d. Weight of N₂O₄ in mixture is 1540 g
Answer : B,D

Question. 100 g CaCO₃ reacts with 1litre 1 N HCl. On completion of reaction how much weight of CO₂ will be obtain?
a. 5.5 g
b. 11 g
c. 22 g
d. 33 g
Answer : C

Question. 0.16 g of dibasic acid required 25 ml of decinormal NaOH solution for complete neutralisation. The molecular weight of the acid will be:
a. 32
b. 64
c. 128
d. 256
Answer : C

Question. A mixture of sand and iodine can be separated by:
a. Crystallisation
b. Sublimation
c. Distillation
d. Fractional distillation
Answer : B

Question. In which of the following number, all zeroes are significant?
a. 4,00004
b. 0.0060
c. 20.000
d. 0.800
Answer : A, B, C

Question. The mass of BaCO₃ produced when excess CO₂ is bubbled through a solution of 0.205 mol Ba(OH)₂ is?
a. 81 g
b. 40.5 g
c. 20.25 g
d.162 g
Answer : B

Question. What is the normality of a 1 M solution of H₃PO₄ ?
a. 0.5 N
b. 1.0 N
c. 2.0 N
d. 3.0 N
Answer : D

Question. Select the correct statements:
a. At STP, volume occupied by one mole liquid water is 22.4 litre
b. Volume occupied by 1g H₂ gas at STP is equal to volume occupied by 2 g He at STP
c. 1 g of CH₄ real gas occupies 1.4 litre volume at STP
d. SO₂Cl₂ reacts with H₂O to give mixture of H₂SO₄ , HCl. Aqueous solution of 1 mole SO₂Cl₂ will be neutralized by 2 mole of Ca(OH)₂
Answer : A, B, D

Question. How many grams of caustic potash required to completely neutralise 12.6 gm HNO₃ ?
a. 22.4 KOH
b. 1.01 KOH
c. 6.02 KOH
d. 11.2 KOH
Answer : D

Question. The maximum amount of BaSO₄ precipitated on mixing equal volumes of BaCl₂ (0.5 M) with H₂SO₄ (1M) will correspond to:
a. 0.5 M
b. 1.0 M
c. 1.5 M
d. 2.0 M
Answer : A

Question. M is the molecular weight of KMnO₄ . The equivalent weight of KMnO₄ when it is converted into K₂MnO₄ is?
a. M
b. M/3
c. M/5
d. M/7
Answer : A

Question. The equivalent weight of phosphoric acid (H₃PO₄) in the reaction NaOH+H₃PO₄ → NaH₂PO₄ +H₂ O is:
a. 25
b. 49
c. 59
d. 98
Answer : D

Question. Volume of 0.6 M NaOH required to neutraliz 30 cm³ of 0.4 M HCl is:
a. 30 cm³
b. 20 cm³
c. 50 cm³
d. 45 cm³
Answer : B

Question. Which of the statements are true? Where Mw is the molecular weight of the respective compounds:
a. The equivalent weight of Ca₃ (PO₄)₂ is Mw/6.
b. The equivalent weight of Na₃ PO₄ - 12H₂O is Mw/3
c. The equivalent weight of K₂SO₄ is Mw/2
d. The equivalent weight of potash alum K₂SO₄Al₂(SO₄)₃ - 24H₂O is Mw/8
Answer : ALL

Question. On electrical decomposition of 150 ml dry and pure O₂ ,10% of O₂ gets changed to O, then the volume of gaseous mixture after reaction and volume of remaining gas left after passing in turpentine oil will be:
a. 145 ml
b. 149 ml
c. 128 ml
d. 125 ml
Answer : A

Question. A solution of M ml M/10 FeSO₄ was titrated with KMnO₄ solution in acidic medium. The amount of KMnO₄ used will be:
a. 5 ml of 0.1 M
b. 10 ml of 1.1 M
c. 10 ml of 0.5 M
d. 10 ml of 0.02 M
Answer : D

Question. Which of the following statements are true?
a. One gram atom of carbon contains Avogadro’s number of atoms
b. One mole oxygen gas contains Avogardro’s number of molecules
c. One mole of the hydrogen molecules contains Avogardro’s number of atoms
d. One mole of electrons stands for 6.023×10²³ electrons
Answer : A, C

Question. Two bulbs A and B contain 16g O₂ and 16g O₃, respectively.
Which of the statements are true?
a. Both bulbs contain same number of atoms
b. Both bulbs contain different number of atoms
c. Both bulbs contain same number of molecules
d. Bulb A contains NA/2 molecules while bulb B contains
NA/3 molecules. (NA = Avogadro’s number).
Answer : A, D

Question. 2 moles of CaCO₃ present in 1 litre aqueous solution has a density equal to 1.2 g/cc equal to:
a. 2 M solution of CaCO₃
b. 4 N solution of CaCO₃
c. Solution with mole fraction of CaCO₃ is 0.0347
d. Solution which contains 55.5 moles of water
Answer : ALL

Question. A bulb contains 1.6 g of O₂. It contains.
a. 0.05 mol of O₂
b. 3.011×10²² molecules of O₂
c. 1.12 L of O₂ at STP
d. 1.22 L of O₂ at SATP
Answer : ALL

Assertion and Reason

Note: Read the Assertion (A) and Reason (R) carefully to mark the correct option out of the options given below:
a. If both assertion and reason are true and the reason is the correct explanation of the assertion.
b. If both assertion and reason are true but reason is not the correct explanation of the assertion.
c. If assertion is true but reason is false.
d. If the assertion and reason both are false.
e. If assertion is false but reason is true.

Question. Assertion: One mole of SO₂ contains double the number of molecules present in one mole of O₂.
Reason: Molecular weight of SO₂ is double to that of O₂.
Answer : E

Question. Assertion: Atoms can neither be created nor destroyed.
Reason: Under similar condition of temperature and pressure, equal volume of gases does not contain equal number of atoms.
Answer : 

Question. Assertion: Molecular weight of oxygen is 16.
Reason: Atomic weight of oxygen is 16.
Answer : E

Question. Assertion: As mole is the basic chemical unit, the concentration of the dissolved solute is usually specified in terms of number of moles of solute.
Reason: The total number of molecules of reactants involved in a balanced chemical equation is known as molecularity of the reaction.
Answer : B

Question. Assertion: 22.4 L of N₂ at NTP and 5.6 L O₂ at NTP contain equal number of molecules.
Reason: Under similar conditions of temperature and pressure all gases contain equal number of molecules.
Answer : D

Question. Assertion: One atomic mass unit (amu) is mass of an atom equal to exactly one-twelfth the mass of a carbon-12 atom.
Reason: Carbon-12 isotope was selected as standard.
Answer : A

Question. Assertion: Volume of a gas is inversely proportional to the number of moles of a gas.
Reason: The ratio by volume of gaseous reactants and products is in agreement with their mole ratio.
Answer : E

Question. Assertion: Equivalent weight of Cu in CuO is 63.6 and in Cu₂O31.8.
Reason: Equivalent weight of an element
= Atomic weight of the element / Valency of the element
Answer : E

Question. Assertion: 1 amu equals to 1.66x10^–24 g.
Reason: 1.66×10^–24g equals to (1/12)^th of mass of C¹² atom.
Answer : A

Question. Assertion: Atomicity of oxygen is 2.
Reason: 1 mole of an element contains 6.023×10²³ atoms.
Answer : B

Comprehension Based

Paragraph –I

An aqueous solution of NaOH having density 1.1 kg / dm³ contains 0.02 mole fraction of NaOH.

Question. The molality and molarity of NaOH solution respectively are:
a. 0.986, 1.134
b. 1.134, 1.193
c. 1.134, 1.02
d. 1.034, 1.134
Answer : B

Question. The % by weight of NaOH solution is:
a. 4.34
b. 2.17
c. 5.28
d. 8.34
Answer : A

Question. The strength of NaOH solution is:
a. 30.44
b. 45.36
c. 39.44
d. 47.7
Answer : D

Question. The pH of NaOH solution is:
a. 13.9939
b. 0.0061
c. 12.0218
d. 14
Answer : D

Question. Volume of water required to prepare 1 litre 0.5 M solution of NaOH from V mL solution of NaOH: [V < 1000 mL]
a. 336 mL
b. 118 mL
c. 653 mL
d. 580 mL
Answer : D

Question. Number of molecules of NaOH present in its 10 mL solution is:
a. 6.023x10²³
b. 5.94x10²⁵
c. 6.023x10²⁰
d. 7.18x10²⁵
Answer : D

Question. The 10 mL NaOH solution is completely neutralized by 0.1 M H₂SO₄ . The volume of H₂SO₄ needed is:
a. 98.6 mL
b. 49.3 mL
c. 24.7 mL
d. 59.65 mL
Answer : D

1. What is stoichiometry?

 2. How much potassium chlorate should be heated to produce 2.24L of oxygen at NTP?

 3. Write an expression for molarity and molality of a solution.

4. Calculate the weight of lime (CaO) obtained by heating 2000kg of 95% pure lime stone (CaCO₃)

5. The substance which gets used up in any reaction is called --------------

6. What is 1molal solution?

7. 4 litres of water are added to 2L of 6 molar HCl solutions.

What is the molarity of resulting solution?

8. What volume of 10M HCl and 3M HCl should be mixed to obtain 1L of 6M HCl solution? 

Click on link below to download CBSE Class 11 Stoichiometry and Stoichiometric Calculations Worksheet A.