Class 11 Some Basic Concepts of Chemistry MCQ with Answer

Class 11 chemistry MCQs with answers are provided here for Some Basic Concepts of Chemistry. These MCQs are based on the CBSE board curriculum and correspond to the most recent Class 11 chemistry syllabus. By practicing these Class 11 Multiple choice questions, students will be able to quickly review all of the ideas covered in the chapter and prepare for the Class 11 Annual examinations as well as other entrance exams such as NEET and JEE.

Class 11 Chemistry Some Basic Concepts of Chemistry MCQ with Answer

Q1. What will be the molarity of a solution, which contains 5.85g of NaCl(s) per 500mL?

  1. 4mol L-1
  2. 20mol L-1
  3. 0.2mol L-1
  4. 2mol L-1
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Q2. Zinc sulphate contains 22.65% zinc and 43.9% water of crystallisation. If the law of constant proportions is true
then the weight of zinc required to produce 20g of the zinc sulphate crystals will be:

  1. 45.3g.
  2. 4.53g.
  3. 0.453g.
  4. 453g.
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Ans: 2. 4.53g.

Q3. What will be the molality of the solution made by dissolving 10g of NaOH in 100g of water?

  1. 2.5m.
  2. 5m.
  3. 10m.
  4. 1.25m.
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Q4. Which of the following statements is/ are incorrect?

  1. The weight of a substance can be determined very accurately by using an analytical balance.
  2. Volume is denoted in dm units.
  3. Density of a substance is its amount present per unit volume.
  4. Candela is the luminous intensity, that emits monochromatic radiation of frequency, 540 × 1012 Hz.
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Ans: 1. The weight of a substance can be determined very accurately by using an analytical balance.

Q5. One mole of oxygen gas at STP is equal to _. 1 Mark

  1. 6.022 × 10 molecules of oxygen.
  2. 6.022 × 10 atoms of oxygen.
  3. 16g of oxygen.
  4. 32g of oxygen.
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Ans: 1. 6.022 × 10 molecules of oxygen.

  1. 4. 32g of oxygen.

Q6. 0.2429g sample of potassium is heated in oxygen, 0.440g of a crystalline compound is obtained. What is the
formula of this compound?

  1. KO
  2. K2O
  3. KO2
  4. KO3
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Q7. What is the mass percent of carbon in carbon dioxide?

  1. 0.034%
  2. 27.27%
  3. 3.4%
  4. 28.7%
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Q8. 1g of M2CO3 on treatment with excess HCl produces 0.01186 moles of CO2 The molar mass of M2CO3 in g mor-1
is:

  1. 1186
  2. 84.3
  3. 118.6
  4. 11.86
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Q9.

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Q10. The result reported in the following multiplication of significant figures,
2.5 × 1.25 = 3.125 should be:

  1. 3.125
  2. 3.1
  3. 3.12
  4. 3.10
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Ans: 2. 3.1

Explanation:
2.5 × 1.25 = 3.125
Since, 2.5 has two significant figures, the result should not have more than two significant figures thus, it is 3.1.

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Q12. What is mass silicon in 100g of sodium silicate, Na2SiO3 ?

  1. 16.7%
  2. 23.0%
  3. 28.0%
  4. 82.0%
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Q13. The number of atoms present in one mole of an element is equal to Avogadro number. Which of the following
element contains the greatest number of atoms?

  1. 4g He
  2. 46g Na
  3. 0.40g Ca
  4. 12g He
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Q14. Which of the following solutions have the same concentration?

  1. 20g of NaOH in 200mL of solution.
  2. 0.5mol of KCl in 200mL of solution.
  3. 40g of NaOH in 100mL of solution.
  4. 20g of KOH in 200mL of solution.
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Q15. How many number of aluminium ions are present in 0.051g of aluminium oxide?

  1. 6.023 × 1023 ions.
  2. 3 ions.
  3. 6.023 × 1020 ions.
  4. 9 ions.
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Ans: 3. 6.023 × 1020 ions.

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Q18. The solution of A and B are 0.1 and 0.2 molar in a substance. If 100ML of ‘A’ are mixed with 25mL of B and there
is no change in volume, then the final molarity of solution is:

  1. 0.15M
  2. 0.18M
  3. 0.12M
  4. 0.30M
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Ans: 3. 0.12M

Q19. One of the statements of Dalton’s atomic theory is given below:
“Compounds are formed when atoms of different elements combine in a fixed ratio”
Which of the following laws is not related to this statement?

  1. Law of conservation of mass.
  2. Law of definite proportions.
  3. Law of multiple proportions.
  4. Avogadro law.
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Ans: 1. Law of conservation of mass.

  1. Avogadro law.
    Explanation:
    Law of conservation of mass states that matter can neither be created nor destroyer. Avogadro proposed that equal volumes of gases
    at the same teprerature and pressure should contain equal number of molecules.

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Ans: 3. An element forms two oxides, XO and XO2 containing 50% and 60% oxygen respectively. The ratio of masses of oxygen which
combines with 1g of element X is 2 : 3.

Q21. If the density of a solution is 3.12g mL-1 , the mass of 1.5mL solution in significant figures is _.

  1. 4.7g
  2. 4680 × 10–3gClick To View The Answer
  3. 4.680g
  4. 46.80g
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Q22. The weight of iron which will be converted into its oxide (Fe3 O4 ) by the action of 18g of steam on it will be
(Atomic weight of Fe = 56).

  1. 168g.
  2. 84g.
  3. 42g.
  4. 21g.
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Ans: 3. 42g


Q23. How many number of molecules and atoms respectively are present in 2.8L of a diatomic gas at STP?

  1. 6.023 × 1023 , 7.5 × 1023
  2. 6.023 × 1023 , 15 × 1022
  3. 7.5 × 10 , 15 × 1022
  4. 15 × 10 , 7.5 × 1023
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Ans: 3. 7.5 × 10 , 15 × 1022

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Q25. A gas is found to have the formula (CO)x . Its vapour density is 70. The value of x will be:

  1. 7
  2. 4
  3. 5
  4. 6
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Ans: 3. 5

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Ans: 1. Total mass of iron and oxygen in reactants = total mass of iron and oxygen in product therefore it follows law of conservation of
mass

Q27. The mass of one mole a chloride formed by metal ‘X’ is 111.0g. Which one could be formula of chloride?

  1. XCl
  2. XCl2
  3. XCl3
  4. XCl4
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Ans: 2. XCl2

Q28. A measured temperature on Fahrenheit scale is 200°F. What will this reading be on Celsius scale?

  1. 40°C
  2. 94°C
  3. 93.3°C
  4. 30°C
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Q29. Which law states that if two elements can combine to form more than one compound, the masses of one
element that combine with a fixed mass of other element, are in the ratio of small whole numbers?

  1. Avogadro’s law.
  2. Law of definite composition.
  3. Law of multiple proportions.
  4. Gay Lussac’s law of gaseous volumes.
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Ans: 3. Law of multiple proportions.

Q30. Which set of figures will be obtained after rounding upto three significant figures 1.386, 4.334, 2.808?

  1. 1.39, 4.34, 2.809
  2. 1.39, 4.33, 2.81
  3. 1.38, 4.34, 2.800
  4. 1.39, 4.34, 2.80
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Ans: 2. 1.39, 4.33, 2.81