From the complete decomposition of 20g CaCO3 at STP the volume of CO2 obtained is:

Correct answer: C. 4.48dm3

  • A. 2.24dm3
  • B. 44.8dm3
  • C. 4.48dm3
  • D. 48.4dm3

Explanation

Balanced equation of decomposition of CaCO3: CaCO3 (s) → CaO (s) + CO2 (g) mass of CaCO3 : 20g molecular mass of CaCO3 : (1 x 20) + (1 x 12) + (3 x 16) = 100 no. of moles of CaCO3 : 20 / 100 = 0.2 moles stoichiometry ratio of CaCO3 : CO2 = 1 : 1 no. of moles of CO2 = 0.2 volume of 1 mol of CO2 at S.T.P = 22.4 dm3 volume of 0.2 mol of CO2 at S.T.P = 0.2 x 22.4 = 4.48 dm3 Thus option C is correct.

Written and checked by , M.Phil ChemistryLast updated
Report an error

The more specific you are, the faster it gets fixed. A source beats an opinion.

Prefer email? [email protected]

About Fundamental Concepts of Chemistry

Mole calculations connect mass, number of particles and Avogadro's number, while balanced equations provide the mole ratios used in stoichiometry. Questions cover limiting and excess reactants, theoretical yield and percentage yield, including identifying which reactant is consumed first and comparing the actual product with the maximum possible product.

Practise Fundamental Concepts of Chemistry

894 free Fundamental Concepts of Chemistry MCQs from Chemistry, each with the correct answer and an explanation. Unlimited attempts, no account needed.

Discussion

Stuck on an option, or know a faster way to get there? Ask or explain it here.

No comments yet. Be the first to explain this one.

Exams that ask Chemistry questions like this

Chemistry is on 14 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.

More Fundamental Concepts of Chemistry questions