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Question: In which case, purity of the substance is \( 100\% \) ? (A) \( 1{\text{ mole of CaC}}{{\text{O}}_3...

In which case, purity of the substance is 100%100\% ?
(A) 1 mole of CaCO3 gave 11.2L CO2 (at STP)1{\text{ mole of CaC}}{{\text{O}}_3}{\text{ gave 11}}{\text{.2L C}}{{\text{O}}_2}{\text{ (at STP)}}
(B) 1 mole of MgCO3 gave 40.0g MgO1{\text{ mole of MgC}}{{\text{O}}_3}{\text{ gave 40}}{\text{.0g MgO}}
(C) 1 mole of NaHCO3 gave 4g H2O 1{\text{ mole of NaHC}}{{\text{O}}_3}{\text{ gave 4g }}{{\text{H}}_2}{\text{O }}
(D) 1 mole of Ca(HCO3)2 gave 1 mole CO2 1{\text{ mole of Ca(HC}}{{\text{O}}_3}{{\text{)}}_2}{\text{ gave 1 mole C}}{{\text{O}}_2}{\text{ }}

Explanation

Solution

Hint : The absence of impurities or types of matter other than the substance itself is called purity. There are many tests to check the purity of a substance. To solve this problem, we have to write the chemical reactions and find mole ratios.

Complete Step By Step Answer:
Assume that all the given compounds are 100%100\% pure. So, 1 mole of CaCO31{\text{ mole of CaC}}{{\text{O}}_3} should give 22.4L CO2 (at STP){\text{22}}{\text{.4L C}}{{\text{O}}_2}{\text{ (at STP)}} . This is determined from the stoichiometric ratio of moles of reactant to moles of carbon dioxide. Write a chemical equation and find the ratio of moles of calcium carbonate to carbon dioxide. 1 mole of MgCO31{\text{ mole of MgC}}{{\text{O}}_3} should give 40.0 g MgO40.0{\text{ g MgO}} . 22.4L CO2 (at STP){\text{22}}{\text{.4L C}}{{\text{O}}_2}{\text{ (at STP)}} . This is determined from the stoichiometric ratio of moles of reactant to moles of magnesium oxide. Write a chemical equation and find the ratio of moles of magnesium carbonate to magnesium oxide. 1 mole of NaHCO31{\text{ mole of NaHC}}{{\text{O}}_3} should give 9 g H2O9{\text{ g }}{{\text{H}}_2}{\text{O}} . This is determined from the stoichiometric ratio of moles of reactant to moles of water. Write a chemical equation and find the ratio of moles of NaHCO3NaHC{O_3} to water. 1 mole of Ca(HCO3)21{\text{ mole of Ca(HC}}{{\text{O}}_3}{)_2} should give 2 moles CO22{\text{ moles C}}{{\text{O}}_2} . This is determined from the stoichiometric ratio of moles of reactant to moles of carbon dioxide. Write a chemical equation and find the ratio of moles of Ca(HCO3)2{\text{Ca(HC}}{{\text{O}}_3}{)_2} to carbon dioxide.
Therefore, option B is the correct answer.

Note :
Percentage purity is calculated by dividing the mass of the pure chemical by the total mass of the sample given and then multiplying the result by 100100 . The percent yield is defined as the ratio of the actual yield to the theoretical yield expressed in the percentage form.