1 g of an impure sample of calcium carbonate (containing no thermally decomposable impurities) on complete thermal decomposition gave 0.33 g of carbon dioxide gas. The percentage of impurity in this sample is (Atomic masses of C , O and Ca are respectively 12,16 and 40 g mol-1 )

Question

1 g of an impure sample of calcium carbonate (containing no thermally decomposable impurities) on complete thermal decomposition gave 0.33 g of carbon dioxide gas. The percentage of impurity in this sample is (Atomic masses of C , O and Ca are respectively 12,16 and 40 g mol-1 ) (A)  25  (B)  20  (C)  30  (D)  33

Tardigrade Admin · Accepted Answer

underset text100 gCaCO3 xrightarrowΔ CaO+ underset text 44 gCO2 44 g of CO2 is obtained from 100 g of CaCO3 ∴ 0.33 g of CO2 is obtained from (100/44)× 0.33 =0.75 g of CaCO3 ∴ Percentage of impurity in the sample of CaCO3 is 25 %

$25$

$20$

$30$

$33$

$100 g C a C O_{3} Δ C a O + 44 g C O_{2}$
$44 g$ of $C O_{2}$ is obtained from $100 g$ of $C a C O_{3}$
$∴ 0.33 g$ of $C O_{2}$ is obtained from $\frac{100}{44} \times 0.33$
$= 0.75 g$ of $C a C O_{3}$
$∴$ Percentage of impurity in the sample of $C a C O_{3}$ is $25%$

Q. 1g of an impure sample of calcium carbonate (containing no thermally decomposable impurities) on complete thermal decomposition gave 0.33g of carbon dioxide gas. The percentage of impurity in this sample is (Atomic masses of C , O and Ca are respectively 12,16 and 40gmol−1 )

25

20

30

33

100 gCaCO3​​Δ​CaO+44 gCO2​​ 44g of CO2​ is obtained from 100g of CaCO3​ ∴0.33g of CO2​ is obtained from 44100​×0.33 =0.75g of CaCO3​ ∴ Percentage of impurity in the sample of CaCO3​ is 25%

$25$

$20$

$30$

$33$

$100 g C a C O_{3} Δ C a O + 44 g C O_{2}$
$44 g$ of $C O_{2}$ is obtained from $100 g$ of $C a C O_{3}$
$∴ 0.33 g$ of $C O_{2}$ is obtained from $\frac{100}{44} \times 0.33$
$= 0.75 g$ of $C a C O_{3}$
$∴$ Percentage of impurity in the sample of $C a C O_{3}$ is $25%$