Question

$CaC{o_3}$ is $90\%$ pure volume of $C{O_2}$ collected at STP when $10{\text{ }}gram$ of $CaC{O_3}$ is decomposed is:
A.$\;2.0{\text{ }}16{\text{ }}liters$
B.$1.008{\text{ }}liters$
C.$10.08{\text{ }}liters$
D.$\;20.16{\text{ }}liters$

Answer 1

In the given question we have to find out the decomposed calcium carbonate according to the value of standard temperature and volume. Initially we will have to solve by using the concept of moles. After finding the moles of each we can easily find out the volume.

Complete Step by step answer: The ideal gas law in the chemistry states that the volume engaged by a gas depends upon the amount of substance (which is gas) as well as temperature and on pressure. And the value of Standard temperature and standard pressure is usually abbreviated by the term $STP$ and has values such as $0$ degrees Celsius and $1$ atmosphere of pressure.
According to question the reaction occurs is $CaC{O_3} \to {\text{ }}CaO + C{O_2}$
From the reaction the gas produced is $C{O_2}$
Therefore,
1{\text{ }}\;mol\;$$$$CaC{O_3} produces 1{\text{ }}\;mol$$$$C{O_2}
So, we have $\dfrac{{90}}{{100}}{\text{ }} \times {\text{ }}10{\text{ }} = {\text{ }}9g{\text{ }}$ pure $CaC{O_3}$
Molar mass of $CaC{O_3} = 100g/mol$
So, $9g{\text{ }}CaC{O_3} = {\text{ }}9100{\text{ }} = {\text{ }}0.09{\text{ }}mol{\text{ }}CaC{O_3}$
This will produce $0.09{\text{ }}\;mol{\text{ }}C{O_2}$
At $STP{\text{ }}1 mol{\text{ }} = {\text{ }}22.4L$
$0.09\;mol{\text{ }} = {\text{ }}0.09{\text{ }}x{\text{ }}22.4{\text{ }} = {\text{ }}2.016L$
Hence, the volume of $C{O_2}$ collected at STP when $10{\text{ }}gram$ of $CaC{O_3}$ is decomposed is $2.0L$

Hence the correct option is A.

Note: The standard temperature and pressure or we can say $STP$ is said to be a system which have a temperature value of zero degrees centigrade that is $273$ Kelvin and the pressure value is equal to the atmosphere will always be $1$ atm. as well, one mole of any gas at STP value occupies a volume of about $22.414{\text{ }}Litre$. Though the concept of standard temperature and volume only takes place for the true gases only.