calculate the mass of the graphite that must be burned to produce 0.0264 kg of carbon dioxide.\na 7.2…

Explanation:

Step1: Write the chemical equation

The combustion of graphite (carbon) is $C + O_2\rightarrow CO_2$.

Step2: Convert mass of $CO_2$ to moles

The molar mass of $CO_2$ is $M_{CO_2}=12 + 2\times16=44\ g/mol$. The mass of $CO_2$ is $m = 0.0264\ kg=26.4\ g$. The number of moles of $CO_2$, $n_{CO_2}=\frac{m}{M}=\frac{26.4\ g}{44\ g/mol}=0.6\ mol$.

Step3: Determine moles of C

From the balanced - chemical equation, the mole ratio of $C$ to $CO_2$ is $1:1$. So, the number of moles of $C$, $n_C=n_{CO_2}=0.6\ mol$.

Step4: Calculate mass of C

The molar mass of $C$ is $M_C = 12\ g/mol$. The mass of $C$, $m_C=n_C\times M_C=0.6\ mol\times12\ g/mol = 7.2\ g$.

Answer:

A. 7.2 grams