Q. 3.86 - An Introduction to General, Organic, and Biological Chemistry

Question

A $1.3-\mathrm{g}$ sample of rice is placed in a calorimeter. When the sample is burned, $22\mathrm{kJ}$ is given off. What is the energy value $(\mathrm{kcal}/\mathrm{g})$ for the rice? 

Step-by-Step Solution

Answer

The energy value of rice is $4.1\mathrm{kcal}/\mathrm{g}$burning a sample in a calorimeter.

Step: 1 Given Information:

Given data are:$1.3\mathrm{g}$ of sample rice in calorimeter and $22\mathrm{kJ}$energy values.

To find the food's energy value by burning a sample in a calorimeter in $\mathrm{kcal}/\mathrm{g}$.

Step: 2 Finding Energy Value:

Energy given by $1\mathrm{g}$of rice

$=1\mathrm{g}\text{ rice }\times \frac{22\mathrm{kJ}}{1.3\mathrm{g}}$

$=17\frac{\mathrm{kJ}}{\mathrm{g}}\times \frac{1\mathrm{kcal}}{4.184\mathrm{kJ}}$

$=4.1\mathrm{kcal}/\mathrm{g}$

As a result,the energy value of rice is $4.1\mathrm{kcal}/\mathrm{g}.$