Question

Convert each of the following energy units:

a. 8.1 kcal to cal

b. 325 J to KJ

c. 2550 cal to KJ

d. 2.5 kcal to J

Short answer

(part a) $8100cal$

(part b) $0.325kJ$

(part c) $10.7kJ$

(part d ) $10460J$

Step-by-step solution

 (Part a) Step 1: Given Information

The given value is$8.1kcal$

To convert$\text{8.1kcal to cal}$by the appropriate method

 (Part a) Step 2: Explanation

For converting $\text{8.1kcal}$to calories we have-

Using $1\mathrm{kcal}=1000\mathrm{cal}$,

Hence for$8.1kcal$,$8.1kcal$

localid="1654281933746" $$\begin{gathered} =8.1\times 1000 \\ =8100cal \end{gathered}$$

 (Part b) Step 3: Given Information

The given value is $325J$

To convert $325\mathrm{J}\text{tokJ}$by the appropriate method

(Part b) Step 4: Explanation 

For converting $325\mathrm{J}\text{tokJ}$we have-

Using,$1\mathrm{kJ}=1000\mathrm{J}$

Hence for $325J$,

$$\begin{gathered} =\frac{325}{1000} \\ =0.325kJ \end{gathered}$$

 (Part c ) Step 5: Given Information

The given value is$2550cal$

To convert$2550\mathrm{cal}\text{tokJ}$by the appropriate method.

(Part c) Step 6: Given Information 

For converting $2550\mathrm{cal}\text{tokJ}$we have,

Using $1\mathrm{kcal}=4.184\mathrm{kJ}$and $1\mathrm{kcal}=1000\mathrm{cal}$,

Hence for $2550cal$,

$$\begin{gathered} =2550\times \frac{4.184}{1000} \\ =10.7J \end{gathered}$$

 (Part d)  Step 7: Given Information

The given value is $2.5\mathrm{kcal}$

To convert$2.5\mathrm{kcal}\text{to}\mathrm{J}$using the appropriate method.

(Part d) Step 8: Given Information 

For converting $2.5\mathrm{kcal}\text{to}\mathrm{J}$we have,

Using $1\mathrm{kcal}=1000\mathrm{cal}$and $1\mathrm{cal}=4.184\mathrm{J}$,

Hence for $2.5kcal$,

$$\begin{gathered} =2.5\times 4.184\times 1000 \\ =10460J \end{gathered}$$