Question

a slice of bread has 1.5 g of fat, 19 g carbohydrate and 4 g protein. how many kcal in the slice? please show all of you work in a dimensional analysis format.

Answer 1

The answer is 105.5 kcal/slice of bread.

Explanation:

The kcal per gram of:

• protein = 4kcal/g.
• carbohydrate = 4kcal/g.
• fat = 9kcal/g.

Now, you have:

• 1.5 g of fat + 19g of carbohydrate + 4g of protein = 1 slice of bread.

If we multiply the amount of components by his kcal:

• 1.5g * 9kcal/g + 19g * 4kcal/g + 4g * 4kcal/g;

Now gram/gram = 1, and we can cancel the grams in the equation:

• 1.5* 9kcal + 19 * 4kcal + 4 * 4kcal = 105.5kcal;

Finally, the result of the kcal of the slice bread is:

• 105.5 kcal/slice of bread.