Q. 15.77 - An Introduction to General, Organic, and Biological Chemistry

Question

The total kilocalories and grams of fat for some typical meals at fast-food restaurants are listed here. Calculate the number of kilocalories and the percentage of total kilocalories from fat $(1 gram = 9 kcal)$. Round answers to the tens place.

a. a chicken dinner, $830 kcal, 46g$ of fat

b. a quarter-pound cheeseburger, $520 kcal, 29g$of fat

c. pepperoni pizza (three slices), $560 kcal, 18g$ of fat

Step-by-Step Solution

Answer

(part a) The percentage of total kilocalories from fat  $49\%$

(part b) The percentage of total kilocalories from fat  $50\%$

(part c) The percentage of total kilocalories from fat  $29\%$

Step 1: Introduction (part a)

Lipids contain found naturally molecules such as fats, waxes, and sterols. triglycerides, for illustration Cholesterol are fats that have included glycerol bonded to three fatty acids, such like fats and oils.  

Step 2: Given Information (part a)

Supper over chicken, $830 kcal, 46g$ of fat .

Step 3: Explanation (part a)

Number of kilocalories -

$1$ gram of fat produces $9kcal$

$46$ grams of fat produce

$=46 g\times 9kcal$

$=414 kcal$

$=410 kcal$ (roundoff)

The total kilocalories produce from $46 g$of fat $=410 kcal$

Supper with chicken leftovers$830 kcal$

$=410/830\times 100$

$=49\%$

The percentage of kilocalories from fat $=49\%$

Step 4: Given Information (part b)

A quarter-pound cheeseburger, $520 kcal, 29g$of fat.

Step 5: Explanation (part b)

Number of kilocalories -

 $1$gram of fat produces $9kcal$

  $29$grams of fat produce

$=29 g\times 9kcal$

$=261 kcal$

$=260$ (roundoff)

The total kilocalories produce from of fat 

The total kilocalories produce from 

Fat content as a portion of overall energy

$=260/8520\times 100$

$=50\%$

The percentage of kilocalories from fat $=50\%$

Step 6: Given Information (part c)

Pepperoni pizza (three slices),  $560 kcal, 18g$of fat.

Step 7: Explanation (part c)

Number of kilocalories -

$1$ gram of fat produces $9kcal$

 $18$ grams of fat produce

$=18 g\times 9kcal$

$=162 kcal$

 $= 160 kcal$(roundoff)

The total kilocalories produce from of fat 

The total kilocalories produce from 

Fat content as a portion of overall energy

$=160/560\times 100$

$=29\%$

The percentage of kilocalories from fat $29\%$