<u>Answer:</u> The amount of kilocalories contained in the given serving of crackes is 0.120 kCal
<u>Explanation:</u>
<u>As per the USDA:</u>
Carbohydrates provide 4 calories per gram, protein provides 4 calories per gram, and fat provides 9 calories per gram
We are given:
Mass of fat in the crackers = 4 g
Mass of carbohydrates in the crackers = 19 g
Mass of protein in the crackers = 2 g
Conversion factor used: 1 kCal = 1000 Cal
Applying unitary method:
1 gram of fat provides 9 calories
So, 4 gram of fat will provide = 
- <u>For Carbohydrates:</u>
1 gram of carbohydrates provides 4 calories
So, 19 gram of carbohydrates will provide = 
1 gram of proteins provides 4 calories
So, 2 gram of fat will provide = 
Total kilocalories per serving = [0.036 + 0.076 + 0.008] kCal = 0.120 kCal
Hence, the amount of kilocalories contained in the given serving of crackes is 0.120 kCal