(a) A serving of a particular ready-to-serve brown \& wild rice meal contains \(4.5 \mathrm{~g}\) fat, \(42 \mathrm{~g}\) carbohydrate, and \(4.0 \mathrm{~g}\) protein. Estimate the number of calories in a serving. (b) According to its nutrition label, the same meal also contains $140 \mathrm{mg}$ of potassium ions. Do you think the potassium contributes to the caloric content of the food?

Using the given amounts of each nutrient, we will calculate the number of calories contributed by each. (a) Calories from fat: The meal contains 4.5 g of fat, and 1 g of fat provides 9 calories. Therefore, \(calories_{fat} = 4.5g \times 9 \frac{cal}{g} = 40.5 cal\). Calories from carbohydrates: The meal contains 42 g of carbohydrate, and 1 g of carbohydrate provides 4 calories. Therefore, \(calories_{carbohydrate} = 42g \times 4 \frac{cal}{g} = 168 cal\). Calories from protein: The meal contains 4.0 g of protein, and 1 g of protein provides 4 calories. Therefore, \(calories_{protein} = 4g \times 4 \frac{cal}{g} = 16 cal\). Now let's add up the calories from each nutrient to find the total number of calories in a serving of the meal.

To calculate the total number of calories, we will add the calories obtained from fat, carbohydrate, and protein nutrients: Total calories = Calories from fat + Calories from carbohydrates + Calories from protein Total calories = 40.5 cal + 168 cal + 16 cal = 224.5 cal So, the total number of calories in a serving of this meal is approximately 224.5 calories. (b) Do you think the potassium contributes to the caloric content of the food? Potassium is a micronutrient, and it does not provide any calories. Hence, the potassium content in the meal does not contribute to the caloric content of the food.