A serving of potato chips is crushed and burned in a clorimeter. the calorimeter has 2000 grams of water in it and the initail temperature is 21.0 degrees celsius. If the water's temperature increases to 29.0 degrees celsius, how many calories (kilocalories) are in the chips? I know that 1 calorie is 4.18 J. And i'm pretty sure you use the q=mcdeltaT formula.
you have to convert the q(energy) that you find to calories.
Yes, you use mcdeltaT.
I wouldn't go through the 4.184 step since we know that the specific heat of water is 1 cal/g*C or 4.184 J/g*C.
This will give you calories and you divide by 1000 to obtain kcal BUT you call it BIG calories (or just calories or Calories---with a capital C) or some such word since the food business uses kcal = 1 cal. Some are trying to change that.
So 2000 x 1 x 8 = 16,000 cal = 16 kcal = 16 cal in the food business.
Yes, you are correct. The formula you mentioned, q = mcΔT, is used to calculate the amount of heat transferred, where q represents heat energy, m represents mass, c represents specific heat capacity, and ΔT represents the change in temperature.
In this case, we can calculate the heat energy released by the burning potato chips by using the mass of water in the calorimeter (m), the specific heat capacity of water (c), and the change in temperature (ΔT).
Given:
Mass of water (m) = 2000 grams
Initial temperature (T1) = 21.0 degrees Celsius
Final temperature (T2) = 29.0 degrees Celsius
Specific heat capacity of water (c) = 4.18 J/g°C
First, let's convert the mass of water to kilograms to match the units of specific heat capacity (J/g°C):
Mass of water (m) = 2000 grams = 2000/1000 = 2 kilograms
Now, we can calculate the change in temperature (ΔT):
ΔT = T2 - T1 = 29.0°C - 21.0°C = 8.0°C
Next, we can calculate the heat energy (q) released by the burning chips using the formula:
q = mcΔT
q = (mass of water) x (specific heat capacity of water) x (change in temperature)
= 2 kg x 4.18 J/g°C x 8.0°C
Now, let's perform the calculation:
q = 2 x 4.18 x 8.0 = 66.88 J
Since the specific question asks for calories (kilocalories), we need to convert the heat energy from joules to kilocalories. Remember that 1 calorie = 4.18 J, and 1 kilocalorie = 1000 calories.
Therefore, the heat energy in kilocalories (calories) would be:
66.88 J / 4.18 J/calorie = 16.0 calories
16.0 calories / 1000 = 0.016 kilocalories (rounded to 3 decimal places)
Hence, the amount of calories (kilocalories) in the chips is approximately 0.016 kilocalories.