How many kcal are needed to raise the temperature of 120 g of water from 15°C to 75°C?

hi

Q=.120kg*cw*(75-15) watch your units on cw, you want as I have laid it out in kcal/kgC (I think it is 1000,look it up)

To calculate the amount of energy (in kilocalories or kcal) needed to raise the temperature of a substance, you can use the following formula:

Q = m * C * ΔT

Where:
Q is the energy in kcal,
m is the mass of the substance in grams,
C is the specific heat capacity of the substance (in this case, water),
ΔT is the change in temperature.

For water, the specific heat capacity is approximately 1 calorie per gram per degree Celsius (1 cal/g°C) or 1 kcal/kg°C.

Now let's calculate it for your case:

m = 120 g (mass of water)
C = 1 kcal/kg°C (specific heat capacity of water)
ΔT = 75°C - 15°C = 60°C (change in temperature)

Plugging these values into the formula, we get:

Q = m * C * ΔT
Q = 120 g * 1 kcal/kg°C * 60°C
Q = 7200 kcal

Therefore, it would require 7200 kcal of energy to raise the temperature of 120 g of water from 15°C to 75°C.