1. How many joules of energy must be absorbed to raise the temperature of 20 grams of water from 25°C to 30°C?
q = mass x specific heat x delta T
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To find the amount of energy (joules) required to raise the temperature of a substance, you need to use the specific heat capacity formula, which is:
Q = m * c * ΔT
Where:
Q is the heat energy (in joules)
m is the mass of the substance (in grams)
c is the specific heat capacity of the substance (in J/g°C)
ΔT is the change in temperature (in °C)
In this case, you have:
m = 20 grams (mass of water)
c = 4.18 J/g°C (specific heat capacity of water)
ΔT = 30°C - 25°C = 5°C (change in temperature)
Now, substitute the given values into the formula to calculate the energy required:
Q = 20 grams * 4.18 J/g°C * 5°C
Q = 418 joules
Therefore, to raise the temperature of 20 grams of water from 25°C to 30°C, 418 joules of energy must be absorbed.