A 28.9 g sample of ethylene glycol, a car radiator coolant, loses 689 J of heat. What was the initial temperature of ethylene glycol if the final temperature is 32.5°C (c of ethylene glycol = 2.42 J/gK)?
q = 689 = mass coolant x specific heat x (Tfinal-Tinitial)
The only unknown is Ti
To find the initial temperature of ethylene glycol, you can use the formula for heat transfer:
Q = m * c * ΔT
Where:
Q is the amount of heat transferred
m is the mass of the substance
c is the specific heat capacity of the substance
ΔT is the change in temperature
In this case, you are given the following values:
Q = 689 J (amount of heat transferred)
m = 28.9 g (mass of ethylene glycol)
c = 2.42 J/gK (specific heat capacity of ethylene glycol)
ΔT = (final temperature - initial temperature)
You are asked to find the initial temperature (initial temperature = ?), which means you need to rearrange the formula:
ΔT = (final temperature - initial temperature)
Rearranging the formula, you get:
initial temperature = final temperature - ΔT
Substituting the given values into the formula, you have:
initial temperature = 32.5°C - ΔT
Now, to find ΔT, you can use the formula:
ΔT = Q / (m * c)
Substituting the given values into the formula, you have:
ΔT = 689 J / (28.9 g * 2.42 J/gK)
Calculating ΔT, you get:
ΔT = 9.47°C
Substituting this value back into the initial temperature formula, you have:
initial temperature = 32.5°C - 9.47°C
Calculating the initial temperature, you get:
initial temperature ≈ 23.03°C
So, the initial temperature of the ethylene glycol was approximately 23.03°C.