A 25 g sample of a substance requires 25 calories to raise its temperature from 23 degrees C to 28 degrees C. What is the specific heat of the substance?
2007-06-20 04:47:23 · 5 answers · asked by RR Chic 1 in Science & Mathematics ➔ Chemistry
specific heat has units of calories/gram degree.
The equation that lets you calculate the specific heat is:
q=mcDT
where q is the amount of heat(calories, in your case), m is the mass of the sample, and DT is the change in temperature.
Your sample required 25 calories (q) to change 25 grams (m) by 5 degrees (DT). Plug those into the equation and solve for c.
2007-06-20 04:53:46 · answer #1 · answered by hcbiochem 7 · 0⤊ 0⤋
Q = mSÎt
here, Q = 25 cal.
m = 25 g
Ît = 28-23 = 5 º C
putting the values,
25 = 25*S*5
=> S= 1/5 = 0.2 cal/g ºC
2007-06-20 13:20:02 · answer #2 · answered by s0u1 reaver 5 · 0⤊ 0⤋
change in temperature=5ºC
mass=25g
Heat=25 calories=105J
heat capacity=105/(25*5)
=105/125
=0.84J/g/ºC
2007-06-20 11:55:41 · answer #3 · answered by Shy Lad 3 · 1⤊ 0⤋
energy = m x Cp x (T2-T1)
energy = 25 calories
Cp = heat capacity (ie specific heat)
T2 = 28C
T1 = 23 C
Cp = Energy / (m x (T2-T1))
= 25 cal / (25g x (28C -23C)) = 25 cal / (125 g x °C)
= 0.20 cal / g°C
cal/g°C is a valid unit for specific heat. you don't need to convert it to joules...
2007-06-20 12:23:11 · answer #4 · answered by Dr W 7 · 0⤊ 0⤋
0.2g/°c
this is because you need to find how many calories are needed to heat up one gram of the substance by one degree.
2007-06-20 12:34:46 · answer #5 · answered by Anonymous · 0⤊ 0⤋