Can somebody please help me with this question? That'd be great. Thanks!
Determine the amount of heat needed in the following:
the number of calories to heat 25 grams of water from 22 degrees celcius to 44 degrees celcius.
Q= m c deltaTemp
= 25g*1cal/gC*(44-22)C
=25*22 calories. If you want it in other units, either convert, or use the specific heat in those units.
Thank you! I have a problem that asks for the number of joules. Should I do it in calories first and convert it to joules?
As Bob Pursley pointed out to you in his post, you may use 1 cal/g*C, then convert to Joules knowing that 1 cal = 4.184 joules OR you may use 4.184 joules/g*C in place of the 1 cal in the calculations (for specific heat) of q = mcdeltaT and get the joules directly.
Yes, you can first calculate the heat in calories and then convert it to joules. Here's how:
1. Start with the formula for calculating heat:
Q = m * c * deltaT
Q = heat (in calories)
m = mass (in grams)
c = specific heat capacity (in cal/g°C)
deltaT = change in temperature (in °C)
2. Plug in the values for the given parameters:
m = 25 grams
c = 1 cal/g°C (or you can use 4.184 joules/g°C if you want to get the answer in joules)
deltaT = 44°C - 22°C = 22°C
Q = 25 g * 1 cal/g°C * 22°C
Q = 550 calories
3. If you want to convert the answer from calories to joules, you can use the conversion factor that 1 calorie is equal to 4.184 joules. Multiply the heat in calories by this conversion factor:
Q = 550 calories * 4.184 joules/calorie
Q ≈ 2299.2 joules
So, the amount of heat needed is approximately 2299.2 joules.