# Difference between q=m delta H and q=mC delta T?

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#1
I'm getting a little mixed up with the formulas and what problems to use them for. I thought that q=m delta H was only used to find the amount of energy needed to heat, freeze, and boil H20, and q=mc delta T was used to find the amount of heat needed to heat something up. I had a chem problem which asked me to find the amount energy required to raise the temperature of 1.0 mol of Ag, but the information given was similar to the q=mC delta T formula, even though I was looking for the amount of energy, not amount of heat. I looked online, and everyone used the q=mC delta T formula, which made sense, but now I'm a bit confused on the difference between the two and which problems to use the formulas for. A little help please? Thank you!!
0
3 years ago
#2
(Original post by ml232)
I'm getting a little mixed up with the formulas and what problems to use them for. I thought that q=m delta H was only used to find the amount of energy needed to heat, freeze, and boil H20, and q=mc delta T was used to find the amount of heat needed to heat something up. I had a chem problem which asked me to find the amount energy required to raise the temperature of 1.0 mol of Ag, but the information given was similar to the q=mC delta T formula, even though I was looking for the amount of energy, not amount of heat. I looked online, and everyone used the q=mC delta T formula, which made sense, but now I'm a bit confused on the difference between the two and which problems to use the formulas for. A little help please? Thank you!!
0
3 years ago
#3
(Original post by ml232)
I'm getting a little mixed up with the formulas and what problems to use them for. I thought that q=m delta H was only used to find the amount of energy needed to heat, freeze, and boil H20, and q=mc delta T was used to find the amount of heat needed to heat something up. I had a chem problem which asked me to find the amount energy required to raise the temperature of 1.0 mol of Ag, but the information given was similar to the q=mC delta T formula, even though I was looking for the amount of energy, not amount of heat. I looked online, and everyone used the q=mC delta T formula, which made sense, but now I'm a bit confused on the difference between the two and which problems to use the formulas for. A little help please? Thank you!!
They are the same formula, just in different form. You do however need to understand, that "c" in the formula, stands for specific heat capacity, which is the energy needed to change the temperature of 1g of any matter, by 1 degree celcius. So, if a certain temperature change is recorded, you can directly find the change in enthalpy, by multiplying the change in temperature with specific heat capacity. For me, I find that the later formula is much useful, because you could understand where you could calculate the change in enthalpy. Hope it clears up the problem
0
3 years ago
#4
(Original post by Aliff)
They are the same formula, just in different form. You do however need to understand, that "c" in the formula, stands for specific heat capacity, which is the energy needed to change the temperature of 1g of any matter, by 1 degree celcius. So, if a certain temperature change is recorded, you can directly find the change in enthalpy, by multiplying the change in temperature with specific heat capacity. For me, I find that the later formula is much useful, because you could understand where you could calculate the change in enthalpy. Hope it clears up the problem
Err no they aren't, q = mH is energy needed for phase changes to occur.
0
3 years ago
#5
(Original post by Vikingninja)
Err no they aren't, q = mH is energy needed for phase changes to occur.
Well, the way that op wrote it, is q=m*delta H, so from that, I thought that the op is trying to differentiate between delta H and c*delta T.

if it is not the delta H formula, try and use q=m*L okay op, instead of q=mH, because L stands for the different specific latent heat (vaporistion= liquid to gas, fusion= solid to liquid) required to change the state.
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