In kaplan book q=mc delta T but in the textbook, the equation is q=nc delta T. which one is correct? or they are the same?
Then q=m delta Hfusion or q=m delta H fusion?
Help please
q=mc delta T is right. m stands for mass.
The second equation you gave, q=nc delta T is only correct if you multiply n my the molar mass. n, which I'm assuming to be the number of moles, times the molar mass, gives you just plain grams. This is what you wanted all along: a value for m. So if they give you a value for m, like something in grams, then plug it directly into the equation. If they give you something in moles, then multiply it by molar mass to get grams, then plug it into the equation.
The second part of your question: fusion is when you go from a solid to a liquid. That is called fusion, or melting. But you don't say heat of melting. You say: "Heat of fusion," which is the amount of enthalpy required to melt that substance. That value is always positive. Same thing with heats of vaporization -- always positive (endothermic). You're putting energy into the system. Neither of those equations are right though, I don't think. q is simply change in H when q is at constant pressure. So the correct equation should look like this: q= Δ
Hfus ,assuming that q is at constant pressure and q is an accurate representation of heat flow, in joules per mole, just as Δ
Hfus is in joules per mole.
