What is the specific heat capacity of a 17.5g sample of an unknown metal that
releases 6700J of heat when it cools from 90 to 25 degrees C?

90°c

Explanation:

Rearrange the formula above to isolate

. Insert your data into the formula and solve.

answer: enthalpy

explanation:

for a exothermic reaction, the energy is released i.e. the energy of the products is lower than the energy of the reactants.

= enthaply

= energy of products

= energy of reactants

as , thus comes out to be negative. negative value of enthalpy shows that the reaction is exothermic.

i believe you are right for all except the 3rd ( look at sqdancefan his answer is much better)