A copper coin with a mass of 6.30 grams changes temperature in the sunshine from 20.0°C to 32.0°C. How much energy is transferred? The specific heat capacity of copper is 0.377 joules/gram degree Celsius. Express your answer to three significant figures. The amount of energy transferred to the coin is
joules.

q = mC∆T

q = heat = ?

m = mass = 6.30 g

C = specific heat = 0.385 J/g/deg

∆T = change in temperature = 32-20 = 12º

q = ((6.30 g)(0.385 J/g/deg)(12 deg) = 29.1 J (to 3 significant figures)

Explanation:

answer: the enthalpy of the overall chemical reaction is +87.88 kj or +88 kj.

according to hess's law, the overall enthalpy of a reaction is the difference between the sum of enthalpy values of all the products and the sum of enthalpy values of all the reactants.

δh(reaction) = ∑nδh(products) - ∑nδh(reactants)

δh(reaction) = [δh +δh] - [δh]

δh(reaction) = [1(-287.02) + 1(0) ] - [1(-374.9)] kj = +87.88 kj

here, δh (pcl3) = -287.02 kj, δh(cl2) = 0, δh(pcl5) = -374.9 kj

therefore, enthalpy of the overall reaction is +87.88 kj or +88 kj.