Consider the following reaction in which all reactants and products are gases. P4+6Cl2⟶4PCl3
A 100. mL reactor vessel is charged with 250. mg of P4 and 4.21 atm of Cl2 at 298 K. The reaction goes to completion.
How many moles of chlorine gas are initially in the vessel?

 The quantity of heat produced by the reaction is +26710.656J

Explanation:

Quantity of Heat, Q = mass * specific heat capacity *temperature change

Q = mCpTc, where m= mass, Cp= specific heat capacity, Tc is temperature change

m= 210.0g, Cp=4.184J/(g · oC), Tc= 57.6 - 27.2 = 30.4 oC

Q = 210.0g *4.184J/(g · oC) * 30.4 oC

Q = +26710.656J

Therefore, the quantity of heat produced by the reaction is +26710.656J.

Note: Even though heat is given out by the system and is normally written as a negative value to indicate that heat is lost, the answer is written as a positive decimal number according to instruction.