1. Heat Stoichiometry Review Quiz
Heat = mass x ΔT x specific heat
For each reaction write the balanced chemical equation including the energy term, and indicate whether the reaction is endothermic or exothermic.   
1 (A) When 9.36 g of sodium carbonate reacts with an excess of hydrochloric acid, 2.22 KJ of heat are released.
1 (B) When 2.00 g of ammonium nitrate is dissolved in ml of water, the temperature of the solution decreases from 25.58oC to 22.34oC.

2. Heat Stoichiometry Review Quiz
Heat = mass x ΔT x specific heat
For each reaction write the balanced chemical equation including the energy term, and indicate whether the reaction is endothermic or exothermic.   
2(A) When 2.50 g of magnesium chloride is dissolved in ml of water, the temperature of the solution increases from 21.00oC to 24.70oC.
2(B) 34.4 KJ are needed for 82.3 g of mercury (II) oxide to decompose into its component elements.

3. When 9.36 g of sodium carbonate reacts with an excess of hydrochloric acid 2.45 KJ of heat are released.
1mole Na2CO3 = 106 g = 9.36 g x KJ x KJ KJ
x = KJ Exothermic
Na2CO3 + 2 HCl → H2O + CO2 + 2NaCl KJ

4. 0.677 KJ = 27.1 KJ / mole Endothermic 0.025 mole
When 2.00 g of ammonium nitrate is dissolved in ml of water, the temperature of the solution decreases from 25.58oC to 22.34oC.
Heat = g x 3.24 oC x 4.18 J/goC = 677 J
2.00 g NH4NO3 x 1 mole = mole
80.0g
0.677 KJ = KJ / mole Endothermic
0.025 mole
27.1 KJ + NH4NO3 → (NH4) (NO3)1-

5. Exothermic MgCl2 → Mg2+ + 2 Cl1- + 14.8 KJ
When 2.50 g of magnesium chloride is dissolved in ml of water, the temperature of the solution increases from 21.00oC to 24.70oC.
Heat = g x 3.70 oC x 4.18 J/g oC = 387 J
2.50g MgCl2 x 1mole = mole
95.3g
0.387 KJ
mole = KJ / mole
Exothermic MgCl2 → Mg Cl KJ

6. 34.4 KJ are needed for 82.3 g of mercury (II) oxide to decompose into its component elements.
x KJ = x KJ = kJ x = KJ
1 mole g HgO g Endothermic
181 KJ + 2HgO → 2 Hg + O2