1) Write the balanced reaction between magnesium and oxygen to create 1 mole of magnesium oxide. Show the calculation of the theoretical enthalpy of reaction using the heats of formation values from your textbook. Show all your work including all phase labels. Report your answer in kJ/1 mole of magnesium.

Hydrazine is an inorganic compound with the chemical formula N2H4. The reaction of hydrazine with chlorine trifluoride has been used in experimental rocket motors in the reaction below: 3N2H4 (1) + 4CIF3 (g) → 3N2 (g) + 12HF (g) + 2C12 (g) Calculate enthalpy change for the reaction given the following: (1) 2CIF3 + 2NH3 → N2 + 6HF + Cl2 (2) N2H4 + O2 → N2 + 2H2O (3) 4NH3 + 302→ 2N2 + 6H20 AH°= -1196 kJ AH°= - 622 kJ AH° = - 1530 kJ

Consider the following hypothetical reaction XY + Z → XZ + Y + 20 kJ What bond is being broken?  Breaking this bond requires energy/releases energy (circle one). What bond is being formed?  Forming this bond requires energy/releases energy (circle one). What is the sign for the change in enthalpy of this reaction? Based on the enthalpy, what relationship can you draw between the energy of the bonds breaking and the energy of bonds forming in this reaction? The energy needed to break an XY bond is 70 kJ. What is the energy produced when an XZ bond forms?

Don't give handwritten answers  Which of the following is the formation reaction for N2O (g)? Group of answer choices A.) 1/2 N2(g) + 2 O2(g) → NO2(g) B.) 1/2 N2(g) + O2(g) → NO2(g) C.) N(g) + O2(g) → NO2(g) D.) 2 N2(g) + O2(g) → 2 NO2(g) E.) N(g) + 2 O(g) → NO2(g)

a. Calculate the enthalpy of reaction for: 2 CO(g) + O2(g) → 2 CO2(g) b. If 18.5 grams of carbon dioxide are produced, what is the change in energy in kJ?

If a reaction causes 25.0 g of water to decrease temperature by 14.24 oC at constant pressure, what is the change in enthalpy for the reaction in kJ ? (The specific heat capacity of water is 4.184 J/g oC). Assume no heat transferred to surroundings.

7. Calculate the enthalpy of the following reaction. FL + HBr + H₂O 5 so OH Br + HI + HF

Use average bond enthalpy (D) values available under the Thermochemistry heading on ACORN to calculate ΔrH for the following reaction: 2NH3 + 3Cl2 → N2 + 6HCl Express your answer to 3 significant figures.

3. Hydrazine, N2H4, is a colorless liquid used as a rocket fuel. What is the enthalpy change for the process in which hydrazine is formed from its elements? N2(g) + 2H2(g) → N2H4(l) Use the following reactions, enthalpy changes, and Hess’s Law N2H4(l) + O2(g) → N2(g) + 2H2O(l); ΔrH° = −622.2 kJ H2(g) + ½O2(g) → H2O(l); ΔrH° = −285.8 kJ

The integrated circuits in your cell phone and computer are made from the semiconductor silicon. The silicon is obtained from a really inexpensive starting material, sand, which is primarily SiO2. One step in the purification of silicon is to separate it from solid impurities by forming the gas silicon tetrachloride. Given the following reactions, which are performed one at a time, what is the overall enthalpy change in converting 1.00 mol of silicon dioxide into pure silicon? Reaction AH (kJ) SIO2(s) + 2C(s) → Si(impure s) + 2C0(g) Si(impure s) + 2CI2(g) SICI4(g) + 2Mg(s) → 2M9CI2(s) + Si(s) +690 SICI4(g) -657 -625 Select one: a. +592 kJ b.-625 kJ C. +1,972 kJ d. -1,972 kJ e. -592 kJ