AP Chemistry Unit 6 Review

• Exothermic, -92 kJ/mol

• Endothermic, +92 kJ/mol

• Exothermic, +92 kJ/mol

• Endothermic, -92 kJ/mol

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1

Given the following bond energies, find the missing value for A-A bond energy: A-A + B=B → 2 A-B-A, with an enthalpy of -25 kJ.

• 50 kJ/mol

• 60 kJ/mol

• 70 kJ/mol

• 80 kJ/mol

Tags

NGSS.HS-PS1-4

Calculate the standard enthalpy change when 0.452 moles of N2H4 is formed at 1 atm and 298 K, given the reaction: 2H2(g) + N2(g) → N2H4(g) with ΔH° = +50.63 kJ/mol.

• 22.89 kJ

• 50.63 kJ

• 11.45 kJ

• 100.26 kJ

Tags

NGSS.HS-PS1-4

If 2.38 moles of CH4 reacts with 8.21 moles of O2, how much heat would be evolved given the reaction: CH4(g) + 2O2(g) → CO2(g) + 2H2O(g) with ΔH = -802 kJ?

• -1908.76 kJ

• -802 kJ

• -1604.76 kJ

• -3209.52 kJ

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-4

How many moles of EF would be produced if the reaction AB(g) + 2 CD(g) → 3 EF(g) with ΔH = -9.52 kJ gave off 750 J?

• 0.236 moles

• 0.079 moles

• 0.315 moles

• 0.157 moles

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1

A student mixes 0.100 L of 1.00 M HA with 0.200 L of 1.00 M MOH. If the temperature of the solutions changed from 22.3 °C to 29.1 °C, calculate the heat evolved in this reaction. Assume that the specific heat of the solution is 4.184 J/g°C and the density of the solutions is 1.00 g/mL.

• 1.90 kJ

• 2.00 kJ

• 2.10 kJ

• 2.20 kJ

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-4

The formation of magnesium oxide, MgO, is shown by the reaction: Mg(s) + 1/2 O2(g) → MgO(s) + 601.7 kJ. Is this an endothermic or exothermic reaction?

• Endothermic

• Exothermic

• Neither

• Both

Tags

NGSS.HS-PS1-4

2.00 grams of NaOH is added to 100.0 mL of water at 22.0 °C. After dissolving, the temperature of the solution is found to be 27.3°C. What is the experimental value for the molar enthalpy of dissolution for NaOH?

• 44.5 kJ/mol

• 45.5 kJ/mol

• 46.5 kJ/mol

• 47.5 kJ/mol

When solid phosphorus, P, reacts with gaseous chlorine, Cl2, it forms liquid phosphorus trichloride, PCl3. When 4.62 grams of phosphorus reacts with excess chlorine at constant pressure, 47.8 kJ of heat is released. What is the thermochemical equation for this reaction?

• P(s) + 3/2 Cl2(g) → PCl3(l) + 47.8 kJ

• P(s) + Cl2(g) → PCl3(l) + 47.8 kJ

• P(s) + 3 Cl2(g) → PCl3(l) + 47.8 kJ

• P(s) + 1/2 Cl2(g) → PCl3(l) + 47.8 kJ

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-4

Calculate the amount of energy needed to boil 91.2 grams of carbon tetrachloride, CCl4, at its boiling point, 350.0 K. ΔHvap = 26.7 kJ/mole

• 15.38 kJ

• 30.12 kJ

• 26.7 kJ

• 91.2 kJ

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-4