chapters 4, and 5. solution: electrolyte: nonelectrolyte:
TRANSCRIPT
The diagram below represents an aqueous solution of one of the following compounds: MgCl2, KCl, or K2SO4. Which solution does the drawing best represent?
Predict the identity of the precipitate that forms when solutions of BaCl2 and K2SO4 are mixed. Write the balanced chemical equation for the reaction.
Write a balanced molecular equation for the reaction between aqueous solutions of acetic acid and barium hydroxide. Write the net ionic equation for this reaction.
Calculate the molarity of a solution made by dissolving 23.4 g of sodium sulfate in enough water to form 125 mL of solution.
What are the molar concentrations of each of the ions present in a 0.025 M aqueous solution of calcium nitrate?
Enthalpy
Heat transfer from system to surroundings
Heat transfer from surroundings to system
Enthalpy
The enthalpy of reaction for the combustion of C(s) to CO2(g) is -393.5 kJ/mol, and the enthalpy for the combustion of CO to CO2 is -283.0 kJ/mol:
C(s) + O2(g) CO2(g) ΔH = -393.5 kJ
CO(g) + ½ O2(g) CO2(g) ΔH = -283.0 kJ
Use this information to calculate the enthalpy for the combustion of C(s) to CO(g)
Which of the following is the correct net ionic equation for the reaction of sodium hydroxide and nitric acid?
(A) H+ + OH- H2O
(B) Na+ + NO3- NaNO3
(C) NaOH + HNO3 NaNO3 + H2O
(D) Na+ + OH- + H+ + NO3- NaNO3 + H2O
(E) Na+ + OH- + 2 H+ NaOH + H2
Example Questions
What volume of distilled water should be added to 20 mL of 5 M HCl to prepare a 0.8 M solution?
(A) 100 mL
(B) 105 mL
(C) 125 mL
(D) 200 mL
Compound Δhof (kJ/mol)
CO2(g) -393.5
CaO(s) -635.5
CaCO3(s) -1,207.1
The decomposition of CaCO3(s) is shown in the equation to the right. Using the data in the table, which of the following values is closest to the ΔHrxn of the decomposition of CaCO3(s)?
(A) -2,240 kJ/mol
(B) -180 kJ/mol
(C) 180 kJ/mol
(D) 1,207 kJ/mol
(E) 2,240 kJ/mol
A 0.2 mol sample of MgCl2(s) and a 0.1 mol sample of KCl(s) are dissolved in 500 mL of water. What is the concentration of Cl- in the resulting solution?
(A) 0.15 M
(B) 0.30 M
(C) 0.60 M
(D) 1.0 M
2 CH6N2 + 5 O2 2 N2 + 2 CO2 + 6 H2O(g)
The combustion of methylhydrazine, is represented above. The ΔH of this reaction is -1,303 kJ/mol. What would bout the ΔH per mole CH6N2 if the reaction produced H2O(l) instead of H2O(g)? (The ΔH for the condensation of H2O(g) to H2O(l) is -44 jk/mol)
(A) -1,171 kJ
(B) -1,259 kJ
(C) -1,347 kJ
(D) -1,435 kJ