Consider the following system composed of five 1 M aqueous solutions; iron (II)
ID: 912653 • Letter: C
Question
Consider the following system composed of five 1 M aqueous solutions; iron (II) chloride, sodium sulfite, sulfuric acid, silver nitrate, and sodium hydroxide.
Yoou will mix the solutions in a pair wise fashion so that all possible reactions between the solutions are tested. Use the solubility rules to predict when the precipitation reaction will occur. For each combination that produces a precipitation reaction write a balanced molecular equation and a net ionic equation. Indicate all phases in your equations.
The combination of sodium sulfite and sulfuric acid does not produce a precipitate but does produce a foul smelling gas, sulfur dioxide, and molecular water. Write a balanced molecular equation and a net ionic equation for the reaction. Indicate all phases in your equations.
One combination of chemical above does not produce a precipitate or a gas but you notice the test tube warms up significantly upon mixing. This is due to the high heat of neutralization. Identify the pair that produces a neutralization reaction and write a balanced molecular equation and a net ionic equation. Indicate all phases in your equations.
Explanation / Answer
Combination of Na2SO3 + H2SO4
2Na+ + SO3-2 + 2H+ + SO4-2 -> Na2SO4 + SO2 + H2O
Na2SO3 + H2SO4 -> Na2SO4 + SO2 + H2O
Combination of NaOH + H2SO4
2Na+ + 2OH- + 2H+ + SO4-2 -> Na2SO4 +2H2O
2NaOH + H2SO4 -> Na2SO4 +2H2O + heat
Precipitates (following solubility rules, given that all hydroxides are insoluble and all sulfates are soluble except those of silver, mercury, lead, barium and calcium):
1) FeCl2 + 2NaOH -> Fe+2 + 2Cl- + Na+ + OH- -> 2NaCl + Fe(OH)2 (s)
2) Na2SO3 + 2AgNO3 -> 2Na+ + SO3-2 + Ag+ + NO3- -> 2NaNO3 + Ag2SO3 (s)
3) H2SO4 + 2AgNO3 -> 2H+ + SO4-2 + Ag+ + NO3- -> 2HNO3 + Ag2SO4 (s)