Chapter 4 Homework Flashcards
Mixing which of the following two solutions would yield a precipitate?
CuSO4 + Na2S
Which of these acids is the weakest?
CH3COOH
After titrating each of the solutions in the amounts and concentrations indicated, which of these solutions has reached the neutralization point?
30 mL of 0.1 M HNO3 that is titrated with 30 mL of 0.10 M NaOH.
In a “potato clock,” a piece of zinc and a piece of copper are stuck into opposite ends of a potato. Wires from the zinc and the copper are connected to a digital clock. Enough electric current flows through this circuit to power the clock. Based on this evidence, what can you conclude about potatoes?
They contain electrolytes.
If 8.1 g of potassium sulfate K2SO4 (174.26 g / mol) are dissolved in water to form 175 mL of solution, what is the molarity of potassium ions (K+ ) in the solution?
0.53 M
If 5.0 g of sodium chloride NaCl (58.44 g / mol) and 8.2 g of sodium sulfate Na2SO4 (142.04 g / mol) are dissolved in water to make 200 mL of solution, what is the concentration of sodium ions (Na+ ) in the solution?
1.1 M
Which of the compounds shown below is likely to be the most soluble in water?
H11C5OH
Which of the following represents the net ionic equation of the combination of insoluble of aluminum hydroxide and a solution of hydrobromic acid?
Al(OH)3(s) + 3H+(aq) -> Al3+(aq) + 3H2O(l)
A solution of KOH is combined with a solution of FeCl3. What is the net ionic equation of the resulting precipitation reaction?
Fe3+(aq) + 3OH-(aq) -> Fe(OH)3 (s)
A solution of K2SO4 and KCl is added to a solution of Ba(NO3)2. Which of these compounds will precipitate out of this combined solution?
BaSO4 (s)
When two solutions are combined, a precipitation reaction occurs as shown below.
NH4+(aq) + AG+(aq) + I-(aq) + NO3-(aq) ->
NH4+(aq) + NO3-(aq) + AgI(s)
What were the original solutions if each contained a single dissolved ionic compound?
a solution of AgNO3 and a solution of NH4I
Suppose a researcher spills a small amount of strong acid in a laboratory. The addition of which of these substances would make the spill safer to clean up?
an excess of weak base
You have two neutral solutions. One contains the indicator methyl red, which turns red in strongly acidic aqueous solutions but is otherwise yellow. The other contains the indicator phenol red, which turns red in strongly basic aqueous solutions but is otherwise yellow. Which of these steps would allow you to tell which solution contained which indicator?
Add a strong acid to both solutions.
Suppose you titrate 25.2 mL of a 0.116 M solution of an unknown acid with 23.1 mL of a 0.253 M solution of KOH to reach the equivalence point. Which of these is the most likely formula for the unknown acid?
H2SO4
You need to titrate 38.2 mL of an acetic acid solution (CH3COOH). (Acetic acid is a monoprotic acid.) You begin your titration with a 0.12 M solution of KOH. After you have added 48.5 mL of the KOH solution, however, you realize that you forgot to add an indicator and have overshot the equivalence point. To neutralize the excess base, you use a second buret to add 10.2 mL of a 0.25 M solution of HCl, which brings the titrated solution back to the equivalence point. What is the molar concentration of the original acetic acid solution?
0.084 M