Packet 12: Bonus 10
The common-ion effect refers to the decrease in this property of the precipitate when an ion shared by a weak electrolyte is added. For 10 points each:
[10e] Name this property that can be quantified with a Ksp (“K-S-P”), its namesake “product constant,” or as the amount of one substance dissolved in another at maximum saturation.
ANSWER: solubility [accept word forms like soluble; accept solubility product constant]
[10m] The decreased solubility resulting from the common-ion effect can be explained using this principle. This principle predicts that the forward reaction becomes more favorable with higher reactant concentration.
ANSWER: Le Chatelier’s (“luh sha-tell-YAY’s”) principle [or Braun–Le Chatelier principle or Le Chatelier–Braun principle; prompt on equilibrium law]
[10h] This quantity for ionic solutions is important for describing deviations from ideality since the Debye (“duh-BYE”) length is inversely proportional to its square root. This quantity equals [read slowly] “one-half times the sum over all ions of concentration times charge squared.”
ANSWER: ionic strength [or molar ionic strength]
<Editors, Chemistry> | Packet L
| Editions | Heard | PPB | Easy % | Medium % | Hard % |
|---|---|---|---|---|---|
| 2 | 107 | 13.74 | 74% | 62% | 2% |
Conversion
| Team | Opponent | Part 1 | Part 2 | Part 3 | Total | Parts |
|---|---|---|---|---|---|---|
| Durham A | Durham C | 10 | 10 | 0 | 20 | EM |
| Durham B | York | 10 | 10 | 0 | 20 | EM |
| Edinburgh A | Edinburgh D | 0 | 0 | 0 | 0 | |
| Edinburgh B | Edinburgh C | 0 | 10 | 0 | 10 | M |
| Sheffield A | Sheffield B | 0 | 10 | 0 | 10 | M |
Summary
| Tournament | Edition | Exact Match? | Heard | PPB | Easy % | Medium % | Hard % |
|---|---|---|---|---|---|---|---|
| UK (North) | UK | Y | 5 | 12.00 | 40% | 80% | 0% |
| UK (South) | UK | Y | 8 | 12.50 | 63% | 63% | 0% |
| Southern California | US | Y | 7 | 20.00 | 86% | 100% | 14% |
| Eastern Canada (2) | US | Y | 10 | 30.00 | 150% | 140% | 10% |
| Great Lakes | US | Y | 12 | 15.00 | 75% | 75% | 0% |
| Lower Mid-Atlantic | US | Y | 6 | 5.00 | 17% | 33% | 0% |
| Upper Mid-Atlantic | US | Y | 12 | 10.83 | 75% | 33% | 0% |
| Midwest | US | Y | 9 | 12.22 | 67% | 56% | 0% |
| Northeast | US | Y | 12 | 10.83 | 67% | 42% | 0% |
| Pacific | US | Y | 9 | 10.00 | 56% | 44% | 0% |
| Southeast | US | Y | 12 | 11.67 | 67% | 50% | 0% |
| Upstate NY | US | Y | 5 | 12.00 | 100% | 20% | 0% |