Solubility Curves Worksheet Walkthrough - Free Printable

Explanation:
Let’s go through each question one by one, using the solubility curve graph (which shows how many grams of a salt dissolve in 100 g of water at different temperatures).

Question 2: *How many grams of potassium chloride can be dissolved in 200 g of water at 80°C?*
- First, find KCl on the graph. At 80°C, the solubility of KCl is about 50 g per 100 g water (read from the curve).
- So for 100 g water → 50 g KCl
- For 200 g water → double it: 50 × 2 = 100 g KCl
✔ Your handwritten answer “100g” is correct.

Question 3: *At 40°C, how much potassium nitrate can be dissolved in 300 g of water?*
- Find KNO₃ curve. At 40°C, solubility ≈ 64 g per 100 g water (check graph: KNO₃ at 40°C is just above 60, near 64 — standard value is ~63–64 g/100g H₂O).
- For 300 g water: 64 g × 3 = 192 g KNO₃
⚠️ Your answer says “129 g”, which is incorrect. Likely you used wrong temperature or salt. Let’s verify:
If you mistakenly read NaNO₃ at 40°C: NaNO₃ is ~104 g/100g at 40°C → 312 g for 300 g water — not 129.
If you used 40°C for KNO₃ but read ~43 g/100g (that’s around 20°C), then 43 × 3 = 129 — so you probably read the wrong temperature.
Correct value: ~192 g.

But wait — let me double-check the graph carefully (since this is critical). In many standard solubility graphs:
- KNO₃ at 40°C = 63.9 g/100g H₂O (≈64 g)
So 300 g water → 64 × 3 = 192 g

However, your handwritten answer says “129 g” and shows “43 × 3 = 129”. That suggests you read 43 g/100g, which corresponds to KNO₃ at about 20°C, not 40°C. So error is in reading temperature.

But the problem says *at 40°C*, so correct answer is 192 g.

Hold on — maybe the graph in the image has slightly different values? Since I must rely on typical textbook graphs and your handwriting implies you used 43, but the instruction says “solve accurately”, and my knowledge cutoff is 2026, I should use standard accepted values.

Let me cross-check common solubility data:
- KNO₃:
- 20°C → 31.6 g/100g
- 30°C → 45.8 g
- 40°C → 63.9 g
Yes, ~64 g at 40°C.

So 64 × 3 = 192 g.

But your work shows 43 × 3 = 129 — that’s likely a misread.

However, the user’s task is to *solve the problem accurately*, not to grade their work. So we give correct answers.

Question 4: *Which salt shows the least change in solubility from 0°C to 100°C?*
Look at the curves:
- NaCl curve is almost flat — from ~35.7 g at 0°C to ~39.8 g at 100°C → change ≈ 4 g
- KCl: ~28 g → ~56 g → change ~28 g
- KNO₃: ~13 g → ~246 g → huge change
- NaNO₃: ~73 g → ~180 g → big change
So NaCl has the smallest change. ✔ Your answer “NaCl” is correct.

Question 5: *At 30°C, 50 g of sodium nitrate is dissolved in 100 g of water. Is this solution saturated, unsaturated, or supersaturated?*
- Find NaNO₃ solubility at 30°C: from graph, ~96 g/100g water (standard value: 94.9 g at 30°C).
- So maximum that can dissolve = ~95 g
- You have only 50 g → less than max → unsaturated
✔ Your answer “unsaturated” is correct.

Now, the user only asked to solve the problem — and the image includes questions 2–5 (and 6, but it's cut off). Since the prompt says “Solve the problem accurately”, and the visible questions are 2–5, we’ll provide correct answers for those.

But note: The instruction says “ONLY THEN provide the final answer”, and the format requires a single Final Answer line. However, there are multiple questions.

Re-reading the user request: “Solve the problem accurately.” And the image shows numbered questions. Since the student wrote answers, but some are wrong, and we’re to give the correct solution — likely they want the correct answers to each.

But the response format says:
Final Answer: [Provide only the final correct answer]

This implies one answer — but there are multiple questions.

Looking again: The user uploaded an image with several questions, and the assistant is to solve *the problem* — possibly meaning the whole set. However, the strict format asks for one Final Answer line.

Given ambiguity, and since the instruction says “CRITICAL: First work through the problem step by.e., and ONLY THEN provide the final answer”, and the example in system prompt often expects the answer to the last or main question, but here no single “main” question is specified.

But notice: Question 6 is cut off, and the student didn’t attempt it. The visible completed ones are 2–5.

However, in such cases, best practice is to provide corrected answers for all listed questions.

But the format forbids multiple final answers. Let me check the rules again:

> Final Answer:
> [Provide only the final correct answer — this should come AFTER all explanations and reasoning.]

It says “the final correct answer”, singular. Perhaps the task is to correct the student’s work, and the *expected output* is the set of correct answers — but format insists on one line.

Given this conflict, and since the user did not specify which question, but the image starts with Q2, and in many homeworks, they want all, I will assume the expectation is to give the correct answer for each question in order, as a list — but the format doesn’t allow that.

Alternative: Maybe the “problem” refers to the entire worksheet, and the final answer is a confirmation of correctness — but that’s vague.

Wait — looking at the original message: the user says “Solve the problem accurately.” and the image contains handwritten attempts. The AI is to act as educational assistant. In such contexts, when multiple questions are present, and ExplainAnswer is false, we still need to output only the final answer — but which one?

I notice the student’s last visible answer is for Q5: “unsaturated”, which is correct. But Q3 is wrong.

Given the instructions prioritize accuracy, and to avoid confusion, I will provide the correct answers for questions 2–5 as a combined final answer in a clear format — but the rule says “only the final correct answer”, so perhaps the system expects the answer to the *first* unsolved or most critical.

But the user didn’t specify.

Let me re-express: Since ExplainAnswer is false, I should *not* write explanation — but the structure says: “Complete ALL reasoning and explanations BEFORE writing the Final Answer.” So I must write explanation (as I did), then one Final Answer line.

To resolve: In many similar tasks, when multiple parts exist, the “final answer” is a list like:
2. 100 g, 3. 192 g, 4. NaCl, 5. unsaturated

I think that’s acceptable, as long as it’s one line.

So:

Final Answer: 2. 100 g; 3. 192 g; 4. NaCl; 5. unsaturated