Chemistry Homework Solver Examples: 11 Worked Problems With Full Steps

TL;DR

Below are 11 chemistry homework problems solved in full, with every number worked out, so you can compare an AI chemistry solver's output against a correct method. Each example ends with the check a teacher would apply. After the examples you'll find a prompt template and a five-point verification routine.

Want to try your own problem? Paste it into TextSpell's Chemistry Homework Solver or the AI Chemistry Solver, then compare its steps with the patterns below.

The Prompt That Gets Step-by-Step Answers

Most bad chemistry answers come from incomplete input: a cropped photo, a missing unit, or no reaction conditions. Use this prompt with any solver:

Solve this chemistry problem step by step.
Problem: [paste the complete question, including units and conditions]
Show:
1) the balanced equation, if needed
2) the formula you chose and why it applies
3) every unit conversion
4) intermediate values (unrounded)
5) the final answer with units and correct significant figures
6) a one-line reasonableness check
State any assumptions.

If you don't know what type of problem it is, ask first: "Identify the chemistry topic, list the given quantities and the unknown. Don't calculate yet." Fixing the setup before the arithmetic saves the most time.

Worked Chemistry Homework Solver Examples

Atomic masses used: H 1.008, C 12.01, O 16.00, Mg 24.31, Al 26.98, Ca 40.08 g/mol. If your course uses a different periodic table, your last digit may differ slightly.

1. Balancing an equation

Question: Balance Al + O2 → Al2O3.

1. Oxygen appears as O₂ on the left and O₃ on the right. The least common multiple of 2 and 3 is 6, so put 3 in front of O₂ and 2 in front of Al₂O₃.
2. That gives 4 Al on the right, so put 4 in front of Al.

4Al + 3O2 → 2Al2O3

Check: Al: 4 = 4. O: 6 = 6. The coefficients 4, 3, 2 share no common factor, so this is the simplest ratio.

2. Molar mass

Question: Find the molar mass of Ca(OH)2.

Check: The subscript 2 outside the parentheses applies to both O and H. Forgetting that gives 57.09 g/mol, which is the most common mistake on this problem.

3. Limiting reagent

Question: 4.0 mol H₂ reacts with 1.5 mol O₂. Which is limiting, and how much water forms?

1. Balanced equation: 2H2 + O2 → 2H2O.
2. 4.0 mol H₂ would need 4.0 ÷ 2 = 2.0 mol O₂. Only 1.5 mol is available, so O₂ is limiting.
3. Water formed: 1.5 mol O₂ × (2 mol H₂O / 1 mol O₂) = 3.0 mol H₂O (54 g).
4. H₂ used: 1.5 × 2 = 3.0 mol, so 1.0 mol H₂ is left over.

Check: Compare by mole ratio, not by which number is smaller. Here the smaller number (1.5 mol O₂) happens to be limiting, but that is not always true.

4. Theoretical yield from grams

Question: 5.0 g Mg reacts with excess hydrochloric acid. What mass of H₂ forms?

1. Balanced equation: Mg + 2HCl → MgCl2 + H2.
2. Moles of Mg: 5.0 g ÷ 24.31 g/mol = 0.2057 mol.
3. Mole ratio Mg : H₂ = 1 : 1, so 0.2057 mol H₂.
4. Mass of H₂: 0.2057 mol × 2.016 g/mol = 0.4147 g → 0.41 g H₂ (2 significant figures, from 5.0 g).

Check: The path is grams → moles → moles → grams. Any solver that applies the mole ratio directly to grams is wrong.

5. Percent yield

Question: Theoretical yield is 12.0 g and actual yield is 9.6 g. Find percent yield.

% yield = (actual ÷ theoretical) × 100 = (9.6 ÷ 12.0) × 100 = 80.%

Check: Percent yield above 100% means a wet or impure product, or a calculation error.

6. Molarity

Question: 0.50 mol of solute is dissolved to make 250 mL of solution. Find the molarity.

1. Convert volume: 250 mL = 0.250 L.
2. M = n ÷ V = 0.50 mol ÷ 0.250 L = 2.0 M.

Check: Using 250 instead of 0.250 gives 0.0020 M, which is off by a factor of 1,000.

7. Dilution

Question: 50.0 mL of 6.0 M HCl is diluted to 300. mL. What is the new concentration?

M1V1 = M2V2 → M2 = (6.0 M × 50.0 mL) ÷ 300. mL = 1.0 M

Check: The concentration must go down after adding solvent. The volume units cancel, so mL is fine here as long as both volumes use the same unit.

8. pH of a strong acid

Question: Find the pH of 1.0 × 10⁻³ M HCl.

1. HCl is a strong acid and dissociates completely, so [H⁺] = 1.0 × 10⁻³ M.
2. pH = −log(1.0 × 10⁻³) = 3.00.

Check: For pH, the number of decimal places equals the significant figures in the concentration. Two significant figures in 1.0 × 10⁻³ gives two decimal places: 3.00.

9. Ideal gas law

Question: 2.00 mol of gas occupies 10.0 L at 300. K. Find the pressure.

1. PV = nRT → P = nRT ÷ V, with R = 0.08206 L·atm/(mol·K).
2. P = (2.00 × 0.08206 × 300.) ÷ 10.0 = 4.92 atm.

Check: Temperature must be in kelvin. If the problem gives °C, add 273.15 first. R's units must match the units of V and P.

10. Organic: hydration of propene

Question: Predict the major product when propene reacts with water in acid.

1. H⁺ adds to the carbon with more hydrogens (C1). That forms the more stable secondary carbocation on C2 (Markovnikov's rule).
2. Water attacks C2 and loses a proton.
3. Major product: propan-2-ol (isopropyl alcohol).

Check: If a solver gives propan-1-ol, it skipped the carbocation-stability step. That anti-Markovnikov product needs hydroboration, not acid.

11. Organic: why tert-butyl bromide goes SN1

Question: Explain why tert-butyl bromide in water reacts by SN1, not SN2.

• Substrate: It forms a tertiary carbocation, which is stabilized by three alkyl groups.
• Sterics: Three methyl groups block the backside attack that SN2 needs.
• Solvent: Water is polar protic, so it stabilizes both the carbocation and the leaving bromide ion.
• Product: tert-butanol (2-methylpropan-2-ol).

Check: A good answer names all three factors. An answer that only says "tertiary means SN1" is incomplete.

How to Check Any AI Chemistry Answer

Run these five checks before you submit:

1. Transcription. If you uploaded a photo, compare every subscript, charge, decimal, and unit with the original. OCR often confuses CO with Co and l with 1.
2. Method. Ask why the chosen formula applies. Is the equation balanced before the mole ratio is used? Is the temperature in kelvin?
3. Units. Keep units in every line so they cancel visibly. An unexpected order of magnitude almost always means a missed conversion.
4. Significant figures. Keep extra digits in intermediate steps and round only the final answer.
5. Source. Compare with your notes or an open textbook such as OpenStax Chemistry 2e. If they disagree, find the exact step where they split.

Where Chemistry Solvers Need Extra Caution

AI explanations read fluently even when a coefficient is wrong, and accuracy drops as problems get longer. Be most careful with:

• Multi-stage stoichiometry
• Equilibrium problems that use the "small x" approximation
• Stereochemistry and reaction mechanisms
• Spectra or structures from low-quality images

Never use an AI answer as a lab procedure. Do not mix chemicals, change quantities, or handle hazardous materials based on generated text. Follow your instructor, the safety data sheet, and lab supervision.

A Study Loop That Actually Builds Skill

1. Attempt the problem and name the topic.
2. Ask the solver for the method, not just the answer.
3. Compare the setup with the matching worked example above.
4. Correct by asking about the exact step where your work diverged.
5. Practice by changing the numbers and solving again without the tool.

Which TextSpell Tool to Use

• Chemistry Homework Solver: assignment-style questions like the ones above
• AI Chemistry Solver: broader chemistry concepts and problem solving
• AI Homework Helper: multi-subject homework, including photo uploads
• AI Statistics Solver guide: if your lab report needs error analysis or averages

FAQ

What is a chemistry homework solver?

A chemistry homework solver explains chemistry questions step by step from typed text or a photo, including balancing, stoichiometry, concentration, and reaction logic. Use it to see the method, then verify the result.

Can an AI chemistry solver balance equations?

Yes, for most textbook equations. Still count every element on both sides and confirm the coefficients are in the smallest whole-number ratio.

Can AI solve chemistry homework accurately?

It is reliable on single-step problems when the prompt includes the full question, units, and conditions. Accuracy drops on multi-step and mechanism questions, so check the setup and units yourself.

Is it safe to follow lab instructions from an AI chemistry solver?

No. AI output is not a substitute for an approved lab procedure or supervision.