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Grade 11 Challenge: Chemistry in the Real World Worksheet with Answers
Grade 11 (US) · Year 12 (UK) · Class 11 (India) · Science
Unit 6: Going FurtherReal-World ChallengesChallenge
Stoichiometry that matters: airbags, a tank of petrol's CO₂, tyre pressure in winter, medicine half-lives and dilutions. This free high school worksheet has 12 questions and a full answer key. Print it or save it as a PDF — every answer is checked by code, not guessed.
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Practice Sheetaethelsystems.comChallenge: Chemistry in the Real World
Grade 11 · Science
Name
Class
Date
Learning goal: Real-World Challenges
Directions: Read each question carefully and write your answer on the line.
A patient takes 500 mg of a drug with a half-life of 4 hours. How many mg remain after 24 hours, to 1 decimal place?
Answer: 7.8
- 1
Car airbags inflate when sodium azide decomposes: 2 NaN3 → 2 Na + 3 N2. How many grams of sodium azide (65.01 g/mol) are needed to make 70 L of nitrogen at STP (22.4 L/mol)? Give 1 decimal place.
- 2
A patient takes 200 mg of a drug with a half-life of 4 hours. How many mg remain after 24 hours, to 1 decimal place?
- 3
Car airbags inflate when sodium azide decomposes: 2 NaN3 → 2 Na + 3 N2. How many grams of sodium azide (65.01 g/mol) are needed to make 40 L of nitrogen at STP (22.4 L/mol)? Give 1 decimal place.
- 4
A patient takes 500 mg of a drug with a half-life of 8 hours. How many mg remain after 12 hours, to 1 decimal place?
- 5
Petrol is mostly octane, C₈H₁₈ (114.23 g/mol), with density 0.70 kg/L. It burns as 2 C₈H₁₈ + 25 O₂ → 16 CO₂ + 18 H₂O. How many kg of CO₂ (44.01 g/mol) does a 50 L tank produce? Give 1 decimal place.
- 6
Heating 25 g of limestone, CaCO₃ (100.09 g/mol), gives quicklime, CaO (56.08 g/mol), and CO₂. A student collects 11.2 g of CaO. What is the percent yield, to 1 decimal place?
- 7
A tyre's absolute air pressure is 320 kPa at 20 °C. Assuming its volume stays the same, what is the pressure at -15 °C, to the nearest kPa?
- 8
2 g of hydrogen (2.016 g/mol) reacts with 80 g of oxygen (32.00 g/mol): 2 H₂ + O₂ → 2 H₂O. What is the greatest mass of water (18.02 g/mol) that can form, in grams to 1 decimal place?
- 9
A strong acid has pH 3. To make its pH 5, how many mL of water must you add to 10 mL of it?
- 10
A patient takes 200 mg of a drug with a half-life of 8 hours. How many mg remain after 24 hours, to 1 decimal place?
- 11
A strong acid has pH 2. To make its pH 3, how many mL of water must you add to 25 mL of it?
- 12
8 g of hydrogen (2.016 g/mol) reacts with 32 g of oxygen (32.00 g/mol): 2 H₂ + O₂ → 2 H₂O. What is the greatest mass of water (18.02 g/mol) that can form, in grams to 1 decimal place?
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Free printable worksheets with answer keys · aethelsystems.com/worksheets/science/11/challenge_chemistry_world
Answer key — Challenge: Chemistry in the Real World (Grade 11)
- 1.135.4
- 2.3.1
- 3.77.4
- 4.176.8
- 5.107.9
- 6.80.0%
- 7.282
- 8.17.9
- 9.990
- 10.25.0
- 11.225
- 12.36.0
Answer key (click to show)
- 1.135.4
- 2.3.1
- 3.77.4
- 4.176.8
- 5.107.9
- 6.80.0%
- 7.282
- 8.17.9
- 9.990
- 10.25.0
- 11.225
- 12.36.0
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