Chemical Formulae And Equations
Overview
Chemistry has its own shorthand. Instead of writing 'two hydrogen atoms bond with one oxygen atom to make water', chemists write H₂O. Instead of describing a reaction in a paragraph, they write a balanced equation that shows exactly what reacts and what is produced.
In this lesson you will learn how to write word equations and balanced symbol equations with state symbols, and how to calculate relative formula masses from relative atomic masses. These skills underpin almost every calculation you will meet in chemistry.
Objectives
- Write word equations and balanced chemical equations (including state symbols) for reactions studied in this specification and for unfamiliar reactions where suitable information is provided
- Calculate relative formula masses (including relative molecular masses) (Mr) from relative atomic masses (Ar)
Lesson Note
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Lesson Evaluation
Congratulations on completing the lesson on Chemical Formulae And Equations. Now that youve explored the key concepts and ideas, its time to put your knowledge to the test. This section offers a variety of practice questions designed to reinforce your understanding and help you gauge your grasp of the material.
You will encounter a mix of question types, including multiple-choice questions, short answer questions, and essay questions. Each question is thoughtfully crafted to assess different aspects of your knowledge and critical thinking skills.
Use this evaluation section as an opportunity to reinforce your understanding of the topic and to identify any areas where you may need additional study. Don't be discouraged by any challenges you encounter; instead, view them as opportunities for growth and improvement.
- What does the state symbol (aq) represent? A) Solid B) Liquid C) Gas D) Dissolved in water Answer: D
- When balancing a chemical equation, you should adjust: A) The subscripts in formulae B) The coefficients in front of formulae C) The symbols of the elements D) The state symbols Answer: B
- What is the relative formula mass of CO2? (Ar: C = 12, O = 16) A) 28 B) 32 C) 44 D) 48 Answer: C
- In the equation 2H2 + O2 -> 2H2O, how many oxygen atoms are on the left side? A) 1 B) 2 C) 3 D) 4 Answer: B
- Which of these is a correctly balanced equation? A) H2 + O2 -> H2O B) 2H2 + O2 -> 2H2O C) H2 + O2 -> 2H2O D) 2H2 + 2O2 -> 2H2O Answer: B
Available on the Green Bridge App
Download the Green Bridge CBT app on your phone or computer to access full lesson notes, practice questions, and more.
Available on the Green Bridge App
Download the Green Bridge CBT app on your phone or computer to access full lesson notes, practice questions, and more.
Practice Mock Questions
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