Using Moles to Balance Equations Simplified Revision Notes for GCSE AQA Chemistry

Revision notes with simplified explanations to understand Using Moles to Balance Equations quickly and effectively.

Learn about Calculating Mass of Substances for your GCSE Chemistry Exam. This Revision Note includes a summary of Calculating Mass of Substances for easy recall in your Chemistry exam

326+ students studying

3.2.3 Using Moles to Balance Equations

Balancing Equations with Moles

infoNote

You can also use moles to help balance chemical equations. This involves converting the mass of each substance in the reaction to moles, finding the simplest ratio of moles, and then using that ratio to balance the equation.

infoNote

Worked Example:

Imagine you are making ammonia (NH₃) by reacting nitrogen (N₂) with hydrogen (H₂). You start with 5.6 g of nitrogen and 1.2 g of hydrogen, and you end up with 6.8 g of ammonia. Here's how you would write the balanced equation:

Calculate the moles:

Moles of nitrogen:

Moles of N_2 = \frac{5.6 g}{28 (Mr of N_2) = 0.2 moles}

Moles of hydrogen:

Moles of H_2 = \frac{1.2 g}{2 (Mr of H_2) = 0.6 moles}

Moles of ammonia:

Moles of NH_3 = \frac{6.8 g}{17 (Mr of NH_3) = 0.4 moles}

Simplify the ratio by dividing all the mole amounts by the smallest one (0.2):

Nitrogen:

\frac{0.2}{0.2}=1

Hydrogen:

\frac{0.6}{0.2}=3

Ammonia:

\frac{0.4}{0.2}=2

Write the balanced equation:

N_2+3H_2→2NH_3

500K+ Students Use These Powerful Tools to Master Using Moles to Balance Equations For their GCSE Exams.

Enhance your understanding with flashcards, quizzes, and exams—designed to help you grasp key concepts, reinforce learning, and master any topic with confidence!

60 flashcards

Flashcards on Using Moles to Balance Equations

Revise key concepts with interactive flashcards.

Try Chemistry Flashcards

6 quizzes

Quizzes on Using Moles to Balance Equations

Test your knowledge with fun and engaging quizzes.

Try Chemistry Quizzes

29 questions

Exam questions on Using Moles to Balance Equations

Boost your confidence with real exam questions.

Try Chemistry Questions