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Amount of Substance

Balanced Equations and Reaction Calculations

  • 3 things to know
  • Papers 1, 2 and 3

Overview

Balancing equations and using the ratios in them to work out reacting masses.

What you need to know

Answer each one before you reveal it.

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Key term

What formula relates the concentration, volume, and number of moles of a solution?

Key term

What must be conserved in a balanced chemical equation?

Key term

In terms of atoms, what does balancing a chemical equation ensure?

Questions from this subtopic

Each one with the model answer underneath.

  1. 1

    What must be conserved in a balanced chemical equation?

    Model answer

    Mass and the number of atoms of each element on both sides of the equation

  2. 2

    In terms of atoms, what does balancing a chemical equation ensure?

    Model answer

    The same number of atoms of each element appears on both sides

  3. 3

    What is the relationship between the coefficients in a balanced equation and the molar ratios of reactants and products?

    Model answer

    The coefficients represent the ratio of moles in which substances react and are produced

  4. 4

    How can the mass of a product be calculated from a balanced equation and the mass of a reactant?

    Model answer

    Convert mass of reactant to moles, use the molar ratio to find moles of product, then convert moles of product to mass

  5. 5

    What is the first step when calculating the mass of product formed from a given mass of reactant?

    Model answer

    Convert the mass of reactant to moles using moles = mass ÷ molar mass

  6. 6

    After finding the moles of reactant, how do you determine the moles of product formed?

    Model answer

    Use the molar ratio from the balanced equation to convert moles of reactant to moles of product

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Atomic Structure
Amount of Substance
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AOxidation is the loss of electrons.
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The sum of all mole fractions equals 1.
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