Determining an equation experimentally: sodium hydrogencarbonate (RAM 1 d.p.)
I can describe a safe experiment to calculate the stoichiometric values for the decomposition of sodium hydrogencarbonate.
Determining an equation experimentally: sodium hydrogencarbonate (RAM 1 d.p.)
I can describe a safe experiment to calculate the stoichiometric values for the decomposition of sodium hydrogencarbonate.
These resources will be removed by end of Summer Term 2025.
Lesson details
Key learning points
- Heating sodium hydrogencarbonate in a crucible leads to its decomposition.
- The risk involved with heating sodium hydrogencarbonate is low.
- The stoichiometry for a reaction can be calculated given experimental data.
- Because a gas is not a reactant in this reaction, the crucible lid remains closed throughout the heating process.
Keywords
Decomposition - A type of reaction where a reactant compound breaks down into two or more products.
Ratio - A ratio can be used to determine the size of one quantity in relation to another.
Stoichiometry - The molar ratio of the reactants and products in a chemical reaction.
Mole - 1 mole of a substance is 6.02 × 10²³ particles of it. The mass of a mole of a substance is its relative mass in grams.
Balanced symbol equation - A reaction using a symbol equation with coefficients to ensure there are equal numbers of atoms of each element on both sides of the equation.
Common misconception
Pupils may think that the mass of the crucible and contents will not change during the reaction because the lid is closed, believing that all gases produced remain inside.
Explain that even with the crucible lid on, gases like carbon dioxide & water vapour formed during decomposition can escape around the edges. This leads to a decrease in mass, which is crucial for calculating the stoichiometry based on the mass loss.
Equipment
Sodium hydrogencarbonate, spatula, weighing boat, balance, crucible + lid, clay triangle, tripod, Bunsen burner, heatproof mat, tongs.
Content guidance
- Risk assessment required - equipment
Supervision
Adult supervision required
Licence
This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
Lesson video
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Starter quiz
6 Questions
Exit quiz
6 Questions
A reaction where a reactant breaks down into two or more products.
No substances can enter or leave.
The mass of the reactants equals the mass of the products.
Ratio of particles that react/form in a chemical reaction.