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Barium hydroxide reacts with dilute hydrochloric acid to form barium chloride and water - Edexcel - GCSE Chemistry Combined Science - Question 5 - 2022 - Paper 1
Question 5
Barium hydroxide reacts with dilute hydrochloric acid to form barium chloride and water. (a) The equation for the reaction is Ba(OH)₂(s) + 2HCl(aq) → BaCl₂(aq) + 2... show full transcript
Worked Solution & Example Answer:Barium hydroxide reacts with dilute hydrochloric acid to form barium chloride and water - Edexcel - GCSE Chemistry Combined Science - Question 5 - 2022 - Paper 1
Step 1
Which row of the table shows the correct state of each of the substances in the equation for the reaction?
Answer
The correct answer is A: barium hydroxide is a solid, hydrochloric acid is aqueous, barium chloride is aqueous, and water is a liquid. This reflects the states of the reactants and products in the balanced chemical equation.
Step 2
A student wanted to investigate how the pH of the mixture changes as barium hydroxide is added to dilute hydrochloric acid.
Answer
The method outlined is effective for determining pH changes.
- Step 1: Measure out 50.0 cm³ of dilute hydrochloric acid into a beaker using a measuring cylinder.
- Step 2: Use a glass rod to place a drop of the acid onto a piece of universal indicator paper and record the colour.
- Step 3: Add 0.2 g of barium hydroxide to the acid in the beaker and stir.
- Step 4: Use the glass rod to place a drop of the mixture onto a new piece of universal indicator paper and record the pH again.
- Step 5: Repeat steps 3–4 until there is no further change in the pH.