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Barium hydroxide reacts with dilute hydrochloric acid to form barium chloride and water - Edexcel - GCSE Chemistry - Question 2 - 2022 - Paper 1
Question 2
Barium hydroxide reacts with dilute hydrochloric acid to form barium chloride and water. (a) The equation for the reaction is $$\text{Ba(OH)}_2 (s) + 2\text{HCl}(a... show full transcript
Worked Solution & Example Answer:Barium hydroxide reacts with dilute hydrochloric acid to form barium chloride and water - Edexcel - GCSE Chemistry - Question 2 - 2022 - Paper 1
Step 1
Name a piece of equipment which could be used to measure out 50.0 cm³ of dilute hydrochloric acid more accurately than the measuring cylinder.
Answer
A volumetric flask could be used to measure out 50.0 cm³ of dilute hydrochloric acid more accurately than a measuring cylinder because it is designed for precise volume measurement.
Step 2
Describe how the pH of the mixture is determined when a drop of it is placed on the universal indicator paper.
Answer
When a drop of the mixture is placed on universal indicator paper, the paper changes color based on the pH of the solution. The resulting color can be compared to a color chart that indicates the pH level, allowing for a determination of how acidic or alkaline the mixture is.
Step 3
Explain why litmus paper would not be a suitable indicator to use in this experiment.
Answer
Litmus paper only shows if the solution is acidic or alkaline but does not provide specific pH values. Additionally, litmus paper can only change color at a limited pH range, which might not give an accurate reflection of the gradual pH changes as barium hydroxide is added.
Step 4
Plot a graph of the pH of the mixture against the mass of barium hydroxide.
Answer
On the graph, the x-axis should represent the mass of barium hydroxide (in grams), while the y-axis represents the pH of the mixture. The points based on the data provided should be plotted (e.g., (0.0, 1), (0.2, 1), (0.4, 1), (0.6, 1), (0.8, 2), (1.0, 7), (1.2, 12), (1.4, 13), (1.6, 13)). Ensure that a line of best fit is drawn through the points, depicting the trend of pH as more barium hydroxide is added.