pH and Indicator Data Worksheet

Question 1

Which sample is acidic at 25 °C?

1. pH 4
2. pH 7
3. pH 9
4. pH 12

Question 2

How many times as concentrated in hydronium is a pH 3 solution as a pH 5 solution? Show your reasoning.

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Question 3

Two basic aqueous samples have pH values of 8 and 10 at 25 °C. Which contains the greater hydronium concentration? Explain.

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Question 4

What generally happens to the pH of a dilute acidic solution when distilled water is added at 25 °C?

1. It decreases as hydronium concentration falls.
2. It increases toward 7 as hydronium concentration falls.
3. It remains fixed because only volume changes.
4. It increases above 7 as more acid is formed.

Question 5

What does the yellow color of indicator X establish using the table?

1. pH below 3.1
2. pH exactly 3.1
3. pH exactly 4.4
4. pH above 4.4

Question 6

Give the pH range supported by both indicator observations. State the evidence for each limit.

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Question 7

Is a pH of 7 consistent with these two observations?

1. Yes, 7 is between the limits from the indicators.
2. No, yellow X requires a pH below 3.1.
3. No, colorless Y requires a pH above 10.0.
4. No, both indicators show that the pH must be exactly 4.4.

Question 8

Name a measurement the laboratory could make to decide whether the original sample is acidic, neutral, or basic.

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