Question

question 7 points 2 which method can a student use to compare an unknown liquid with a known substance? mix it with another liquid randomly measure boiling point or density observe color only assume it is the same as water

Explanation:

• Mixing randomly (first option) is not a scientific method for comparison and may cause unwanted reactions.
• Measuring boiling point or density (second option) is valid because these are characteristic properties of a substance, unique (or with a known range) for each pure substance, so comparing these values with a known substance helps identify or compare the unknown.
• Observing color only (third option) is insufficient as many substances can have the same color, so it’s not a reliable comparison method.
• Assuming it’s water (fourth option) is unscientific as the unknown could be any liquid.

Answer:

B. Measure boiling point or density