Which of the following is a quantitative observation?

• A. The sample smells sweet.
• B. The powder feels gritty.
• C. The temperature of the liquid is 25 °C.
• D. The solution has a blue color.

Answer: (C)

Verified step by step guidance

1. Understand the difference between qualitative and quantitative observations. Qualitative observations describe qualities or characteristics without using numbers, such as color, smell, or texture.
2. Identify qualitative observations in the options: 'The sample smells sweet,' 'The powder feels gritty,' and 'The solution has a blue color' are all qualitative because they describe sensory properties without numerical values.
3. Recognize that quantitative observations involve measurements and numerical data, such as temperature, mass, volume, or length.
4. Look at the option 'The temperature of the liquid is 25 °C.' This is a quantitative observation because it provides a specific numerical value for temperature.
5. Conclude that the correct quantitative observation is the one that includes a numerical measurement, which is 'The temperature of the liquid is 25 °C.'