A student measures 25.0 mL of an unknown liquid ρunknown and finds its mass to be 19.5 g. What is the density of ρunknown?

• A. 0.65 g/mL
• B. 1.28 g/mL
• C. 0.78 g/mL
• D. 1.00 g/mL

Answer: (C)

Verified step by step guidance

1. Identify the formula for density, which is defined as mass divided by volume: \(\text{density} = \frac{\text{mass}}{\text{volume}}\).
2. Note the given values: mass = 19.5 g and volume = 25.0 mL.
3. Substitute the given values into the density formula: \(\text{density} = \frac{19.5\ \text{g}}{25.0\ \text{mL}}\).
4. Perform the division to calculate the density value (do not calculate the final number here, just set up the expression).
5. Express the density with the correct units, which are grams per milliliter (g/mL).