Question

 An empty graduated cylinder weighs 75g. When filled with 50ml of an unknown liquid it weighs 125g.  What is the density of the liquid?

a. 1.00 g/mL b. 1.67 g/mL c. 2.50 g/mL d. 4.00 g/mL

Answer 1

Since the mass of the empty cylinder is 75g, and the mass of the filled cylinder is 125g, the mass of the liquid is:

$$m = 125g-75g = 50g$$

Let $V = 50ml$ be the volume of the liquid. By definition, the density of any substance is:

$$\rho = \dfrac{m}{V}$$

Substituting the values, obtain:

$$\rho = \dfrac{50g}{50ml} = 1\space g/ml$$

Answer. a. 1.00 g/mL.