# A graduated cylinder is filled with water to a level of 40.0 ml. When a piece of copper is lowered into the cylinder, the water level rises to 63.4 mL. What is the volume of the copper sample? If the density of the copper is 8.9 g/cm^, what is its mass?

Jan 3, 2018

Well, the volume of the copper is $\left(63.4 - 40.0\right) \cdot m L = 23.4 \cdot m L$

#### Explanation:

Do you agree? The copper displaces the given volume of water.

Now ${\rho}_{\text{Cu}} = 8.90 \cdot g \cdot c {m}^{3}$ OR ${\rho}_{\text{Cu}} = 8.90 \cdot g \cdot m {L}^{-} 1$, i.e. $1 \cdot m L \equiv 1 \cdot c {m}^{3}$

But by definition, ${\rho}_{\text{density"="mass"/"volume}}$

And thus $\text{mass"=rhoxx"volume} = 8.90 \cdot g \cdot \cancel{m {L}^{-} 1} \times 23.4 \cdot \cancel{m L}$

$= 208.3 \cdot g$. Do you follow?