Question

1. a piece of pvc plumbing pipe displaces 60 ml when placed into a container of water. if the pipe has a mass of 78 g, what is the density of pvc?
2. a solid magnesium flare has a mass of 1300 g and a volume of 743 cm3. what is the density of the magnesium?
3. a student performs an experiment with three unknown fluids and obtains the following measurements:

fluid a: m = 2060 g, v = 2000 ml
fluid b: m = 672 g, v = 850 ml
fluid c: m = 990 g, v = 1100 ml
draw how the fluids would be layered if they were combined in a beaker.

Explanation:

Question 8

Step1: Recall density formula

Density ($
ho$) is calculated by the formula $
ho = \frac{m}{V}$, where $m$ is mass and $V$ is volume.

Step2: Identify values

Mass of PVC pipe, $m = 78\ \text{g}$, volume displaced (which is the volume of the pipe), $V = 60\ \text{mL}$ (since $1\ \text{mL} = 1\ \text{cm}^3$, volume is $60\ \text{cm}^3$).

Step3: Calculate density

Substitute values into the formula: $
ho = \frac{78\ \text{g}}{60\ \text{cm}^3} = 1.3\ \text{g/cm}^3$.

Step1: Recall density formula

Density ($
ho$) is given by $
ho = \frac{m}{V}$, where $m$ is mass and $V$ is volume.

Step2: Identify values

Mass of magnesium, $m = 1300\ \text{g}$, volume, $V = 743\ \text{cm}^3$.

Step3: Calculate density

Substitute into the formula: $
ho = \frac{1300\ \text{g}}{743\ \text{cm}^3} \approx 1.75\ \text{g/cm}^3$.

Step1: Recall density formula

Density ($
ho$) is $
ho = \frac{m}{V}$. We need to calculate the density of each fluid.

Step2: Calculate density of Fluid A

For Fluid A: $m = 2060\ \text{g}$, $V = 2000\ \text{mL}$ (since $1\ \text{mL} = 1\ \text{cm}^3$, $V = 2000\ \text{cm}^3$).
$
ho_A = \frac{2060\ \text{g}}{2000\ \text{cm}^3} = 1.03\ \text{g/cm}^3$.

Step3: Calculate density of Fluid B

For Fluid B: $m = 672\ \text{g}$, $V = 850\ \text{mL} = 850\ \text{cm}^3$.
$
ho_B = \frac{672\ \text{g}}{850\ \text{cm}^3} \approx 0.79\ \text{g/cm}^3$.

Step4: Calculate density of Fluid C

For Fluid C: $m = 990\ \text{g}$, $V = 1100\ \text{mL} = 1100\ \text{cm}^3$.
$
ho_C = \frac{990\ \text{g}}{1100\ \text{cm}^3} = 0.9\ \text{g/cm}^3$.

Step5: Compare densities

Densities: $
ho_B \approx 0.79\ \text{g/cm}^3$, $
ho_C = 0.9\ \text{g/cm}^3$, $
ho_A = 1.03\ \text{g/cm}^3$.
Fluids with lower density float on top of higher - density fluids. So the order from top to bottom (least dense to most dense) is Fluid B, Fluid C, Fluid A.

Answer:

The density of PVC is $1.3\ \text{g/cm}^3$.

Question 9