Question

1. the density of lead is 11.4 g/cm³ at 25°c. calculate the volume occupied by 25.0 g of lead.

2.19 cm³
285 cm³
1.24 cm³
6.05 cm³
0.456 cm³
/rong answer
question 10
0 / 2 pt

1. which of the following objects will sink when dropped into a bucket of water? given: density of water = 1.00 g/cm³

a chunk of sodium (density = 0.91 g/cm³)
a sphere of magnesium (density = 1.74 g/cm³)
a cube of aluminum (density = 2.702 g/cm³)
a chunk of dry ice (density = 1.56 g/cm³)
a diamond (density = 3.51 g/cm³)

Explanation:

Step1: Recall density formula

The density formula is $
ho=\frac{m}{V}$, where $
ho$ is density, $m$ is mass and $V$ is volume. We can re - arrange it to solve for volume $V = \frac{m}{
ho}$.

Step2: Substitute values

Given $m = 25.0\ g$ and $
ho=11.4\ g/cm^{3}$, then $V=\frac{25.0\ g}{11.4\ g/cm^{3}}\approx2.19\ cm^{3}$.

For question 10:
An object will sink in water if its density is greater than the density of water ($
ho_{water}=1.00\ g/cm^{3}$).

• A chunk of sodium has density $

ho = 0.91\ g/cm^{3}<1.00\ g/cm^{3}$, so it will float.

• A sphere of magnesium has density $

ho = 1.74\ g/cm^{3}>1.00\ g/cm^{3}$, so it will sink.

• A cube of aluminum has density $

ho = 2.702\ g/cm^{3}>1.00\ g/cm^{3}$, so it will sink.

• A chunk of dry ice has density $

ho = 1.56\ g/cm^{3}>1.00\ g/cm^{3}$, so it will sink.

• A diamond has density $

ho = 3.51\ g/cm^{3}>1.00\ g/cm^{3}$, so it will sink.

Answer:

1. $2.19\ cm^{3}$
2. A sphere of magnesium (density = 1.74 g/cm³), a cube of aluminum (density = 2.702 g/cm³), a chunk of dry ice (density = 1.56 g/cm³), a diamond (density = 3.51 g/cm³)