Question

1. density calculations continued (14 points) show your work!!

volume = 5ml, mass = 20g
if a substance has a volume of 30ml and a mass of 60g, what is its density?
an unknown substance has a volume of 20cm3 and a mass of 20g. what is its density?
volume = 43cm3, mass = 45g
mass = 106.26g, volume = 55ml
volume = 13cm3, mass = 147.55g
mass = 25g, volume (length = 1, width = 2, height = 2.5)

Explanation:

Step1: Recall the density formula

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

Step2: Calculate density for each case

• First case: \( m = 60g \), \( V=30mL \). Then \(

ho=\frac{60g}{30mL}=2g/mL \).

• Second case: \( m = 20g \), \( V = 20cm^{3} \). Then \(

ho=\frac{20g}{20cm^{3}}=1g/cm^{3} \).

• Third case: \( m = 45g \), \( V = 43cm^{3} \). Then \(

ho=\frac{45g}{43cm^{3}}\approx1.05g/cm^{3} \).

• Fourth case: \( m = 106.26g \), \( V = 5.5mL \). Then \(

ho=\frac{106.26g}{5.5mL}\approx19.32g/mL \).

• Fifth case: \( m = 147.55g \), \( V = 13cm^{3} \). Then \(

ho=\frac{147.55g}{13cm^{3}}\approx11.35g/cm^{3} \).

• Sixth case: \( V=\text{Length}\times\text{Width}\times\text{Height}=1\times2\times2.5 = 5cm^{3} \), \( m = 25g \). Then \(

ho=\frac{25g}{5cm^{3}}=5g/cm^{3} \).

Answer:

1. \( 2g/mL \)
2. \( 1g/cm^{3} \)
3. \( 1.05g/cm^{3} \)
4. \( 19.32g/mL \)
5. \( 11.35g/cm^{3} \)
6. \( 5g/cm^{3} \)