Determine the density of the following fluids and objects. make conversions where necessary to make your final answer in g/mL or g/cm3
1) 50mL of milk that has a mass of 73g
2) a one litre bottle (1000mL) of cider has a mass of 1.2kg
3) an eraser with a volume of 45cm3 and a mass of 19g
4) a cork with a volume of 14cm3 and a mass of 2g

1) δ = 1.46 g/mL

2) δ = 1.2 g/mL

3) δ = 0.422 g/cm³

4) δ = 0.143 g/cm³

Explanation:

1) V = 50 mL

∴ m = 73 g

⇒ δ = (73 g)/(50 mL)

⇒ δ = 1.46 g/mL

2) V = 1000 mL

∴ m = (1.2 Kg)*(1000 g/Kg) = 1200 g

⇒ δ = (1200 g)/(1000 mL)

⇒ δ = 1.2 g/mL

3) V = 45 cm³

∴ m = 19 g

⇒ δ = (19 g)/(45 cm³)

⇒ δ = 0.422 g/cm³

4) V = 14 cm³

∴ m = 2 g

⇒ δ = (2 g)/(14 cm³)

⇒ δ = 0.143 g/cm³

1. 1 mole of anything contains 6.022x10^23 pieces  

d  

2. a  

3. c, number  

5. 1.24x10^24atoms / 6.022x10^23atoms/mole = 2moles h2 atoms  

6. fe2br3 mass = 2moles x mass fe + 3 moles x mass br  

molar mass = grams / number of moles = g/mole  

to find moles = g / molar mass  

to find mass = g = molar mass / moles