A certain ore is 32.6% nickel by mass. How many kilograms of this ore would you need to dig up to have 75.0 g of nickel?

Note:

Nickel ore has a density of about 1.6 g/cm³.

This is equivalent to

(1.6 x 10⁻³ kg) / (10⁻² m/cm) ³ = 1600 kg/m³

Because the ore yields 32.6% of nickel by mass,

1600 kg ore will yield 1600*0.326 = 521.6 kg of nickel.

Therefore, 75.0 g of nickel requires

[ (75 x 10⁻³ kg) / (521.6 kg) ] * (1600 kg ore)

= 0.23 kg ore

Answer: 0.23 kg of ore