Question

Chalk contains calcium, carbon and oxygen in the ratio 10:3:12.
A) Find the percentage of carbon in chalk

B) If in a stick of chalk, carbon is 3g, what is the weight of the chalk stick

Answer 1

10x+3x+12x= 40+12+48

25x= 100

x=4

calcium =10×4=40

oxygen = 12×4=48

carbon=3×4=12

(a) percentage of carbon in chalk

= 12/100 ×100=12%

(B) if carbon 3g

then weight of chalk stick is

10+3+12=25g