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Ex 8.3
Ex 8.3, 1 (b) Important
Ex 8.3, 1 (c)
Ex 8.3, 1 (d) Important
Ex 8.3, 2 (a)
Ex 8.3, 2 (b) Important
Ex 8.3, 2 (c) Important
Ex 8.3, 2 (d)
Ex 8.3, 3
Ex 8.3, 4 Important
Ex 8.3, 5
Ex 8.3, 6 Important
Ex 8.3, 7 Important You are here
Ex 8.3, 8
Ex 8.3, 9 (a) Important
Ex 8.3, 9 (b)
Ex 8.3, 10
Ex 8.3, 11 Important
Last updated at March 23, 2023 by Teachoo
Ex 8.3, 7 (i) Chalk contains calcium, carbon and oxygen in the ratio 10:3:12. Find the percentage of carbon in chalk. Calcium : Carbon : Oxygen = 10 : 3 : 12 Total parts = 10 + 3 + 12 = 25 Percentage of carbon = (ππππ‘π ππ ππππππ)/(πππ‘ππ ππππ‘π ) Γ 100 = 3/25Γ 100% = 3 Γ 100/25 % = 3 Γ 4% = 12% Ex 8.3, 7 (ii) If in a stick of chalk, carbon is 3g, what is the weight of the chalk stick? Given, Weight of Carbon = 3g Now, We know that Carbon 12% of chalk Weight of Carbon = 12% Γ Weight of chalk 3 = 12% Γ Weight of chalk 3 = 12/100 Γ Weight of chalk 12/100 Γ Weight of chalk = 3 Weight of chalk = 3 Γ 100/12 Weight of chalk = 100/4 Weight of chalk = 25 So, Weight of chalk is 25 g Weight of chalk = 3 Γ 100/12 Weight of chalk = 100/4 Weight of chalk = 25 So, Weight of chalk is 25 g