Question

A 12.630 g milk chocolate bar is found to contain 8.315 g of sugar.

Part A. How many milligrams of sugar does the milk chocolate bar contain?

Part B. What will be the amount of sugar in milligrams if the size of the milk chocolate bar is reduced from 12.630 g to 4.000 g ?

Part C. Given that a 12.630 g milk chocolate bar contains 8.315 g of sugar, calculate the percentage of sugar present in 12.630 g of milk chocolate bar keeping in mind that the answer should have four significant figures (two decimal places).

Answer 1

given

mass of chocolate bar (m)=12.630 g

mass of sugar in the chocolate= 8.315 g

1 gram= 1000 milli grams

A)mass of sugar in candy in milligrams = m*1000=8315 mg

B)the ratio of sugar to candy=mass of sugar/mass of candy =8.315/12.630

the ratio will remain same as the choclate is same.

let x be the mass of sugar.

ratio when total mass is 4.000 g is = x/4.000

therefore x/4.000 =8.315/12.000

x=8.315*4.000/12.000 = 2.7716 g

C)percentage of sugar =(mass of sugar/mass of choclate)*100

=65.8353 %

rounding to 4 digits, the answer is =65.84 %

(this is because if a odd digit precceds 5 then 1 should be added and no addition if it is a even digit.)