Please help with this chemistry conversion problem?

Question

Fluorite, a mineral of calcium, is a compound of the metal with fluorine. Analysis shows that a 2.76 g sample of fluorite contains 1.49 g calcium. Calculate the following:

(a) mass (in g) of fluorine in the sample ___

(b) mass fraction of calcium and fluorine in fluorite

(c) mass percent of calcium and fluorine in fluorite

(Please explain it to a beginner step by step so that I can figure it out on my test tomorrow... first to answer correct and thorough gets best answer... thanks so much!)

Answer 1

Fluorite is Calcium Fluoride is CaF2 as there is only Ca and F in the sample the answer to a is the mass of the F is the mass of the sample contain all of the Ca and F minus the mass of the Ca. This is 2.76-1.49 = 1.27g of F

b) the mass fraction is the amount of the materials in 1 g
So for Ca, there is 1.49g in 2.76g so the answer is 1.49/2.76 = 0.540. Doing the same for F and you get 1.27/2.76 = 0.460

c is the above represented as a percentage so just multiply the figures in b by 100 and you get 54.0% for Ca and 46.0% for F

Answer 2

Fluorine is composed of Ca and F
(a) if you have the mass of Ca the difference between total weight and weight of Ca gives the mass of fluorine else
mass of Fluorine 2.76-1.49 =1.27 g
(b) mass fraction of Fluorine 1.27/2.76 =0.461 (you divide the mass of fluorine by total mass
(c) to have the % of fluorine you multiply the mass fraction by 100 so 0.461*100 =46.1% and as the total % is 100,thye percent of mass of Ca is 100-46.1=53.9%

Answer 3

(a) To calculate the mass of flourine, we subtract since the problem tells us Flourite is made up of both Calcium and Flourine:
2.76 g Flourite - 1.49 g Calcium = 1.27 g Flourine

(b) The fractions are 1.27/2.76 for Flourine in Flourite and 1.49/2.76 for Calcium in Flourite.

(c) The mass percent for Flourine is 100% x (1.27g/2.76g) = 46.0%

The mass percent for Calcium is 100% x (1.49 g/2.75g) = 54.0%

Good luck on the test! :)