Question

On calcination 80g of a marble were obtained 42 g of calcium oxide. The degree of purity of marble?

Answer 1

There are 6 ways you can draw the two marbles to include one red:

RB,RY,RW,BR,YR,WR

There are 4P2 = 12 ways to draw any two marbles

So, P(one red) = 6/12 = 1/2

Answer 2

CaCO3>>CaO + CO2 is the reaction I assume you are thinking on.

80gmarble*Zpercent*1moleCaCO3/100gCaCO3*ImoleCaO/1moleCaCO3*56gCaO/1moleCaO=42gCaO

solve for Z.

Z=42*100/80*56=93.75 percent.

check my work.

Answer 3

thank you bobpursley