A solution contains Cr+3 ion and Mg+2 ion. The addition of 1.00 L of 1.55 M NaF solution is required to cause the complete precipitation of these ions as CrF3(s) and MgF2(s). The total mass of the precipitate is 49.8 g. Find the mass of Cr+3 in the original solution.

Answer 1

Let X = mass Cr^+3
Let Y = mass Mg^+2
mm stands for molar mass.
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two equations.
moles Cr + mols Mg = total moles
mass CrF3 + mass MgF2 = total mass.
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X(1/mmCr) + Y(1/mmMg) = 1.55
X(mmCrF3/mmCr) + Y(mmMgF2/mmMg) = 4.98
Solve the two equation for X and Y..
Check my work.

Answer 2

52

Answer 3

SO WHATS THE ANSWER??

Answer 4

The answer is 9.95 g