I believe It's A. You really should check other sites like before using your points. Just a little pro tip! Another tip: give me brainliest answer pls.
Product:
C: 1
O:3
H: 2
reactant:
C: 8
H: 18
O: 2
first you need to put probably an eight in front of the Carbon.
Next, add a coefficient of 9 to Hydrogen
finally, add a 3 INSTEAD of a 2 to Oxygen
should look like:
C8H18+O3>C8O2+H9O
I believe it's alkali metals and alkaline earth metals.
We have to know the solubility of CaF₂.
The solubility of CaF₂ is: (c) 2.1 x 10-4 Molar
The general expression of solubility product of any sparingly soluble salt (having solubility S) with formula 
is: 
.
For the compound, CaF₂, x=1, y=2 So, 
=
=4S³= 3.9 x 10-11 (Given)
S³=
S³=9.75 X 
S= 2.1 X 
Molar
