Answer: chemical formula is CaCl2.
CaCl2------> Ca^2+ + Cl^-1
Explanation:
+2 for calcium ion and -1 for the chlorine ion.
For K2Cr2O7
The oxidation state of chromium=
(+1×2) + 2x + (-2×7) = 0
+2+2x-14= 0
2x= 12
x= 12/2
x=+6.
Therefore, the oxidation number of Chromium, Cr in K2CrO7 is +6
