Question

A nickel compound has the formula Ni(NO3)2•xH,0 and a molar mass

Answer 1

Answer:  x = 6

Explanation:

Molar mass of a compound is the sum of the molar mass of all the atoms of the compound.

⇒ Molar mass of the Nickel Compound (Hydrated Nickel (II) Nitrate)

             = Molar mass (Ni+ 2N + 6O)+ x (2H+ O)

             = [58.693 +  2(14.007) + 6(15.999)] + x [2(1.008) + 15.999] g/mol

             = (182.701 + 18.015x) g/mol

Since the molar mass is known to be  290.7 g/mol

then  182.701 + 18.015x = 290.7

⇒                       18.015x =  290.7 - 182.701

                                    x =  (290.7 - 182.701) ÷ 18.015

∴                                   x = 6    [conventionally expressed as a whole number]

            that makes the compound Nickel Nitrate Hexahydrate