Answer
There are $0.0505$ moles of $NiCl_2 ∙ 6H_2O$ in 12.0g.
Work Step by Step
Calculate the molar mass for: $NiCl_2 ∙ 6H_2O$
58.69* 1 + 35.45* 2 + 6 * ( 1.01* 2 + 16.00* 1 ) = 237.71g/mol
Find the number of moles in 12.0 g:
$12.0 g \times \frac{1 mole}{237.71 g} = 0.0505$ $moles$