What is the electron configuration for the transition metal ion in each of the following compounds? [Ni(H2O)6]Br2
[Cr(H2O)4(NO2)2]I

1)Ni=1s2, 2s2, 2p6, 3s2, 3p6, 4s0, 3d10 called full-filled

2)Cr=1s2, 2s2, 2p6, 3s2, 3p6, 4s1, 3d5 called half-filled

First, we must calculate the moles of lithium ions required using:
Concentration = moles / liter
500 ml = 0.5 L
0.125 = moles / 0.5
moles = 0.0625

Lithium phosphate has the formula Li₃PO₄, meaning each mole of lithium phosphate releases three moles of lithium ions. The moles of lithium phosphate required will be:
0.0625 / 3 = 0.021 mol

The mass of one mole of lithium phosphate is 116 g/mol
Mass of lithium phosphate required = 0.021 x 116
Mass of lithium phosphate required = 2.42 grams