In order to find th mass in grams of 4 moles of Li2S, we need to use its molar mass, 45.95g/mol and the provided number of moles, the calculation is:
45.95g = 1 mol of Li2S
x grams = 4 moles of Li2S
x = 183.8 grams of Li2S in 4 moles, which can be rounded to184 grams, letter D