How many moles are contained in each of the following? Be sure each of your answer entries has the correct number of significant figures.

30.0 g of lithium bromide (LiBr)

30.0 g LiBr =

mol LiBr

×

Part 2 of 2

23.8 g of aspirin (C9HgO4)

23.8 g C9H8O4=

mol CoH84

1 answer

For lithium bromide (LiBr):

Molar mass of LiBr = 6.94 g/mol (for Li) + 79.90 g/mol (for Br) = 86.84 g/mol

30.0 g LiBr × (1 mol LiBr / 86.84 g LiBr) = 0.346 mol LiBr

Therefore, there are 0.346 moles of lithium bromide in 30.0 g of LiBr.

For aspirin (C9H8O4):

Molar mass of C9H8O4 = 9(12.01 g/mol) + 8(1.01 g/mol) + 4(16.00 g/mol) = 180.16 g/mol

23.8 g C9H8O4 × (1 mol C9H8O4 / 180.16 g C9H8O4) = 0.132 mol C9H8O4

Therefore, there are 0.132 moles of aspirin in 23.8 g of C9H8O4.