How many grams of LiBr are in 450mL of a 3.2 M solution

Answer 1

We know that M = moles/liter

We are given the molarity of 3.2M

We are given 450ml which converts to 0.450L by the conversion shown:

450ml × (1L/1000×ml) = 0.450L

Now, using the equation M=moles/liter we can substitute and solve for moles as shown below:

3.2M = xmoles/0.450

x = 1.44 moles

No, we know that 1.44 moles of LiBr are int he solution, we can calculate the number of grams by using the molar mass of LiBr as shown below:

molar mass of LiBr = (6.94 g/mol Li + 79.9 g/mol Br) = 86.84 g/mol LiBr

Now to convert moles to grams we can do a simple dimensional analysis:

1.44 moles LiBr × (86.84 g/mol LiBr) = 125.05 g LiBr