Question

A solution contains 85.0g of NaCl, and has a volume 750mL. What is the molarity of the solution?Molar mass of NaCl=58.44g/mol

Answer 1

1.9 Molarity.

Explanation:

Well, the molarity formula is:
`"Molarity" = "Moles of Solute" / "Liters of Solution"`

So, the first thing I would do is convert the 750 mL to Liters. This would equal: .750 L (KHDBDCM: M->B).

Next, calculate the moles of NaCl by using the formula:
`"Moles" = "Amount Available" / "Molar Mass"`
So, the number of moles would be #(85.0g " of NaCl")/ ("58.44g " ("Molar Mass"))# which would equal: 1.45448323066 mol.

Next, plug the numbers into the molarity formula which would be: `(1.45448323066 " mol")/(.750" L")`

The molarity would be 1.93931097421 M.

However, don't forget significant figures, so your final answer will be 1.9 M.

Answer 2

`[NaCl] = 1.9M` (2 Sig-figs)

Explanation:

`Molarity = "moles solute"/"Volume of Solution in Liters"`

`[NaCl]` = `((85.0g)/(58.44(g/"mole")))/(0.750 L)` = `1.9393M` `~~ 1.9M`*

*(2 Sig-figs per solution volume of 750 ml.)