What is the molarity of a solution prepared by dissolving 30.0 grams of naoh in enough water to make a solution with a total volume of 2.40 liters?
0.150 m naoh
0.218 m naoh
0.313 m naoh
0.462 m naoh

0.313 M NaOH

Explanation:

Remember that Molarity is the concentration of a solution and is represented by:

Let's take your problem into account. The given is the following:

30.0 g of NaOH

2.40 L of solution

Molarity = ?

You are given the solute in grams, so you need to figure out how many moles there are in the given mass of solute. To do this, you need to first solve the molar mass of the solute.

NaOH

Element     # of atoms         Atomic Mass        Total

   Na                   1           x          22.99         =   22.99

    O                    1           x          16               =    16.00

    H                    1           x            1                =    1.00  

                                                                            39.99 g

So 1 mole of NaOH there is 39.99g of NaOH

We can now use this to convert the 30.00g of of NaOH to moles.

This means that there are 0.75 moles of NaOH in 30.0g of NaOH. We can use this in our molarity equation: