Question

How many moles of `Na_2CO_3` are there in 10.0 L of 2.0 M solution?

Answer 1

There are 20. mol of `Na_2CO_3` in 10.0L of 2.0M solution.

Explanation:

Molarity is represented by this equation:

In our case, we already have the molarity and volume of solution, both of which have good units.

Let's rearrange the equation to solve for the number of moles. We can do this by multiplying by L solution on both sides of the equation. The L solution will cancel out on the right side, leaving the number of moles being equal to the molarity times volume:

Moles of solute`= L solutionxxMolarity`

Now we just plug the known values in!

Moles of solute = (10.0 L) (2.0M) = 20. moles