Answer:
[NaCl]: 2M
Explanation:
This solution is made of NaCl therefore:
Our solute is NaCl
Moles of solute: 4
Our solution's volume is 2L
Molarity are the moles of solute contained in 1L of solution (mol/L)
[NaCl]: 4 mol /2L = 2M
We can also make a rule of three:
In 2 L we have 4 moles of solute
So, In 1 L we must have (1 . 4) /2 = 2 M