Question

the no. of moles present in 2 litre of 0.5 M NaOH IS

Answer 1

M= 0.5
that means for 1 L of solution we have 0.5 mol of naoh
so for 2L of solution, we get 2x 0.5= 1 mol of naoh

Answer 2

Explanation:

It is known that molarity is number of moles per liter of solution and number of moles equal mass divided by molar mass.

Therefore,     molarity = $\frac{mass}{volume \times molar mass}$

                            0.5 M = $\frac{mass}{2 \times 39.99 g/mol}$

                             Mass = $0.5 M \times 2 \times 39.99 g/mol$

                                       = 39.99 g

So, number of moles = $\frac{mass}{molar mass}$

                                   = $\frac{39.99 g}{39.99 g/mol}$

                                   = 1 mol

Thus, we can conclude that the no. of moles present in 2 litre of 0.5 M NaOH is 1 mol.