Question

0.4 L of a 8 M solution are poured into a beaker. 0.5 L of water is added to the beaker what is the new molarity?

Answer 1

The initial solution contains:

n = M × V

where n - number of moles, M - molarity, V - volume.

From here:

n = 8 M × 0.4 L = 3.2 mol

The final volume of the solution is:

V_final = 0.4 L + 0.5 L = 0.9 L

The new molarity is:

M_final = n / V_final = 3.2 mol / 0.9 L = 3.6 M

Answer: 3.6 M