Answer:
0.30 mole NaCl needed.
Explanation:
From the definition of solution molarity => Molarity = moles solute / Volume of Solution in Liters => Molarity = moles/Volume(L) => solve for moles =>
moles = Molarity X Volume(L) = (0.1M)(3.0L) = 0.30 mole NaCl needed.
