State, in a stepwise fashion how 250 mL of a 0.100 M Sodium Hydroxide solution
can be made from Sodium Hydroxide pellets.
You can't! Why? Because you can't buy PURE (100% NaOH) pellets. Even if you could, while the pellets are being weighed they pick up moisture AND CO2 from the air so you aren't getting pure NaOH weighed on the balance. However, for the purpose of the problem let's assume we CAN weigh pellets of NaOH straight from the bottle and they WILL NOT pick up that dreaded water and CO2 from the atmosphere. So, how many moles NaOH do we want? That's
mols NaOH = M x L = 0.100 x 0.250 = 0.0250
How many grams NaOH is that? That's grams = mols x molar mass = 0.0250 x 40 g/mol = 1.00 g.
So weigh 1.00 g NaOH on a balance, transfer the pellets to a 250 mL volumetric flask, add some distilled water, swirl until all of the NaOH has dissolved, cool (the flask will get quite warm since dissolution of the pellets is an exothermic process), add distilled water to the mark on the flask, stopper, mix thoroughly, label, done.