How many grams of NaOH are needed to prepare 250 mL of 0.205 M NaOH?
2007-10-16 10:24:23 · 3 answers · asked by scr_babe07 1 in Science & Mathematics ➔ Chemistry
First, you need the molecular weight of NaOH. I believe it's about 40 g/mol.
0.205 M Naoh...M is concentration in mol/L.
So (0.205 mol/L) x (0.250 L) x (40 g/mol)...
You need 2.05 grams of NaOH.
2007-10-16 10:30:26 · answer #1 · answered by WT 4 · 0⤊ 0⤋
Atomic weights: Na=23 O=16 H=1 NaOH=40
Let the NaOH solution be called NaS
250mLNaS x 0.205molNaOH/1000mLNaS x 40gNaOH/1molNaOH = 2.05g NaOH
2007-10-16 17:30:31 · answer #2 · answered by steve_geo1 7 · 0⤊ 0⤋
760.42 grams
In a 3.4 M solution, there are 3.4 moles per liter. If you want to make 3 liters of solution, you'll need
3 liter * 3.4 moles/liter = 10.2 moles
The molar mass of KCl is
39.098 g/mole K + 35.453 g/mole Cl = 74.551 g/mole KCl
To get the number of grams, multiply the number of moles by the molar mass:
10.2 moles * 74.551 g/mole KCl = 760.4202 g = 0.760 kg
2007-10-16 17:27:21 · answer #3 · answered by mikeydonatelli 6 · 0⤊ 0⤋