How do I calculate the approximate NaOH concentration of 4 grams of solid NaOH in 200 mL of water? (MW=40.00)
2006-08-23 10:44:24 · 4 answers · asked by thoughtfulo 1 in Science & Mathematics ➔ Chemistry
If you want mass concentration then it's simply dividing mass of NaOH by volume of water:
mass conc. = 4g/0,20L = 20g/L
If you would like to know concentration in moles per litre, than you have to calculate the number of moles of NaOH and divide it by volume of water:
c = n/V = m/(M*V) = 4g/(40g/mol*0,20L) = 0,5mol/L
2006-08-23 10:51:19 · answer #1 · answered by Anonymous · 0⤊ 0⤋
4 grams of NaOH equals 0.10 moles of NaOH (4 g /40.00 g/mol).
0.10 mol of NaOH in 0.20 L of water = 0.50 mol/L
The actual value will be a little lower, since concentration is measured in terms of moles of solute per litre of solution. (The final volume of solution in this case will be a little more than 200 mL, since the solid NaOH will add some volume.)
2006-08-23 17:54:38 · answer #2 · answered by wibblytums 5 · 0⤊ 0⤋
g=((MxV)xMWT)/1000
So: M=gx1000/(VxMWT)
Molarity is M=4x1000/(200x40)
=0.5 M
2006-08-23 18:12:30 · answer #3 · answered by fatma m 2 · 0⤊ 0⤋
It is 0.5M. 4g/40g/mol/.2L.
2006-08-23 19:20:00 · answer #4 · answered by jsn77raider 3 · 0⤊ 0⤋