Question

desperate help needed :) find the mass of this solute - 200ml of 1.5M sodium hydroxide- explanation plz :)

Answer 1

Right, from me you always get an explanation:
We need 2 very simple equations here:
\[\LARGE C=\frac{ n }{ V }\]
\[\LARGE n=\frac{ m }{ M }\]
Here is:
C: the concentration [M = mol/L]
n: the amount of substance [mol]
V: the volume [L]
M: the molecular mass [g/mol]
m: the mass [g]

Answer 2

12 g

Answer 3

We notice we have a concentration and a volume. from that we can calculate the amount of substance:
\[\LARGE n=CV\]
When we have that number we can simply use it in the other equation and solve for the mass:
\[\LARGE CV=\frac{ m }{ M } \to m=CVM\]

Answer 4

thankyou :)

Answer 5

Oh yea and M(NaOH) is almost equal to 40 gram / mol... but you know how to find it your self?

Answer 6

you mean to find the mol about of sodium hydroxide yeah :) yes

Answer 7

No I mean the molecular mass:
\[\large M(NaOH)=M(Na)+M(O)+M(H )\approx 40 \frac{ g }{ mol }\]

Answer 8

yes i meant that all good thanks

Answer 9

Perfect, not problem at all.

Answer 10

:)