@Zainab Ashkanani, first and foremost, it should be 1M of 30% (v/v) H2O2, not (w/v), because H2O2 is a liquid.
To calculate 1M of 30% (v/v) H2O2, you need to calculate the stock concentration of the H2O2 you have using the formula-
Stock concentration =
(SG * 10 * %purity) ÷ MM
where SG = specific gravity
%purity = percentage purity
MM = molar mass
After calculating the stock concentration (expressed in M), it will be used in the formula below:
C1 * V1 = C2 * V2
where C1 = the calculated stock concentration above
V1 = ? (the volume of H2O2 to be picked from the stock bottle)
C2 = the concentration of H2O2 you want to prepare (1M)
V2 = the volume of H2O2 you want to prepare (300ml)
ASSUMING THAT the stock concentration calculated above is 10M,
Therefore from the formula-
C1 * V1 = C2 * V2
10 * V1 = 1 * 300
10V1 = 300
V1 = 30ml
Hence, to prepare 300 ml of 1M of 30% (v/v) H2O2, 30ml of H2O2 will be picked from the stock bottle and will be made up to 300ml using distilled water in a measuring cylinder i.e. 30ml of H2O2 + 270ml of distilled water.