This is a dilution that requires a certain volume from the stock solution to be diluted with distilled water to make a solution of HBr with a lesser concentration than the stock solution
Following dilution formula can be used
c1v1 = c2v2
Where c1 is concentration and v1 is the volume of the stock solution
c2 is concentration and v2 is volume of the diluted solution to be prepared
Substituting these values
10.0 M x v1 = 3.0 x 450.0 mL
v1 = 135.0 mL
A volume of 135.0 mL from HBr stock solution needs to be taken and diluted with distilled water upto 450.0 mL. The resulting solution will have a concentration of 3.0 M
