Question

1a) if you have 8.00M sulfuric acid solution, and you took 20ml of this stock solution and diluted to 500mL total, what is the concentration of the dilute solution? discuss your steps when you give the answer

1b) now, If you have 8.00M of sulfuric acid solution and you want to dilute to 400mL diluted solution with concentration of 2.0M; what volume of the stock solution you should use? what volume of solvent you need to add when you dilute it

Answer 1

1a) Let for Stock solution Molarity M1 = 8.0 M and Volume (taken for dilution) V2 = 20.0 mL.

And for the solution to be prepared, Molarity M2 = ? Voolume V2 = 500.0 mL

By Law of dilution,

M2V2 = M1V1

On putting all knwn data,

M2 * 500.0 mL = 8.0 M * 20.0 mL

M2 = 8.0 M * 20.0 mL / 500.0 mL

M2 = 0.32 M

Concentration of the solution formed is 0.32 M.

1b) Let for the solution to be formed by dilution, M2 = 2.0 M and Volume V2 = 400.0 mL

And for stock solution say, M1 = 8.0 M and V1 = ?

By law of dilution,

M1*V1 = M2*V2

On putting known vvalues,

8.0 M * V1 = 2.0 M * 400.0 mL

V1 = 2.0 M * 400.0 mL / 8.0 M

V1 = 100.0 mL

100.0 mL of 8.0 M H2SO4 when diluted to 400.0 mL (by adding 300.0 mL Distilled water) will give 2.0 M solution.

300.0 mL of solvent (DW) need to be added to 100.0 mL of 8.0 M H2SO4 stock.

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