Describe the preparation of 250cm3 of 0.05M of H2SO4 solution given the following stock solution specification; % purity= 98, S.G = 1.84 and Molecular weight= 98
2 answers
Describe the preparation of 250 cm3 of 0.05M H2SO4 solution given the following stock solution specification; % purity= 98, S.G = 1.84 and Molecular weight=98
First, determine the molarity of the stock solution.
The sp.g. is 1.84 so the density is 1.84 g/mL.
Mass of 1 L of H2SO4 is 1.84 g/cc x 1000 cc = 1840 grams.
Mass of H2SO4 in that 1840 grams is 1850 x 0.98 = 1803 g
mols H2SO4 = g/molar mass = 1803/98 = 18.4 mols is 1 L; therefore, M 18.4.
Then use the dilution formula of
mL1 x M1 = mL2 x M2
mL1 x 18.4 = 250 mL x 0.05
Solve for mL1 (that's mL of the stock solution of 18.4 M), then transfer that volume of the stock into a 250 mL volumetric flask, make to the mark with distilled water, stopper, mix thoroughly and label.
NOTE: For safety you should place distilled water in the volumetric flask until it is about half filled BEFORE adding the stock solution of concentrated H2SO4. You should ALWAYS add acid to water, never water to acid.
The sp.g. is 1.84 so the density is 1.84 g/mL.
Mass of 1 L of H2SO4 is 1.84 g/cc x 1000 cc = 1840 grams.
Mass of H2SO4 in that 1840 grams is 1850 x 0.98 = 1803 g
mols H2SO4 = g/molar mass = 1803/98 = 18.4 mols is 1 L; therefore, M 18.4.
Then use the dilution formula of
mL1 x M1 = mL2 x M2
mL1 x 18.4 = 250 mL x 0.05
Solve for mL1 (that's mL of the stock solution of 18.4 M), then transfer that volume of the stock into a 250 mL volumetric flask, make to the mark with distilled water, stopper, mix thoroughly and label.
NOTE: For safety you should place distilled water in the volumetric flask until it is about half filled BEFORE adding the stock solution of concentrated H2SO4. You should ALWAYS add acid to water, never water to acid.