J.R. S. answered 10/09/19
Ph.D. University Professor with 10+ years Tutoring Experience
(1) Mass of KIO3 needed to prepare 50.0 ml of 0.2 M solution:
molar mass KIO3 = 214.0 g/mole
50.0 ml = 0.0500 L and 0.2 M = 0.2 moles/L
mass needed = 0.0500 L x 0.2 moles/L x 214 g/mole = 2.14 g = 2 g (to 1 significant figure)
(2) Volume of 0.100 M H2SO4 needed to prepare 50 ml 0.08 M H2SO4:
V1M1 = V2M2
V1 = (x ml)
M1 = 0.100 M
V2 = 50 ml
M2 = 0.08 M
(x ml)(0.100 M) = (50 ml)(0.08 M)
x = 40. mls needed (to 2 significant figures)