How many mg of corn starch (mw=198.00 daltons) do you need to add to 10 milliliters of water in order to make a 300 mill

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How many mg of corn starch (mw=198.00 daltons) do you need to
add to 10 milliliters of water in order to make a 300 millimolar
corn starch?
Suppose you have stock solution with a solute concentration of
250 mM. if you wanted to dilute this solution to make a total of
500 microliters of a 2 mM solution, what volume of stock ____ and
what volume of water _____ would you use? Give your answers in
microliters and show your calculations.
Suppose you have stock solution with a solute concentration of a
500 mM. If you wanted to dilute this solution to make a total of
1000 microliters of a 50 mM solution, what volume of stock _____
and what volume of water ____ would you use? Give your answer in
microliters and show your calculations.