chemistry
posted by ellen on .
need help with these problems:
The concentration of glucose in blood is usually about 0.10% (w/v). If 7.0 L of blood are in an average man, how many grams of glucose are in his blood?
To obtain the solute for 118 g of a 19.2% (w/w) solution of sugar we would weigh out ________ g of sugar.
How many moles of sodium chloride are in 993 mL of a 2.88 M solution of sodium chloride?
A salt solution is evaporated to dryness. If 79.4 g of the solution leaves 1,015 mg of dry salt, what is the percent concentration (w/w) of the salt in the solution?

0.1% w/v is 0.1 g/100 mL.
(0.1/100 mL) x 7000 mL = ?g glucose.
(grams solute/grams soln) x 100 = % w/w
(g solute/118) x 100 = 19.2
Solve for g solute.
M = mols/L by defnition.
Substitute M and L (convert 993 mL to L) and solve for moles.