Each liter of an electrolyte solution contains 3.5 g sodium chloride, 1.5 g potassium chloride, 2.9 g sodium citrate (Na3 C6 H5 O7) and 20.0 g glucose (C6 H12 O6).
Calculate the molarity of each species present in the solution.
PLZ HELP.....I dont understand this!
2007-10-09 19:33:27 · 1 answers · asked by sweaty teddy 4 in Science & Mathematics ➔ Chemistry
Look up or calculate the molecular mass of each compound. Divide the mass of that compound by its molecular mass to find the number of moles of that compound. Since this is in one liter, that number is also the molarity (moles per liter of solution).
For example, for sodium chloride, the molecular mass is 58.4 ( http://en.wikipedia.org/wiki/Sodium_chloride ). You have 3.5g of sodium chloride, which is 3.5/58.4 = 0.6 moles; since that is in one liter, that solution is 0.6 molar. Do the rest the same way.
If you can't find the molecular mass of the full compound, you will have to add up the atomic masses of the elements. For example, for glucose you have 6 carbons, 12 hydrogens and 6 oxygens. The molecular mass of the compound is then 6*(AM carbon) + 12*(AM of hydrogen) + 6*(AM of oxygen). You can find the AM (atomic mass) of the elements from a periodic table.
2007-10-09 19:38:17 · answer #1 · answered by gp4rts 7 · 2⤊ 0⤋