butterfly Posted April 9, 2004 Posted April 9, 2004 i am trying to work out these questions but i cant seem to get the right answer. any help we be appreciated. question one: Calculate the chemical amount of anions in 79.0 mL of a 0.4564 M solution of cobalt(III) chloride question 2: Calculate the concentration of anions if 100.0 mL of a 0.3530 M solution of iron(III) sulfate is diluted with water to the mark in a 500.0 mL volumetric flask
Guest honeybabes_18 Posted April 9, 2004 Posted April 9, 2004 question 1. First step, calculate mass by multiplying concentration by molar mass... Then, follow the steps i gave you in the last post until you get to the last one where you divide by the amount... except this time you MULTIPLY by the amount (0.079L) That should give you the right answer Question 2. I have no clue...
Skye Posted April 9, 2004 Posted April 9, 2004 Q2. This should work... Find the mol. wgt. of iron and sulphate, then find what percentage of their combined mol. wgt. is the sulphate, as it's the anion in this case. Multiply this by the molarity of the solution, 0.3530, to get the molarity of the sulphate. As this is diluted five times in the 500 ml flask, divide this number by five to get the conc. of the of the anions in the final solution, in mol/l.
Guest brekka Posted April 10, 2004 Posted April 10, 2004 question 1. First step' date=' calculate mass by multiplying concentration by molar mass... [/quote'] See here, do you multiply by the molar mass of cobalt(III) chloride, or just 3Cl as it is only asking for anions?
butterfly Posted April 11, 2004 Author Posted April 11, 2004 you multiply the concentration by the whole mass. then you devide the mass of 3CL by the whole mass, to get only anions.
Guest sureksha Posted April 11, 2004 Posted April 11, 2004 can someone help me plzzzzzzzz.... i tried but i cant seem to get the rite ans for ques no 2 plzzzz save me.. got an assign due tonight...............
rogue Posted April 11, 2004 Posted April 11, 2004 can someone help me plzzzzzzzz.... i tried but i cant seem to get the rite ans for ques no 2plzzzz save me.. got an assign due tonight............... Q2) Cint=0.3530M Vint=0.1 Cfin=? Vfin=0.5 n=Cint×Vint =0.0353moles so 0.0353moles=Cfin×Vfin Cfinal=0.0353moles÷0.5 Cfin=0.0706mol × 3 Final con.=0.2118mol/L
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