Comments on: Chem Question 10 points will be given to best answer? http://eatpotassiumrichfood.com/healthy-diet/chem-question-10-points-will-be-given-to-best-answer/ A Healthy Eating Guide Wed, 08 Feb 2012 17:49:46 +0000 http://wordpress.org/?v=2.7.1 hourly 1 By: Trevor H http://eatpotassiumrichfood.com/healthy-diet/chem-question-10-points-will-be-given-to-best-answer/comment-page-1/#comment-6940 Trevor H Sun, 28 Feb 2010 00:01:34 +0000 http://eatpotassiumrichfood.com/healthy-diet/chem-question-10-points-will-be-given-to-best-answer/#comment-6940 You have the mass of each compound in 200ml solution. Surely the mass in 1 litre of solution (= 1000ml ) must be 5 times each mass: NaCl = 0.47*5 = 2.35g KCl= 0.30*5 = 1.5g C6H12O6 = 3.56*5 = 17.8g Now that you have the mass per litre of solution, it is easy to work out the molarity Molar mass NaCl = 23+35.5 = 58.5g/mol 2.35g = 2.35/58.5= 0.040mol dissolved in 1 litre solution: So Molarity NaCl = 0.040M Molar mass KCl = 39 +35.5 = 74.5g/mol 1.5g KCl = 1.5/74.5 = 0.020 mol in 1 lutre solution: So Molarity of KCl = 0.020 Molar mass C6H12O6 = 6*12+12*1+16*6 = 180g/mol 17.8g C6H12O6 = 17.8/180 = 0.099 I am sure your teacher will accept: Molarity of C6H12O6 solution = 0.1M Concentration of K+ ions: You have calculated that KCl solution is 0.02M KCl contains 1 atom K, So Molar concentration of K+ ions = 0.02M You have a contribution of Cl- ions from NaCl (0.04M ) and the KCl, (0.02M) so the total concentration of Cl - ions = 0.06 Molarity of Cl- ions = 0.06M You have the mass of each compound in 200ml solution. Surely the mass in 1 litre of solution (= 1000ml ) must be 5 times each mass:
NaCl = 0.47*5 = 2.35g
KCl= 0.30*5 = 1.5g
C6H12O6 = 3.56*5 = 17.8g

Now that you have the mass per litre of solution, it is easy to work out the molarity
Molar mass NaCl = 23+35.5 = 58.5g/mol
2.35g = 2.35/58.5= 0.040mol dissolved in 1 litre solution: So
Molarity NaCl = 0.040M

Molar mass KCl = 39 +35.5 = 74.5g/mol
1.5g KCl = 1.5/74.5 = 0.020 mol in 1 lutre solution: So
Molarity of KCl = 0.020

Molar mass C6H12O6 = 6*12+12*1+16*6 = 180g/mol
17.8g C6H12O6 = 17.8/180 = 0.099 I am sure your teacher will accept:
Molarity of C6H12O6 solution = 0.1M

Concentration of K+ ions: You have calculated that KCl solution is 0.02M
KCl contains 1 atom K, So
Molar concentration of K+ ions = 0.02M

You have a contribution of Cl- ions from NaCl (0.04M ) and the KCl, (0.02M) so the total concentration of Cl - ions = 0.06
Molarity of Cl- ions = 0.06M

]]> By: eat cheese http://eatpotassiumrichfood.com/healthy-diet/chem-question-10-points-will-be-given-to-best-answer/comment-page-1/#comment-6941 eat cheese Sun, 28 Feb 2010 00:01:34 +0000 http://eatpotassiumrichfood.com/healthy-diet/chem-question-10-points-will-be-given-to-best-answer/#comment-6941 people on here cant even calculate 2+2 people on here cant even calculate 2+2

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