acheiver gchem

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utdent20

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Which of the following pairs would most accurately produce a 10 Which of the following pairs of sample compounds would most accurately produce a 10% HNO3 acid?
A. 10 g HNO3 and 90 g H2O B. 10 g HNO3 and 100 g H2O C. 10 ml HNO3 and 90 ml H2O D. 10 ml HNO3 and 100 ml H2O E. 10 g HNO3 and 100 ml H2O

Any one got explanations on this...??

What would be the percentage yield if 11 What would be the percentage yield if 11.85 g of Na2S2O3 were obtained from a reaction mixture containing 12.60 g of Na2SO3 and 5.00 g of S? Na2SO3 + S à Na2S2O3

A. 55% B. 60% C. 65% D. 70% E. 75%please explain the working procedure..

also.. What do you all know about Kinetic Energy ?
Any clue on what is thermodynamically favorable and non favorable? i believe there is question like that in the destroyer somewhere.. to tired to look up which one.
Also how do you all remember the difference between the galvanic /electrolytic cell.. on avhiever its asking for A Daniel CELL??? what is that.. Ok lots of questions..help me ou thanks guys

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ill only answer the first question. the others, do the math or look it up. if your lazy why should we not be?
anyway its D because we want our answer to be in ml not g because its percentage of solution. and its D because 10% of 100 is 10 and not C because 10% of 90 is 9 comprende?
 
The answer to the first one is A as stated. The reason for this is because percent is percent by mass. Now if you are 10% HNO3 then you have 10g of HNO3 for every 100g of solution. That means that you have 90g of H2O to make up the 100 grams solution.
 
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For the second one, it is a basic limiting reagent problem. What you would do is calculate the limiting reagent which you do by converting to moles and then seeing if ou have enough of a particular one. (I dont have a periodic table handy so i cant solve.) Then once you figure out your limiting reagent you plug it into your equation and do dimensional analysis to calculate your theoretical yield. Once ou get the theoretical yield you would do actual/theoretical yields * 100 and that would give you the percent yield.
 
i was wondering if anyone can solve the limiting reagent problem. I can't get the right answer and i tried to do it twice. So i must have missed something...
 
If someone can supply the atomic masses for all of the atoms involved, perhaps I can solve it when i have a moment free.
 
Hi Thanks
I actually just solved it. I didn't read the M.W. correctly...
The answer is 75% right?
 
I have no idea, i dont have the atomic masses. However if you did it right then there is no reason why your numbers should be wrong.
 
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