/sci/ - Science & Math

[Anonymous No.3761129]

Hey, /sci/. I know you aren't homework help, but my first college chemistry test is coming up and I was wondering if there's a simple way to balance an equation like this:

S + HNO3 -> H2SO4 + NO2 + H2O

Any advice?

[Anonymous No.3761142]

0S + 0HNO3 -> 0H2SO4 + 0NO2 + 0H2O

Checkmate, chemistry.

[EK !EKFQOBUFnQ No.3761143]

i don't think there is a shortcut. just do it by observation.

S + 6HNO3 → H2SO4 + 6NO2 + 2H2O

[EK !EKFQOBUFnQ No.3761146]

>>3761142

[Anonymous No.3761168]

well a safe way would be by .... dunno the english name oxygen count / lvl (oxidationszahlen someone transalte!) of the parts

e.g. S is in its elementary state of 0
H= +1 O= -2 N= +5

This way you can track the way of the elections if some electrons gone mission yo+ve done something wrong

[Anonymous No.3761172]

Look at the elements that are only in one atom on each side. Sulfur is on its own on the left, so you know you can do that last. You know that there are going to be the same number of HNO3's as NO2's because they are the only ones with nitrogen. Then, the number of hydrogens must be equal, so I would start by trying 4HNO3 and just having the right side be as is with 4NO2 as stated earlier. That would mean that there was 12 oxygens on the left and 13 oxygens on the right. That means you need more oxygens on the left, So I would try going up to 6HNO3, because you can only increase the number of hydrogens on the right by two at a time. This yields 6NO2, and to balance out the hydrogen, 2H2O, which is the correct balanced equation. Hope that helps.

[EK !EKFQOBUFnQ No.3761173]

>>3761168

[Anonymous No.3761176]

>>3761168
oxidation state / oxidation number

[Anonymous No.3761185]

>>3761168
When you need english words, go to your wikipedia and search for the term in your language. Then switch to english.

[Anonymous No.3761227]

If you're looking for an algorithm that will solve every scenario:

(1) Give every item a variable. In your case, S's constant is a, HNO3 is b, H2SO4 is c and so on.

(2) For every element involved, do the following:

(2A) For each term, multiply the constant by how much of that element there is. When doing S, for a you would get a*1=a from S. From HNO3 you would get b*0 (no S in HNO3) = 0. When doing O you would get a*0 and b*3 respectively.

(2B) For the left side, add up all of these, write equals, add up the ones on the right. For O you would get a*0+b*3=c*4+d*2+e*1.

(3) You know have a system of linear equations! Solve for smallest integers like you learned in elementary school. Replace variables with their values.

If you want it to assign fractions to elements, like 1/2 for oxygen in water hydrolysis, you can do some wizardry by treating things like O2 as if they were O and then /2 ing the resulting number.

[Anonymous No.3761420]

I suck at teaching :| how do people not get this.

Just make the same amount of shit on one side equal out to other side.