
William W. answered 11/15/22
Experienced Tutor and Retired Engineer
You might consider the algebraic method.
For: S + HNO3 → H2SO4 + NO2 + H2O we will need to add prefix coefficients and, since we don't know what they are, we can use a variable for each:
aS + bHNO3 → cH2SO4 + dNO2 + eH2O
where "a" is the variable representing the coefficient in front of the first sulfur, "b" represents the coefficient in front of HNO3, etc then we can say the following:
a = c (because the sulfurs much match)
b = d (because the nitrogens must match)
So, now, to make our problem a little simpler, let's rewrite it using just "a" and "b" (substituting for "c" and "d":
aS + bHNO3 → aH2SO4 + bNO2 + eH2O
We can now balance the hydrogens using the variables. The number of hydrogens on the left is (b)(1) and the number on the right is (a)(2) + (e)(2) so:
b = 2a + 2e
We can now balance the oxygens. On the left we have (b)(3) and on the right we have (a)(4) + (b)(2) + (e)(1) so:
3b = 4a + 2b + e and subtracting "2b" from both sides we get:
b = 4a + e
So since b = 2a + 2e and b = 4a + e then:
2a + 2e = 4a + e
or e = 2a
Now, pick a number to start from. Let's keep it simple and say a = 1
That means e = 2
Then, using b = 4a + e we can solve for b
Unknown U.
Thank you this really helped!11/15/22