Question

Write a balanced equation for the reaction:
4A_2 + 9B_2 -> AB_3

Answer 1

Not sure where that 4 and 9 are coming from, but when you balance an equation, start with 1 as the coefficient for everything:

\[A_2+B_2 \rightarrow AB_3\]
First balance the A's - you just need to add a 2 on the products side:

\[A_2+B_2 \rightarrow 2AB_3\]
Now we have 6 B's though on the products side...to make the reactants match, add a 3:

\[A_2+3B_2 \rightarrow 2AB_3\]
And that's your balanced equation!