Consider the following reaction:
3 Br2 + 6 OH¹-5 Br¹ + BrO3¹ + 3 H₂O
If 4.68 moles of Br2 are reacted with 8.12 moles of OH¹, how many moles of Br
can be formed? (Report your answer to two places past the decimal point.
Moodle is looking for a number only, no units.)

Respuesta :

Answer:

Explanation:

I'm assume that 3 Br2 + 6 OH¹-5 Br¹ + BrO3¹ + 3 H₂O is meant to read:

3 Br2 + 6 OH^-1    =   5 Br^-¹ + BrO3^-¹ + 3 H₂O

The balanced equation tells us that 3 moles of Br2 will react with 6 moles of OH^-1 to produce 5 moles of Br^-1.

The first step is to determine whether the Br2 or OH^-1 are limiting reagents.  That is, is there enough of each to complete the reaction, with none left over.

We need 3 moles of Br2 for every 6 moles of OH^-1, a molar ratio of 1/2 (Br2/OH).

We are given 4.68 moles of Br2 and 8.12 moles of OH^-1.  That is a ratio of 4.68/8.12 or 0.5764.  This is higher than the ratio of 1/2 or 0.5 that is required.  That means we have more than enough Br2.  The limiting reagent is the OH^-1.  Once it is consumed, the reaction stops and we are left with some unreacted Br2.

So we need the molar ratio of the OH^-1 to the Br from the balanced equation:  We see that 6 moles of OH^-1 are required to produce 5 moles of Br, a 6/5 molar ratio.

Therefore, we may assume all 8.12 moles of the limiting reagent, OH^-1, will be consumed to produce *6/5) that amount of Br.

(8.12 moles OH^-1)*((6 moles Br)/(5 moles OH^-1)) = 9.75 moles of Br.

For curiosity's sake, we can determine the amount of unreacted Br2.  8.12 moles of OH^-1 would require (8.12 moles OH)*(1/2) = 4.06 moles of Br2.

4.68 moles starting Br2

4.06 moles consumed

0.62 moles remaining Br2