Question

Please, please help me fast, fast, fast!

Answer 1

If 4.8 moles of X and 3.4 moles of Y react according to the reaction below, how many moles of the excess reactant will be left over at the end of the reaction?

3 X + 2Y --> X3Y2

A) 1.7 mol Y left over
B) 1.6 mol X left over
C) 0.2 mol Y left over
D) 0.1 mol X left over

Answer 2

compare the moles you have to the molar ratio from the balanced reaction.

Answer 3

the balanced reaction says 3X:2Y

Answer 4

Normally on these you just subtract or work it out like a math problem, but you can't do that on this one.. The ratio is 3:2, right?

Answer 5

you HAVE 4.8X:3.2Y. Does that equal 3:2?

Answer 6

Yes.

Answer 7

check again

Answer 8

sorry, should be 3.4 moles of Y

Answer 9

Well, I'm better at math. In my head they were both divisible by 1.6. So no, I guess for this they are not.

Answer 10

4.8X:3.4Y is not the same ratio as 3X:2Y

Answer 11

if you multiply 3.4 by 1.5, what do you get?

Answer 12

Oh, that makes more sense. Lol. 5.1

Answer 13

do you have 5.1 moles of X? No, you've only got 4.8. So which is the limiting reactant?

Answer 14

X?

Answer 15

it is. Now how much Y will be used when all the X is used up?

Answer 16

3.4?

Answer 17

multiply the limiting reactant by the mole ratio

Answer 18

7.2?

Answer 19

\[ 4.8 moles X * \frac{2 moles Y used}{3 moles X used}\]

Answer 20

Oh, oops. 3.2!

Answer 21

exactly

Answer 22

so using 4.8 moles of X will also use 3.2 moles of Y

Answer 23

You HAVE 3.4 moles of Y available, and will USE 3.2 moles. How much is left over?

Answer 24

Oh, got it. So that's the excess, and we will have 0.2mol left overrrr. Yay.
Thank you so much! God bless youuuu! <3

Answer 25

not god, science ;-)

Answer 26

Jeeeesus. And that's a capitol G, sirrr.

Answer 27

if it makes you happy

Answer 28

answer is 0.2 mole of Y left over