Question

2 HOCl + 2 C2H4O2 = Cl2 + 2 C2H3O2 + 2 H2O

from these equation how to calculate the mass of HOCl and C2H4O2 to produce 5ppm of chlorine gas?

Answer 1

yeah, first make sure that the reaction is balanced

Answer 2

then get your periodic table of elements, because you will be calculating moles and converting them into grams

Answer 3

now if that reaction is already balanced (something you will have to make sure) you are looking at Cl2 and it tells you that for the reactants on the left hand side yields 1 mole of Cl2

make sure you know the mass of Cl2

Answer 4

the equation is balanced.

Answer 5

how many grams are there in a mole of Cl2

Answer 6

70.906 gram

Answer 7

how many ppm is that?

Answer 8

1 ppm = 0.001 grams

Answer 9

i tell based on the molar mass actually....if 70.906 gram means it will be 70906 ppm?

Answer 10

yeah because you move the decimal point to the right three times

Answer 11

you only need 5, so that means you need a smaller amount of reactants

Answer 12

WHAT?

Answer 13

sorry how u know 1ppm = 0.001g?

Answer 14

my bad, I was thinking of something else
0.001g/litre = 1 ppm

Answer 15

so 1mg/l = 1ppm am i right?
so how to solve this??

Answer 16

dynamic conversion

Answer 17

dynamic conversion means?

Answer 18

i need to find the mass of hocl and c2h4o2 to produce 5 ppm of cl gas.....

Answer 19

\[5 \times (\frac{0.001g}{1L}) = 5ppm\]

Answer 20

you have to look at the reaction and reactants
your reactants yield 1mole of Cl2

Answer 21

yes two mole of hocl and c2h4o2 produce one mole of cl2..but how to calculate..:(

Answer 22

http://chemwiki.ucdavis.edu/Analytical_Chemistry/Chemical_Reactions/Limiting_Reagents

Answer 23

have you learned this part?

Answer 24

your reactants are 2:2
so that means it is a 1:1 ratio

Answer 25

i dont actually

Answer 26

a 1:1 ratio is easy to work with
just like when you need 1 table spoon of sugar for every 1 table spoon of flour when baking that yields 2 table spoon of doughnut
and if you want 5 table spoon of doughnut you will have to increase your sugar and flour
your ratio starts with 1:1:2
now you want x:y:5
first,
(1:1:2)/2 = 0.5:0.5:1 since we want 5, we multiply by 5
5(0.5:0.5:1) = (2.5:2.5:5)

Answer 27

now with what you have, you have more than 1 reactions but you only need to worry about the Cl2
so with 2:2:1 all in moles
1 mole of Cl2 = 70.906g of Cl2
70.906 g Cl2 = 70906mg of Cl2

you just need 5.0 grams of Cl2 in a litre to make 5 ppm


(70906/1L) but needs 5/1L
since they both need to be in Litre anyway, we can drop that for now

70906x = 5
solve for x

remember that you don't yield Cl, but instead you are yielding Cl2 and that is something you need to account for
Cl2 -> Cl+Cl

Answer 28

now a more systematic approach would be, instead of using moles, use grams.

convert the moles of the reactants into grams
A:B:C
you already know C (assuming that you will use that as your Cl2)

Answer 29

2:2:1
2A:2B:1C
1A:1B:0.5C
0.5A:0.5B:0.25C
are you getting this ratio technique?

Answer 30

yes i get this........

Answer 31

sorry
how many moles of Cl2 do you need to get 5mg of Cl2?

Answer 32

0.07 mole of chlorine

Answer 33

thanks alot @nincompop i able to solve this question already...... :)
2 HOCl + 2 C2H4O2 = Cl2 + 2 C2H3O2 + 2 H2O

in order to produce 5 ppm of chlorine gas we need to the moles first...
5ppm = (5mg/L)*(1mole/7.09mg) = 0.0705mol/L

from the ratio theoram 2:2:1=(0.141:0.141:0.0705)
now we find the mass of
HOCL = 0.141*52.4603 = 7.397 mg/l
c2h4o2 = 0.141*60.05196 = 8.47mg/l