Question

CuSO4(aq) + 2NaOH(aq) Cu(OH)2(s) + Na2SO4(aq)
ii. If 638.44 g CuSO4 reacts with 240.0 NaOH, which is the limiting reagent? (.5 point)
CuSO4 = 638.44 g divided by 159.62 g/mol = about 4 moles
NaOH = 240 g divided 40 g/mol = about 6 moles
limiting reagent is NaOh correct?

Answer 1

it is, now what?

Answer 2

Use the limiting reagent to determine how many grams of Cu(OH)2 should precipitate out in the reaction.

Answer 3

it has to be 6 times the molar mass of Cu(OH)2 right?

Answer 4

do'nt skip the mole ratio

Answer 5

right i forgot about that

Answer 6

hold on i need to rewrite this on a sheet of paper

Answer 7

wait, wouldnt CuSO4 be the limiting because it has 4 moles which is less than the 6 moles of NaOH

Answer 8

nope naoh since the molar ratio is 1 to 2, meaning molar ratio 1 is 4 moles for cuso4 and 3 moles for naoh

Answer 9

right...?

Answer 10

your original logic is correct.

Answer 11

because of the 1:2 molar ratio, if you have 4 moles of CuSO4, you'd need 8 moles of NaOH to use it all, since 4:8 = 1:2.

You don't have 8 moles of NaOH, you only have 6, so NaOH is the limiting reagent

Answer 12

yea but you could figure out the molar ratios

Answer 13

it'd be 4 for cuso4 and 3 for naoh

Answer 14

Use the limiting reagent to determine how many grams of Cu(OH)2 should precipitate out in the reaction.

Answer 15

is the limiting reagent 6 or 3..? moles

Answer 16

doesn't the molar ratio have t be calculated...

Answer 17

and then multiply that by the molecular mass of Cu(OH)2

Answer 18

the limiting reactant is the 6 moles of NaOH. 3 moles of Cu(OH)2 produced is the yield

Answer 19

i think its incorrect because when i did a similar problem yesterday, i used the molar mass of the limited reagent

Answer 20

4mol CuSO4
6mol NaOH

Formula
CuSO4(aq) + 2NaOH(aq) -> Cu(OH)2(s) + Na2SO4(aq)

If you go by Cu(OH)2 you have 4mol Cu(OH)2
If you go by NaOH you have 6mol/2 or 3mol Cu(OH)2

thus NaOH is the limiting reagent, because it produces less product.

Whenever using the equation to find moles of another substance from the moles of a substance you know, you always divide by the number next to the molecule or atom and multiply by the number next to the molecule or atom you want to convert to

Answer 21

then you did the problem yesterday incorrectly. You have moles of NaOH REACTANT, so now use the molar ratio to find the moles of copper hydroxide PRODUCT

Answer 22

so my point is, Cu(OH)2 gives 4mol Cu(OH)2. and i would multiply this by 159.6086

Answer 23

Use the limiting reagent to determine how many grams of Cu(OH)2 should precipitate out in the reaction.
so wouldn't i just do 4 x molar mass of cuso4 which is 159.6086

Answer 24

you won't make 4 moles of Cu(OH)2, you'll only make 3 moles. The 6 moles of NaOH and the 2:1 ratio determine you'll make only 3 moles of Cu(OH)2

Answer 25

oh so its 3 x 159.6086

Answer 26

yes, GJ