Question

Suppose you have a solution that might contain or all of the following cations: Cu2+, Ag+, Ba2+, and Mn2+. Addition of HBr causes a precipitate to form. After the precipitate is filtered off, H2SO4 is added to the supernate another precipitate forms. This precipitate is filtered off, and a solution of NaOH is added to the supernatant liquid until it is strongly alkaline. No precipitate is formed. Which ions are present in each of the precipitates? Which cations are not present in the original solution?"

Answer 1

@oOKawaiiOo

Answer 2

just need to check my answer

Answer 3

Ag+ is in the first preciptate

Ba 2+ is in the second preciptate

Answer 4

it doesnt matter which one precipitate first or last

Answer 5

for the cations question

i think the answer is the Cu, Ba and Mn are not in the original solution

Answer 6

You just have to write out what will be the compounds when you add HBr

Answer 7

let me think about it....hold on lol

Answer 8

ok

Answer 9

Before you add the H2SO4, the precipitations are CuBr2, AgBr, BaBr2, MnBr2

Answer 10

Then the remaining solution has H+, Br-, and H2O

Once you add the H2SO4, you will have H2SO4, HSO4-, SO4-2, H+, Br-, and H20 (depending on the pH)

Answer 11

When you add a strong base, it neutralized the solution and makes water. No precipitates are found since it was filtered out before adding H2SO4.

Answer 12

Sodium is the cation that isnt present in the original solution

Answer 13

before u continue i copied the wrong question i am really sorry

i will fix it right now

Answer 14

FML!

Answer 15

never mind it is right

Answer 16

sorry i was in a hurry becuz i wanted to ask u the question before u become offline

Answer 17

ok so going back to this i used this website to help me

http://answers.yahoo.com/question/index?qid=20080928203109AAc4GxM

Answer 18

Yeah use that website! oops in my answers

Answer 19

but i do not get the last part for the cations

are the supposed to be Mn+ and Cu+2 and also Ba+ since the question asks for the original solution or is it just Mn+ and Cu+2 only

Answer 20

Mn2+ Cu2+ only

Answer 21

SO4 -2 will pair with the cations 1:1 ratio

Answer 22

yeah but the question is asking about the cations that will not produce a preciptate when mixed with HBr

Answer 23

@oOKawaiiOo

Answer 24

Its the Mn2+ Cu2+ because of the 2+ charge

Answer 25

but when Ba gets mixed with HBr is does not create a solid

Answer 26

@oOKawaiiOo

Answer 27

Good catch there......if you read the question..... when you add the H2SO4, the solution becomes super alkaline and Ba2+ is an alkaline. So it tells you that the Ba has reacted with the H2SO4 and not the Mn or the Cu

Answer 28

but the question is referring the original solution which is HBr not H2SO4

Answer 29

@oOKawaiiOo

Answer 30

Its the ones are that did not precipitate....

Answer 31

The ones that didnt bind to anything

Answer 32

in the originial solution HBr right?

Answer 33

Yeah

Answer 34

so Cu Mn and Ba not only Cu and Mn

Answer 35

becuz BaBr2 is not a preciptate

Answer 36

its Cu and Mn

Answer 37

They didnt bind to anything.....

Answer 38

ok but Ba did not bind to the first solution either so should not it be included

Answer 39

H2SO4 binded with Ba2+