Question

The hydrated chloride of a divalent Metal loses 14.73% (by weight) of its mass by dehydration .If one mole of the hydrated salt contain 2 moles of water of hydration calculate the weight % of chlorine in the hydrated salt?

Answer 1

:/ Sorry.

Answer 2

so if the metal chloride is divalent, (let the metal be 'M') - what would the chemical formula of the compound be?

Answer 3

@open_study1 - yeah so whaddya think now?

Answer 4

Hmm hmm? any idea?

Answer 5

i founded the Molar mass then what should i do??? @heena plzz help

Answer 6

molar mass of ...?

Answer 7

ok let the divalent chloride be XCl2 now they said 14.3% is loss by weight now if one mole of salt contain 2mole water and u knw evry mole of water it is 18 means 2mole 2x18=36 so we came to know by total mass u have to just reduce 36 and thats all given in qn now think by the above info wat u can do?

Answer 8

I got Molar Mass = 137.4

Answer 9

then

Answer 10

after subtracting the amount of water u got 137.4 :?

Answer 11

say?

Answer 12

@open_study1 u have provided the compound name too otherwise hoe can u get molar mass u can only get amount of percent :O

Answer 13

sorry thats not molar mass it is the weight of metal 137.4

Answer 14

@heena sorry!!

Answer 15

ok u knw 137.4 means metal name is barium now qn is easy see the salt is BaCl2

Answer 16

ok then wat to do....

Answer 17

ok nw u kne molecualr wight of bacl2
let percent be 100% from which 14.73% is removed means how much remain?

Answer 18

85.27

Answer 19

ok thanzz i got it...... 29%

Answer 20

ok den :)

Answer 21

@heena thanxx for helping

Answer 22

@open_study1 may i ask u one qn whenever i came online i instantly get a call by u i mean do u wait for me to come ?? lol :D :D everytime as i came online i get a call :P :P anyways i love to help u as u really need it as other only post their home work qn -_-

Answer 23

Lol why are we making this so complicated?

Okay now what we do is- (we don't even need the name of the metal)

\[\text{You know that the metal is something of the form } MCl_2\]

Now, every mole of the hydrated salt has two moles of H2O in it.\[\text{So, the molecular formula of the hydrated form = }MCl_2.2H_2O\]

Now when you are dehydrating one mole of the salt, you are making it lose 2 moles of water, or 36 grams of water.

Now, is the weight of of one mole of the salt 9hydrated) is 'x' grams, this '36 grams' is the 14.73% of the weight that each mole uses.


so, 14.73% of 'x' = 36
Calculate 'x'.

Now this salt contains 2 moles of the Cl atom per mole of itself. That is, 35.5 x 2 = 71 gms per mole.

so find out then what percentage of 'x' is 71 grams.
That 'll get you the mass percentage of Cl in the salt (hydrated).

Answer 24

Oh lol, you folks are done it seems. never mind.

Answer 25

v.good itna time lete ho qn solve krne m :O u knw its dangeours to take much time..

Answer 26

anyways i didnt solve this qn i m only giving hint to him, dat how can we move furhter as the main thing is dat which happen wid me too i dont get how to move sometimes :P

Answer 27

Lol, it takes time to form it out systematically. otherwise jab main khud karta hoon toh dhada-dhad ye lagaya woh kiya and lo! the answer ;)

Answer 28

xactly in my cohcing mere teacher jb bhi koi wn dete h and wen he see my notebook not in allen duri coching m pehle y hi sochte h kam kaha kiya h :P

Answer 29

haha lol.

Answer 30

ni sach m :P meri dusri coching k teacher pta h har step likhte h or m shortcut marti rhti hu wek line m hi sara kata piti :P :P