Question

15. A metal of unknown atomic mass exists as a trivalent ion. When electrolysed in solution using a current of 367mA for 186 min, 0.736g of the metal was deposited on the cathode. Calculate the atomic mass of metal

Answer 1

@thushananth01

Answer 2

U have been given the current and time, what can you find from that

Answer 3

coulombs

Answer 4

0.367 x 11160 =4095.72 C

Answer 5

is that correct?

Answer 6

I coverted the mins into seconds as time is measured in minutes. I converted milliAmps to Amps due to Current been measured in Amps

Answer 7

yes thats right..Now you can make an equation

\[M^{3+}_{(aq)} + 3e^{-} = M _{(s)}\]

Answer 8

u know that 1 mol of electron is equal to 96500C right

Answer 9

yes

Answer 10

so what do i do next??

Answer 11

Yes
3 mol of electron gives 1 mol of Metal which means
3 * 96500C = 1 Mol of metal
so
4095.2C gives how mch mole of metal

Answer 12

ratio :D

Answer 13

do you divide 96500C by 4095.2C

Answer 14

Could you show me how to find the ration please?

Answer 15

ratio*

Answer 16

0.014

Answer 17

yes
u know
Mole = mass / Ar
u know mole, mass! There you go :)

Answer 18

so thats the answer = 0.014?

Answer 19

no ur supposed to find Ar

Answer 20

use n = mass/Ar where n=no of moles

Answer 21

52.57 g/mol

Answer 22

yes thats right

Answer 23

so thats the answer

Answer 24

yup

Answer 25

Thanks for your help :)

Answer 26

no prbs :)