Home
Class 12
CHEMISTRY
30 mL of 0.13 M NiSO(4) is electrolysed ...

`30 mL` of `0.13 M NiSO_(4)` is electrolysed using a current of `360` milliamperes for `35.3` minutes. The mass of the metal that would have been plated out if current efficiency is only `60%` (`Ni = 58.7 u`) is

A

`0.9131 g`

B

`0.3911 g`

C

`0.1391 g`

D

`0.2474 g`

Text Solution

Verified by Experts

The correct Answer is:
C
The current efficiency is define as the ration of the amount of the converted substance to the amount of the substance that would react if the whole current is used in a given reaction.
Thus
`%` current efficiently
`= ("Actuall mass of Ni deposited")/("Expected mass of Ni deposited") xx 100%`
Calculate the mass of `Ni` that should be deposited :
Charge in coulombs = current in amperes `xx` time in seconds
`= (0.36 A)(35.3 "minutes")(60 "seconds/min")`
`= 762.48 C`
No. of faraday `= (762.48 C)/(96500 C//F)`
`= 0.0079 F`
Since `1 F` (1 mole of electric charge) produces `1` equivalent of the substance, no of equivalents of `Ni` that should be deposited for `100%` current efficiency is equal to no. of faradays. Thus, mass of `Ni` deposited for `100%` current efficiency will be
(no of equivalents)(`gm` equivalent mass)
`= (0.0079 eq.)(58.7//2 g eq.^(-1))[Ni^(2+)+2e^(-)rarrNi]`
But the current effciency is `60%` only. Thus
Actual mass of `Ni` deposited `= 0.2318 xx (60)/(100)`
`= 0.1391 g`
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • ELECTROCHEMISTRY

    R SHARMA|Exercise Follow-up Test 9|11 Videos

  • ELECTROCHEMISTRY

    R SHARMA|Exercise Follow-up Test 10|3 Videos

  • ELECTROCHEMISTRY

    R SHARMA|Exercise Follow-up Test 7|12 Videos

  • COORDINATION COMPOUNDS

    R SHARMA|Exercise Archives|56 Videos

  • GENERAL PRINCIPALS AND ISOLATION OF ELEMENTS

    R SHARMA|Exercise Arechives|16 Videos

Similar Questions

Explore conceptually related problems

A solution of Ni(NO_(3))_(2) is electrolysed between platinum electrodes using a current of 5.0 amp for 20 minutes. What mass of the nickel will be deposited at the cathode ? (Ni = 58.7 u)

A solution of Ni(NO_3)_2 is electrolysed between platinum electrodes using a current of 0.5 ampere for 20 minutes. What mass of Ni is deposited at the cathode ?

A solution of Ni(NO_(3))_(2) is electrolysed between platinum electrodes using a current of 5.0 ampere for 20 minutes. What mass of nickel will be deposited at the cathode? (At. Mass of Ni=58.7)

40 mL of 0.125 M of NiSO_(4) solution is electrolysed by a current of 0.05 amp for 40 minutes. (i) Write the equation for the reactions occurring at each electrode. (ii) How many coulombs of electricity passed through the solution ? (iii) How many grams of the product deposited on the cathode ? (iv) How long will the same current have to pass through the solution to remove completely the metal ions from the solution ? (v) At the end of electrolysis how many grams of the product would appear at the anode ?

500 ml CuSO_(4) solution was electrolysed using a current of 2 amp (efficiency =75%) for 60 min calculate the pH of solution at the end of electrolysis (Assume initial pH=7)

A test for complete romovel of Cu^(2+) ions form a solution of Cu_((aq.))^(2+) is to add NH_(3(aq.)) . A buke colour signifies the fomaltionn of complex [Cu(NH_(3))_(4)]^(2+) having K_(f) = 1.1 xx 10^(13) and thus confirms the presence of Cu^(2+) in solution. 250 mL of 0.1 M CuSO_(4(aq.)) is electrolysed by passing a current of 3.512 ampere for 1368 second. After passage of this passage of this charge sufficient quantity of NH_(3(aq.)) is added to electrolysed solution maintaining [NH_(3)] = 0.10 M . If [Cu(NH_(3))_(4)]^(2+) is detectable up to its concentration as low as 1 xx 10^(-5) , would a blue colour be shown by the electrolysed solution on addition of NH_(3) .

A test for complete removal of Cu^(2+) ions from a solution of Cu^(2+) (aq) is to add NH_3 (aq). A blue colour signifies the formation of complex [Cu(NH_3)_4]^(2+) having K_f = 1.1 xx 10^13 and thus confirms the presence of Cu^(2+) in solution. 250 mL of 0.1 M CuSO_4 (aq.) is electrolysed by passing a current of 3.512 ampere for 1368 second. After passage of this charge sufficient quantity of NH_3 (aq) is added to electrolysed solution maintianing [NH_3] = 0.10 M. If [Cu(NH_3)_4]^(2+) is detectable upto its concentration as low as 1 xx 10^(–5) , would a blue colour be shown by the electrolysed solution on addition of NH_3 ?

50 mL of 0.1 M CuSO_(4) solution is electrolysed using Pt electrodes with a current of 0.965 ampere for a period of 1 minute. Assuming that volume of solution does not change during electrolysis, calculate [Cu^(2+)], [H^(+)] and [SO_(4)^(2-)] after electrolusis. What will be the concentration of each species if current is passed using Cu electrodes ?

50 mL of 0.1 M CuSO_4 solution is electrolysed using Pt electrodes with a current of 0.965 ampere for a period of 1 minute. Assuming that volume of solution does not change during electrolysis, calculate [Cu^(2+)]. [H^+] and [SO_4^(2–)] after electrolysis. What will be the concentration of each species if current is passed using Cu electrodes ?

A solution of M(NO_(3))_(2) was electrolysed by passing a current of 2.5 A and 3.06 g of the metal was deposited in 35 minutes. Determine the molar mass of the metal.

Home
Profile