You visited us 1 times! Enjoying our articles? Unlock Full Access!

Secondary Cells

A lead storag...

Question

A lead storage cell is discharged which causes the $H_{2} S O_{4}$ electrolyte from a concentration of $34.6$ % by mass (density 1.261 g $m l^{- 1}$ at $28^{o} C$ ) to one of $27$ % by mass. The original volume of electrolyte is one litre. How many Faraday have left the anode of battery? Note the water is produced by the cell reaction and $H_{2} S O_{4}$ is used up. Overall reaction is :
$P b (s) + P b O_{2} + 2 H_{2} S O_{4} (l) \to 2 P b S O_{4} (s) + 2 H_{2} O$

2.5 F

No worries! We‘ve got your back. Try BYJU‘S free classes today!

0.22 F

No worries! We‘ve got your back. Try BYJU‘S free classes today!

1.1 F

No worries! We‘ve got your back. Try BYJU‘S free classes today!

0.97 F

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

Open in App

Solution

The correct option is D $0.97 F$
Mass of $H_{2} S O_{4} = V \times d = 1261 g m$
Mass of $H_{2} S O_{4}$ used $= (34.6 - 27) = 7.6 % = 0.076 \times 1261 = 95.83 g m$

Moles of $H_{2} S O_{4}$ used up $= \frac{95.83}{98} = 0.97 m o l e s$

Faradays of electricity used $= \frac{0.97}{1} = 0.97 F$

Suggest Corrections

Similar questions

During discharging of lead-storage acid battery following reaction takes place:

P b (s) + P b O_{2} (s) + 2 H_{2} S O_{4} \to 2 P b S O_{4} (s) + 2 H_{2} O

If 2.5 amp of current is drawn for 965 minutes, $H_{2} S O_{4}$ consumed is:

H_{2} S O_{4}

1.294

1.139

. S u l p h u r i c a c i d o f d e n s i t y

i s

b y w e i g h t a n d t h a t o f d e n s i t y

i s

b y w e i g h t . T h e b a t t e r y h o l d

o f t h e a c i d a n d v o l u m e r e m a i n s p r a c t i c a l l y c o n s t a n t d u r i n g d i s c h a r g e . C a l c u l a t e a m p e r e - h o u r o f w h i c h t h e b a t t e r y m u s t h a v e b e e n u s e d . T h e c h a r g i n g a n d d i s c h a r g i n g r e a c t i o n s a r e :

(c h a r g i n g)

P b (s) + P b O_{2} + 2 H_{2} S O_{4} (a q) \to 2 P b S O_{4} (s) + 2 H_{2} O

1.25 A

H_{2} S O_{4}

m l^{- 1}

m l^{- 1}

m l^{- 1}

P b + S O_{4}^{2 -} \to P b S O_{4} + 2 e ⟹

P b O_{2} + 4 H^{+} + S O_{4}^{2 -} + 2 e \to P b S O_{4} + 2 H_{2} O ⟹

g m L^{- 1}

H_{2} S O_{4}

1.294 g m L^{- 1}

1.139 g m L^{- 1}

P b + S O_{4}^{2 -} \to P b S O_{4} + 2 e^{-}

P b O_{2} + 4 H^{+} + S O_{4}^{2 -} + 2 e^{-} \to P b S O_{4} + 2 H_{2} O

Join BYJU'S Learning Program