Question

calculate the mass of hydrogen evolved by passing a current of 0.5A for 40 min through acidulated water

Answer 1

Quantity of electricity (C) = Current (I) x Time (s)
                                           = 0.5 x 40 x 60 (Time in seconds)
                                           = 1200 C
96500 C ≡ 1 Mole of electrons
∴ 1200 C ≡ (1200 x 1)/96500
                 = 0.01244 moles of electrons

1 Mole of hydrogen atoms is liberated by 1 mole of electrons
∴ The No. of moles of electrons liberated = 0.01244 moles
H = 1
1 mole of hydrogen atoms has a mass of 1 g
∴ Mass = Molar mass x No. of mole
Mass of hydrogen = 1 x 0.01244 = 0.01244 g

Answer 2

Answer:

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