Molecular hydrogen is produced as a byproduct in the industrial production of NaOH by electrolysis of aq \(NaCl\) solution
\(NaCl → Na^+ + Cl^–\)
\(H_2O ⇌ H^+ + OH^-\)
Cathode : \(2H_2O + 2e → H_2 + 2OH^–\)
Anode : \(2Cl^– → Cl_2 +2e\)
\(NaOH\) is crystallised from the remaining part of electrolyte.
The portion of the line \( 4x + 5y = 20 \) in the first quadrant is trisected by the lines \( L_1 \) and \( L_2 \) passing through the origin. The tangent of an angle between the lines \( L_1 \) and \( L_2 \) is: