---
title: "Normal hydrogen electrode"
subject: "Engineering Chemistry"
chapter: 1
key: "semester_2/engineering_chemistry:normal-hydrogen-electrode"
source: https://www.bctengineer.com/q/semester_2/engineering_chemistry/normal-hydrogen-electrode
site: BCT Engineering
---

# Normal hydrogen electrode

Engineering Chemistry · Chapter 1: Electro-chemistry and Buffer

- Asked in: 2070 Bhadra, 1 marks
- Video: [Standard hydrogen electrode | SHE | Normal hydrogen electrode (NHE) | Electrochemistry](https://www.youtube.com/watch?v=jZ-5zBfWyNM) — MJD Chemistry
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_2/engineering_chemistry/normal-hydrogen-electrode
- Whole chapter: https://www.bctengineer.com/md/semester_2/engineering_chemistry/chapter-1

## Question

What is normal hydrogen electrode?

## Short answer

The normal hydrogen electrode is a reference electrode with platinum black in 1 M H+, H2 gas at 1 atm and 25°C, its potential arbitrarily set to zero. Notation: Pt, H2 (1 atm) | H+ (1 M).

## Answer

The **normal (standard) hydrogen electrode** is a reference electrode made of a platinum foil coated with platinum black, dipped in a solution of 1 N (1 M) H⁺ ions, with pure hydrogen gas at 1 atm bubbled over it at 25°C. Its potential is arbitrarily taken as zero. Notation: Pt, H₂ (1 atm) | H⁺ (1 M).

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. The normal hydrogen electrode consists of:
   A. Zn in 1 N H2SO4
   B. Cu in H2 at 2 atm
   C. Pt in water with O2
   D. Pt black foil in 1 N H+ with H2 at 1 atm, 25°C
   Answer: D. It is a Pt foil coated with Pt black in 1 N (1 M) H+ with pure H2 at 1 atm and 25°C. (Key point: Composition)

2. Its potential is taken as:
   A. +1.00 V
   B. -0.34 V
   C. +0.76 V
   D. Zero (arbitrarily)
   Answer: D. It is a reference electrode with arbitrary potential 0 V. (Key point: Assigned potential)

3. Notation of the electrode is:
   A. H2 | Zn2+
   B. Pt | OH-
   C. Cu | H+
   D. Pt, H2 (1 atm) | H+ (1 M)
   Answer: D. Pt, H2 (1 atm) | H+ (1 M). (Key point: Notation)

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