Welcome to the Sunday ChemistryViews Quiz!

We explore a chemistry topic in this fun and short quiz which will be out in irregular intervals on a Sunday morning. Test your knowledge and learn something new in just a few minutes.

Ready to dive in? Let’s go!

A spark you can barely feel, e.g., from a static discharge, has about the same amount of energy as is needed to ignite a mixture of hydrogen and air—true or false? 🤔

See answer

❌ False!

⚡ A spark you can barely feel, e.g., from a static discharge, already has about 50 times as much energy as needed to ignite a mixture of hydrogen and air (21 % oxygen).
⚡ A typical spark that you experience has over 1,000 times the energy required for ignition of the mixture.
🔥 At higher oxygen concentrations, the mixture is even more easily ignited.

Flammable Hydrogen-Air Mixtures

💥 Hydrogen-air mixtures are explosive in concentrations from 4 to 75 % hydrogen.
🌬️ Air contains 21 % oxygen.

With increasing oxygen concentration, the range becomes wider:
💥💥 In pure oxygen, the mixture is explosive from 4 to 94 % hydrogen. The required ignition energy is extremely low.
🚫 Smaller volumes of hydrogen-air mixtures do not mean the danger of ignition becomes smaller.

👉 Fun Fact – but not so funny, in fact

🛩️ Around 100 years ago, airships (Zeppelins) experienced a golden era, enabling wealthy passengers to cross the Atlantic in just two to three days.
🔥 One of the largest, the hydrogen-filled Hindenburg, tragically caught fire during its landing in Lakehurst, NJ, USA, on May 6, 1937, and crashed in flames within seconds. The disaster claimed the lives of 36 people.
⚡ Cause: The fire is attributed to the ignition of hydrogen, with high-energy, localized sparks now considered the most likely trigger [2].
🧵 The outer envelope of the Zeppelin was made of cotton and linen sheets, repeatedly coated with layers of Cellon—a fire-resistant mixture of cellulose acetate and camphor—for impregnation. To make the envelope reflective and prevent solar heating, aluminum flakes were also added to the mixture.
🪢 The envelope was attached to the Zeppelin’s aluminum framework with cords, while wooden spacers were inserted to prevent direct contact between the envelope and the frame.
🌩️ During the thunderstorm, the envelope acquired a positive electrostatic charge from the clouds, and when the anchor line—connected to the frame—touched the ground, it gave the framework a negative charge.
🔋 Because the wooden spacers electrically isolated the envelope from the frame, a growing electric field formed between them—essentially functioning like a capacitor.
📈 Wherever the envelope and frame came into closer proximity, these charge differences likely intensified, as if the Zeppelin were covered in hundreds of capacitors.
💥 Each of these capacitors generated its own sparks. Countless sparks likely occurred across the entire airship—some of them in areas where hydrogen was leaking.