In car safety airbag systems, which chemical compound is commonly used inside the airbag to rapidly produce gas on impact?

Introduction / Context:
Modern cars are equipped with airbag systems designed to protect passengers during collisions. These airbags must inflate within fractions of a second when an impact is detected. To achieve this, a chemical compound inside the airbag rapidly decomposes to produce a large volume of gas. General science questions often ask which compound is used in airbags because it connects basic chemistry with an everyday safety device.

Given Data / Assumptions:

• The question asks which compound is used in car airbags to generate gas.
• Options include sodium bicarbonate, sodium azide, sodium nitrite, sodium peroxide, and None of the above.
• We assume traditional gas generating airbag designs that rely on rapid decomposition of a solid chemical.

Concept / Approach:
Sodium azide (NaN3) has historically been used in many airbag systems. When triggered by a sensor in a collision, an igniter heats the sodium azide, causing it to decompose quickly into sodium metal and nitrogen gas. The large volume of nitrogen fills the airbag almost instantly. While newer systems may use alternative compounds for safety and environmental reasons, sodium azide is the standard answer in exam oriented general science questions on airbags.

Step-by-Step Solution:
Step 1: Recognise that the key requirement for an airbag is very rapid gas generation. Step 2: Recall that sodium azide decomposes explosively when heated, releasing nitrogen gas. Step 3: The reaction produces mostly nitrogen, which is inert and safe to use as a filling gas in the bag. Step 4: Compare other compounds: sodium bicarbonate is common in baking powder and fire extinguishers, not in airbags; sodium nitrite and peroxide have different uses and reaction behaviours. Step 5: Conclude that sodium azide is the compound associated with traditional airbag systems.

Verification / Alternative check:
Standard general science references and safety engineering texts describe early and widely used airbags as sodium azide based. The rapid decomposition of NaN3 to N2 gas is well documented. Although environmental concerns have led to research on azide free systems, exam questions continue to refer to sodium azide as the canonical example. None of the other sodium salts listed are routinely cited as the primary gas generating compound in airbags, supporting this conclusion.

Why Other Options Are Wrong:
Sodium bicarbonate: Used in baking powders and some fire extinguishers, but not as the main gas generator in airbags. Sodium nitrite: Has roles in food preservation and industry but is not standard in airbag inflation chemistry. Sodium peroxide: A strong oxidising agent, dangerous for rapid oxygen release, not used in nitrogen based airbag systems. None of the above: Incorrect because sodium azide is correctly included and is the expected answer.

Common Pitfalls:
Some students may confuse sodium azide with more familiar compounds like sodium bicarbonate simply because they have seen the latter in household contexts. Others might overthink and worry about modern replacements for azide, leading them to choose None of the above. For exam purposes, however, sodium azide remains the standard textbook answer for the compound used in car airbags.

Final Answer:
Car safety airbags traditionally use sodium azide to generate nitrogen gas rapidly on impact.