Problem 29 - Chemistry: The Central Science

Question

Describe two characteristics of hydrogen that are favorable for its use as a general energy source in vehicles.

Step-by-Step Solution

Answer

Hydrogen has two favorable characteristics for use as a general energy source in vehicles: 1) High Energy Content - Hydrogen has a high energy density by weight, which is about 2.75 times higher than gasoline, allowing for longer driving ranges before refueling; 2) Environmentally Friendly - Hydrogen fuel cells produce only water and heat as by-products, resulting in zero harmful emissions and contributing to reduced air pollution and greenhouse gas emissions.

Step 1: Characteristic 1: High Energy Content

Hydrogen has a high energy content, which makes it an attractive energy source for vehicles. Its energy density by weight is about 2.75 times higher than that of gasoline. This means that a smaller amount of hydrogen can deliver the same amount of energy as a larger volume of other fuels. This high energy content also means that vehicles powered by hydrogen can potentially achieve longer driving ranges before needing to refuel.

Step 2: Characteristic 2: Environmentally Friendly

Hydrogen, when used as a fuel in fuel cells, only produces water and heat as by-products. This means that vehicles running on hydrogen fuel cells have zero harmful emissions, such as carbon dioxide, nitrogen oxides, and particulate matter, which are common in vehicles that run on fossil fuels. Therefore, hydrogen-powered vehicles help to reduce air pollution and greenhouse gas emissions, making hydrogen a more environmentally friendly energy source for vehicles.