Question

exam lesson name: energy conversions
exam number: 700697rr
exam guidelines
exam instructions
question 5 of 20 :
select the best answer for the question.

1. which substance is a liquid fuel used in rocket engines?

a. liquid nitrogen
b. potassium perchlorate
c. sodium nitrate
d. ammonia
mark for review (will be highlighted on the review page)
<< previous question
next question >>

Explanation:

To determine the liquid fuel for rocket engines, we analyze each option:

• Option A: Liquid nitrogen is a cryogenic fluid, not a fuel (it's an oxidizer or used for cooling, not energy release via combustion).
• Option B: Potassium perchlorate is a solid oxidizer, not a liquid fuel.
• Option C: Sodium nitrate is a solid compound, often used in fertilizers or as an oxidizer, not a liquid fuel.
• Option D: Ammonia ($\ce{NH3}$) is a liquid fuel used in some rocket engines, especially in combination with oxidizers like liquid oxygen. It can undergo combustion to release energy for propulsion.

Answer:

D. Ammonia