What does an upward arrow indicate in a chemical reaction?
Answer and explanation
Correct answer: Evolution of a gas
In a chemical equation, an upward arrow shows that a gas is evolved during the reaction. For example, hydrogen gas is produced when zinc reacts with a dilute acid. A downward arrow is generally used for the formation of a precipitate, so option B is not correct. Exam tip: remember—upward arrow for gas, downward arrow for precipitate.
Frequently asked questions
What is the correct answer to this question?
Evolution of a gas
Why is this the correct answer?
In a chemical equation, an upward arrow shows that a gas is evolved during the reaction. For example, hydrogen gas is produced when zinc reacts with a dilute acid. A downward arrow is generally used for the formation of a precipitate, so option B is not correct. Exam tip: remember—upward arrow for gas, downward arrow for precipitate.
Which subject and chapter does this question cover?
This is a Class 10 Science question. Chapter: Chemical Substances – Nature and Behaviour. Topic: Chemical Reactions and Equations.
