## Back and Fourth Arrows

Danieljm1B
Posts: 30
Joined: Mon Feb 25, 2019 12:15 am

### Back and Fourth Arrows

When are doubled headed arrows used in chemical formulas, or in other words, arrows pointing in both directions? Is it when a reaction is reversible? In that case when is it acceptable to use these arrows against using arrows just pointing one way?

Kevin To 1B
Posts: 32
Joined: Sat Feb 02, 2019 12:15 am

### Re: Back and Fourth Arrows

Such arrows are to represent a certain chemical equation that can go forward or reverse. Generally, these arrows appear in chemical equations that deal with equilibrium, including acid-base equilibria. The direction of the reaction would depend on the quantity of reactants vs products, as determined by Le Châtelier’s Principle.

Haorui Li 1A
Posts: 30
Joined: Mon Jun 17, 2019 7:23 am

### Re: Back and Fourth Arrows

Two-way double half arrows represent a reaction that can go either forward or reverse. Whether the reaction shifts or not depends on Le Chatlier's principle. In the lecture, strong acids used double arrows but weak acids used single arrows.

Yen Ho Chou 1D
Posts: 28
Joined: Wed Feb 27, 2019 12:16 am

### Re: Back and Fourth Arrows

When there are two arrows, the reaction is reversible

Grecia Velasco 4D
Posts: 56
Joined: Thu Jul 11, 2019 12:17 am

### Re: Back and Fourth Arrows

Danieljm1B wrote:When are doubled headed arrows used in chemical formulas, or in other words, arrows pointing in both directions? Is it when a reaction is reversible? In that case when is it acceptable to use these arrows against using arrows just pointing one way?

Two arrows means reaction is reversible.

Alex Hitti 3E
Posts: 51
Joined: Sat Aug 17, 2019 12:17 am

### Re: Back and Fourth Arrows

Double headed arrows is the symbol that implies that the reaction is reversible. If an arrow is pointing only one way then that implies that the reaction is nonreversible.

KaleenaJezycki_1I
Posts: 127
Joined: Sat Aug 17, 2019 12:18 am
Been upvoted: 2 times

### Re: Back and Fourth Arrows

Danieljm1B wrote:When are doubled headed arrows used in chemical formulas, or in other words, arrows pointing in both directions? Is it when a reaction is reversible? In that case when is it acceptable to use these arrows against using arrows just pointing one way?

Yes, that is correct. If the arrows point both ways then the reaction is reversible. This will not be something to stress right now, it will probably be mentioned when we begin to talk about acids and bases and equilibrium.