## Determining the state of matter

Ashley Wang 4G
Posts: 103
Joined: Wed Sep 11, 2019 12:16 am

### Determining the state of matter

I was wondering if there are any ways to determine what state (s, l, g, aq) a compound is in? Specifically, when a word problem describes a reaction and we are expected to write the chemical equation, how do I determine what state each compound is in if it is not stated in the question?

Should I determine the state of the compound based on the properties of its constituent elements, and the type of bonding that exists? Does the knowledge come with experience as I familiarize myself with common compounds?

Thank you!

rabiasumar2E
Posts: 108
Joined: Thu Jul 11, 2019 12:15 am

### Re: Determining the state of matter

I don't believe it's always possible to be able to determine the states of matter if they aren't given to you in the problem. If the problem states that all elements or compounds are at "normal temperature and pressure" you could maybe infer what the state of matter is from what you know about the elements.

Cassidy Kohlenberger 3D
Posts: 51
Joined: Wed Sep 18, 2019 12:19 am

### Re: Determining the state of matter

I think it just comes with familiarizing yourself with the compounds, but for some of them you can assume like H20 being liquid or if the problem tells you H20 vapor, then a gas. Diatomic elements like nitrogen, oxygen, hydrogen, etc. will be gases at room temperature. Usually compounds with oxide (OH) are aqueous.

Matthew ILG 1L
Posts: 112
Joined: Sat Aug 17, 2019 12:15 am

### Re: Determining the state of matter

Often times when there are two of a molecule in a balanced equation, such as 0subscript2 or Hsubscript2, it is a gas.

sbottomley3a
Posts: 50
Joined: Wed Sep 18, 2019 12:19 am

### Re: Determining the state of matter

I don't think we are required to know unless it is specifically stated or indicated in the problem given. The question might give the compound's state explicitly, or it may tell us that it has a very high boiling temp, so that we know it may be liquid at room temperature. Some states of compounds we will remember as we familiarize ourselves with them, but it won't always be clear. For instance, H2O can indicate ice, water vapor, or liquid water.