I need the molecular formula of oxide of arsenic when it is in its gaseous state and I need to show how I got there.

Please help.

well, start of with the molecular formula of arsenic oxide. <biggest hint in the universe

 

then think about what a gas is.

thanks, but I must be really thick as I don't know how to express a gas in a formula.

okay, no problem. i'll walk you through it.

 

1. write down the molecular formula for arsenic oxide

2. add on '(g)'

3. move on.

 

the molecular formula of compunds doesn't change when they become a gas. the molecules just get further appart. so the molecular formula will be the same whether its a solid, liquid or gas.

 

the (g) part means 'gaseous' which means its that chemical in gas form.

(s) means solid

(l) means liquid

and (aq) means aqueous (a solution of that compund.)

 

hope this helps