X in ICE table

Moderators: Chem_Mod, Chem_Admin

Steven Chau 1B
Posts: 21
Joined: Fri Sep 29, 2017 7:07 am

X in ICE table

Postby Steven Chau 1B » Sat Dec 09, 2017 8:09 pm

How do we determine if we need to add or subtract x from the reactant?

Nishma Chakraborty 1J
Posts: 51
Joined: Fri Sep 29, 2017 7:04 am

Re: X in ICE table

Postby Nishma Chakraborty 1J » Sat Dec 09, 2017 8:12 pm

Hey!

It depends on the direction of the reaction (which you can determine from the equilibrium constant). For instance, if Kc is 2*10^-5, there are more reactants than products, so the system will shift towards the products in order to balance out/reach equilibrium. In that case, you would subtract x from the reactant(s), and add x to the product(s).

Hope this helps :)

Kyra Dingle 1B
Posts: 55
Joined: Fri Sep 29, 2017 7:04 am

Re: X in ICE table

Postby Kyra Dingle 1B » Sat Dec 09, 2017 8:13 pm

One way to determine is through what the problem gives you. If only the amount of the initial reactant is given, then the initial concentration of the products would be 0. This then means that the reactants will be consumed to make products until the reaction reaches equilibrium. Since the reactants are being consumed, you would need to subtract x from the reactants in this situation.

Angel Gomez 1K
Posts: 36
Joined: Fri Sep 29, 2017 7:04 am

Re: X in ICE table

Postby Angel Gomez 1K » Sat Dec 09, 2017 8:43 pm

If you were given the concentrations to both products and reactants, you would first need to find Q, which is given by [P]/[R]. Given a value for Kc, you would need to compare Q to Kc and see if it is greater than or less than. If Q is greater, then that means that the reaction would shift toward the reactant side, and you'd subtract x from the product side. If Q was lesser, then that means the reaction would shift toward the product side, and you'd subtract x from the reactant side.


Return to “Calculating pH or pOH for Strong & Weak Acids & Bases”

Who is online

Users browsing this forum: No registered users and 1 guest