2CuI (s) + I₂ (aq) → 2 Cu⁺² (aq) + 4 I⁻ (aq)
When writing an equilibrium expression, we use the following values:
A (aq) + 3B (aq) → 2C (aq) + 2D (aq)
The numbers were arbitrary molar equivalents and the uppercase letters are the molecules in the reaction. The species used in the equilibrium expression but all be in the same state, e.g., solid, liquid, aqeuous.
Kc = [C]²[D]² / [A][B]³
We write the formula by taking the concentration of the products, each to the power of their molar equivalent, and multiply them together. We then divide the products by the concentration of the reactants, also to the power of their molar equivalent.
Going back to the initial equation given, we can now write a Kc expression.
Kc = [Cu⁺²]²[I⁻]⁴ / [I₂]
It should be noted that the CuI (s) in the reaction was left out of the Kc expression. Pure solids and liquids are left out of the expression and only the aqueous species are included. The reason being that, in this case, solid CuI does not affect the amount of reactant at equilibrium. Therefore, we just leave the concentration for [CuI] = 1, and remove it from the expression.
<span>Chromium(II) sulfate
this is an ionic compound of a metal and a polyatomic ion.
chromium is a metal that can form more than one type of cation. In this case, the polyatomic ion name is sulfate and it has 2 negative charges. Then Cr has to have 2 positive charges.
then write the name of the metal followed by the charge of the ion between parenthesis and in roman numbers followed by the name of the polyatomic ion.</span>
Well, in an atom, there are an equal number of protons and electrons so they cancel each other out.
We can change the state of motion of an object by changing its speed, its direction of motion, or both. Acceleration is the rate at which the velocity is changing. In physics, the term acceleration applies to decreases as well as increases in speed.