Your limiting is CuCI2 and the excess is KI (from what i’ve heard from my tc to find it just use the moles or look at the grams)Do you want me to do the qn and give u the ans or?
Explanation:You have more grams of KI than CuCI2
irl example : I need 200g of flour to bake 1 muffin and 100g of butter.But I have 300g of butter and only 200g of flour.This means I can only bake up to 1 muffin since I got excess grams of butter.But to use up all my 300g of butter I need 400g more of flour.Making my butter the excess while my flour the limiting since I have less of it and it also determines how much muffin would I get at the end of the bake.
im sorry if that example sounds clowny T-T
Answer:- The natural abundance of
is 0.478 or 47.8% and
is 0.522 or 52.2% .
Solution:- Average atomic mass of an element is calculated from the atomic masses of it's isotopes and their abundances using the formula:
Average atomic mass = mass of first isotope(abundance) + mass of second isotope(abundance)
We have been given with atomic masses for
and
as 150.919860 and 152.921243 amu, respectively. Average atomic mass of Eu is 151.964 amu.
Sum of natural abundances of isotopes of an element is always 1. If we assume the abundance of
as n then the abundance of
would be 1-n .
Let's plug in the values in the formula:

151.964=150.919860n+152.921243-152.921243n
on keeping similar terms on same side:


negative sign is on both sides so it is canceled:



The abundance of
is 0.478 which is 47.8%.
The abundance of
is = 
= 0.522 which is 52.2%
Hence, the natural abundance of
is 0.478 or 47.8% and
is 0.522 or 52.2% .
The balanced chemical reaction is:
<span>N2 + 3H2 = 2NH3 </span>
We are given the amount of H2 being reacted. This will be our starting point.
26.3 g H2 (1 mol H2 / 2.02 g H2) 2 mol
O2/3 mol H2) ( 17.04 g NH3 / 1mol NH3) = 147.90 g O2
Percent yield = actual yield / theoretical
yield x 100
Percent yield = 79.0 g / 147.90 g x 100
Percent yield = 53.4%
<span>The </span>standard enthalpy of formation<span> <span>is defined as the change in </span></span>enthalpy<span> <span>when one mole of a substance in the </span></span>standard<span> <span>state (1 atm of pressure and temperature of 298.15
K) is </span></span>formed<span> <span>from its
pure elements under the same conditions.</span></span>