X is always the independent variable
Center of the solar system
First calculate the initial moles of HCl.
HCl moles i = (1.45 moles / L) * 0.5 L = 0.725 moles HCl
Then calculate how much HCl is consumed by stoichiometry:
HCl moles consumed = (12.7 g Zn / 65.38 g / mol) * (2
moles HCl / 1 mole Zn) = 0.388 moles
So HCl moles left is:
HCl moles f = 0.725 – 0.388 = 0.3365 moles
For every 1 mole HCl there is 1 mole H, therefore:
H moles final = 0.3365 moles
So final concentration of H ions is:
<span>Concentration H = 0.3365 moles / 0.5 L = 0.673 M</span>
As you move around there is a change in: electronegativies, ionisation energies, atomic radius etc. different amounts of these properties are going to effect how the element acts
Remember this:
atomic mass= atomic number + number of neutrons
The atomic number (same thing as number of protons) in this case is 15. The atomic mass is 31.
So, we subtract 15 from 31 to find the number of neutrons.
31-15=16
16 neutrons!!!