Answer:
Magnesium has 2 valence electrons.
Explanation:
The atomic number of magnesium is 12. This means that it has 12 protons and 12 electrons. The first electron shell can hold 2 electrons, the second can hold 8, so the third will have 2 electrons. The outermost shell of the atom has two electrons. Therefore, magnesium has 2 valence electrons.
To determine the pH of a solution which has 0.195 M hc2h3o2 and 0.125 M kc2h3o2, we use the ICE table and the acid dissociation constant of hc2h3o2 <span>to determine the concentration of the hydrogen ion present at equilibrium. We do as follows:
HC2H3OO = H+ + </span>C2H3OO-
KC2H3OO = K+ + C2H3OO-
Therefore, the only source of hydrogen ion would be the acid. We use the ICE table,
HC2H3OO H+ C2H3OO-
I 0.195 0 0.125
C -x +x +x
------------------------------------------------------------------
E 0.195-x x 0.125 + x
Ka = <span>1.8*10^-5 = (0.125 + x) (x) / 0.195 -x
x = 2.81x10^-5 M = [H+]
pH = - log [H+]
pH = -log 2.81x10^-5
pH = 4.55
Therefore, the pH of the resulting solution would be 4.55.</span>
No. of moles in 134g of Mg, n=134/24 =5.58 moles
No. of atoms = n* Avogadro number
= 5.58 X 6.022 X 10^23
=33.60 X 10^23 atoms
7.2 mol H × (1 mol H_2SO_4/2 mol H) = 3.6 mol H_2SO_4
