Hey there!
MgCl₂
Find molar mass of magnesium chloride.
Mg: 1 x 24.305
Cl: 2 x 35.453
--------------------
95.211 grams
One mole of magnesium chloride has a mass of 95.211 grams.
We have 2.40 moles.
2.40 x 95.211 = 228.5
To 3 sig figs this is 229.
The mass of 2.40 moles of magnesium chloride is 229 grams.
Hope this helps!
Answer:
number of valence electrons
Explanation:
All of the elements in group 17, also known as group 7A, have 7 valence electrons.
No two elements have the same atomic number nor atomic mass in elemental form.
Halogens may have any number of isotopes.
PH to maximize the dissociation of acetic acid so as to push back the amount of acetate dissociating from the mystery compound.
<span>
Ksp = [X+][C2H3O2-] = 9.5*10^-6 </span>
<span>Substituting in the desired value for [X+] </span>
<span>9.5*10^-6 = (5.0*10^-3)x </span>
x, or acetate concentration, is .0019
<span>Now, we calculate the Ka of acetic acid: </span>
<span>pKa = -logKa </span>
<span>4.76 = -logKa </span>
<span>Ka = 1.738*10^-5 </span>
<span>We want the concentration of acetate to be .0019, so we plug that into our acid dissociation constant expression: </span>
<span>Ka = [H+][C2H3O2-]/[HC2H3O2] </span>
1.738*10^-5<span> = [H+](.0019)/1</span>
<span>[H+] = .00915</span>
<span>pH = -log[H+] </span>
<span>pH = -log(.00915) </span>
pH = 2.04
