When the Pka for formic acid = 3.77
and Pka = -㏒ Ka
3.77 = -㏒ Ka
∴Ka = 1.7x10^-4
when Ka = [H+][HCOO-}/[HCOOH]
when we have Ka = 1.7x10^-4 &[HCOOH] = 0.21 m
so by substitution: by using ICE table value
1.7x10^-4 = X*X / (0.21-X)
(1.7x10^-4)*(0.21-X) = X^2 by solving this equation for X
∴X = 0.0059
∴[H+] = 0.0059
∴PH= -㏒ [H+]
= -㏒ 0.0059
= 2.23
Answer:
1.
A= <u>sum</u><u>(</u><u>mass</u><u>*</u><u>percent</u><u> </u><u>abundance</u><u>)</u>
M 100
=(23.985*78.70)+(24.946*10.13)+(25.983*11.17)/100
= 24.3
2. The element is Magnesium.
3. 2412Mg,2512Mg and 2612Mg
Answer:
2Fe + 3H2SO4 + Fe2(SO4)3+ 3H2
Explanation:
1. Fe (SO4) 3 is an incorrectly written formula because iron is trivalent as we can see by this three ahead of SO4. SO4 is divalent always.
2. since (SO4) is 3, this three shows us that there must be 3 in the reactants as well.
so now there is 3H2SO4
3. Since we have added 3 to one hydrogen we must add another. So now it's 3H2
4. and finally iron. In Fe2 (SO4) 3 we see this 2 in front of Fe which means it goes 2Fe.
The salt causes the water to freeze at a lower temperature. When a solute, aka salt, is introduced to the system, the freezing point is lowered. This makes the water freeze at a lower temperature.
