Thank you for posting your math problem here. To convert 3.9x10^5mg to dg the answer is <span>3.9 x 10^3 dg. Below is the solution:
Solution:
</span><span>1mg=0.01dg
</span><span> dg= 3.9 X 10^5mg
</span>dg = <span>(3.9 X 10^5) x 0.01
dg = </span><span>3.9 x 10^3 </span>
Answer:
D 1 and 3 only I am not sure
Explanation:
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
Covalent bonding!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
