Boiling water results in no chemical change. If water is just heated to its boiling temperature then there is a physical change.
Answer:
Explanation: The flame test is used to visually determine the identity of an unknown metal or metalloid ion based on the characteristic color.
Hope this helps
Answer:
I dont know the answer for that question it's hard question isn't it
Answer:
pKa = 3.675
Explanation:
∴ <em>C</em> X-281 = 0.079 M
∴ pH = 2.40
let X-281 a weak acid ( HA ):
∴ HA ↔ H+ + A-
⇒ Ka = [H+] * [A-] / [HA]
mass balance:
⇒<em> C</em> HA = 0.079 M = [HA] + [A-]
⇒ [HA] = 0.079 - [A-]
charge balance:
⇒ [H+] = [A-] + [OH-]... [OH-] is negligible; it comes from to water
⇒ [H+] = [A-]
∴ pH = - log [H+] = 2.40
⇒ [H+] = 3.981 E-3 M
replacing in Ka:
⇒ Ka = [H+]² / ( 0.079 - [H+] )
⇒ Ka = ( 3.981 E-3 )² / ( 0.079 - 3.981 E-3 )
⇒ Ka = 2.113 E-4
⇒ pKa = - Log ( 2.113 E-4 )
⇒ pKa = 3.675
Answer:
9.7 x 10⁻⁴
Explanation:
HA ⇄ H⁺ + A⁻
C(eq) 0.0174 10⁻²·³⁹ 10⁻²·³⁹
=0.0041M =0.0041M
Ka = [H⁺][A⁻]/[HA] = (0.0014)²/(0.0174) = 9.7 x 10⁻⁴
