Delta E = Ef - Ei
E = energy , h = plank constant , v = frequency
h= 6.626 * 10 ^-34 j*s , T = 10 ^ 12 , v = 74 * 10 ^12 Hz , Hz = s^-1
E = ( 6.626 * 10^ -34 j*s) ( 74 * 10 ^ 12 s^ -1 ) = 4.90 * 10 ^ -20 J
Delta E = Ef - Ei
-4.90 * 10 ^ -20 J = -2.18 * 10 ^ -18J ( 1/4 ^2 - 1/x ^2)
0.0225 = 0.0625 - ( 1/x ^ 2)
0.225 - 0.0625 = - 1/ x ^ 2
- 0.0400 = - 1/x ^2 = -1 / - 0.0400 = x^2
25 = x^2
x = 5
Answer:
Weight is the measure of the force of gravity on an object. The mass of an object will never change, but the weight of an item can change based on its location. For example, you may weigh 100 pounds on Earth, but in outer space you would be weightless.
Explanation:
I can't see the options but I hope this helps!
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:
Electrolytes are defined as those compounds which dissolve in a solvent such as water to produce a solution which conducts electric current easily.
Explanation:
Electrolytes are chemical compounds that dissolve in a solvent such as water and dissociate into ions (cations and anions) which helps to conduct electric current. They can be solids, liquids, or solutions and examples include all ionic compounds such as sodium chloride, calcium chloride, etc.
When electrodes are placed in a solution containing an electrolyte, the ions produced in the solution move from one electrode to the other. The negatively charged ions called anions are attracted to the positive electrode and the positively charged ions called cations are attracted to the negative electrode. This movement of ions generates an electric current. Electrolytes are also needed for the various electrochemical processes in living things and the main ions in these electrolytes are sodium (Na+), calcium (Ca2+), potassium (K+), magnesium (Mg2+), chloride (Cl-), etc.
