Answer:
Because the ideas about the models changed as more discoveries were made about the atom
Explanation:
I know because i took this test and made a 100% on it
hope I was helpful :)
Answer:
A
Explanation:
B) pollution doesn't affect water
C) Air pollution makes carbon dioxide
D) air pollution does not affect temperature
Answer: Mass of silver deposited at the cathode is 37.1g
Explanation: According to Faraday Law of Electrolysis, the mass of substance deposited at the electrode (cathode or anode) is directly proportional to quantity of electricity passed through the electrolyte
Faraday has found that to liberate one gm eq. of substance from an electrolyte, 96500C of electricity is required.
+e− ==> Ag(s)
Given that
Current (I) = 8.5A
Time (t) = 65 *60 = 3900s
Quantity of electricity passed = 8.5*3900 =33150C
Molar mass of Ag= 108g
96500C will liberate 108g
33150C will liberate Xg
Xg= (108*33150)/96500
=37.1g
Therefore the mass of Ag deposited at the cathode is 37.1g.
The molecules of the cold element are going to be closer together and still than the molecules of the hot element because the heat energy causes the molecules to be stimulated and to move.
<h3>How do molecules act at different temperatures?
</h3>
In the image you can see the behavior of the molecules when they are in different environments. On the right you see the cold molecules and on the left the hot molecules that are characterized by the following characteristics:
Cold molecules:
- Molecules together.
- Molecules with little movement.
Hot molecules:
- Separate molecules.
- Molecules with active movement.
A simple example to understand this behavior of molecules is water because:
- When water is frozen its molecules are almost static and close together.
- When the water is liquid and it is heated, the molecules move and that is why the water has bubbles, its molecules are separated.
Learn more about molecules in: brainly.com/question/19922822
Answer:
a) C6H5COOH + H2O ↔ H3O+ + C6H5COO-
b) [ H3O+ ] = 2.517 E-3 M
c) pH = 2.599
Explanation:
a) balanced equation:
C6H5COOH + H2O ↔ H3O+ + C6H5COO-
⇒ Ka = ( [ H3O+ ] * [ C6H5COO- ] ) / [ C6H5COOH ] = 6.5 E-5
mass balance:
0.10 m = [ C6H5COO- ] + [ C6H5COOH ].....(1)
charge balance:
[ H3O+ ] = [ C6H5COO- ] + [ OH- ] .......[ OH- ] : comes from water, it's not significant
⇒ [ H3O+ ] = [ C6H5COO- ] .........(2)
b) (2) in (1):
⇒ 0.10 M = [ H3O+ ] + [ C6H5COOH ]
⇒ [ C6H5COOH ] = 0.10 - [ H3O+ ]
⇒ Ka = [ H3O+ ]² / ( 0.1 - [ H3O+ ] ) = 6.5 E-5
⇒ [ H3O+ ]² + 6.5 E-5 [ H3O+ ] - 6.5 E-6 = 0
⇒ [ H3O+ ] = 2.517 E-3 M
c) pH = - log [ H3O+ ]
⇒ pH = - Log ( 2.517 E-3 )
⇒ pH = 2.599