A chemical change is where new substances are formed, and usually involves either heat or electricity.
From the above 4 options, even though we don't know whether heat or electricity is involved, but we can see that option d is a chemical change because new substance is formed.
The new substance formed is the precipitate, meanwhile all other options does not show the formation of new substances.
Note that State changes is not a chemical change, since it can return to its own form. So a is not correct.
B only shows that it dissolves, but nothing new is formed.
And c is only about evaporation, again, nothing new is formed.
So the answer should be d.
Answer:
to which cations from the salt bridge migrate
Explanation:
A voltaic cell is an electrochemical cell that uses spontaneous redox reactions to generate electricity. It's composed of a cathode, an anode, and a salt bridge.
In cathode, the substance is gaining electrons, so it's reducing, in the anode, the substance is losing electrons, so it's oxidating. The flow of electrons is from the anode to the cathode.
The salt bridge is a bond between the cathode and the anode. When the redox reaction takes place, the substances produce its ions, so the solution is no more neutral. The salt bridge allows the solutions to become neutral and the redox reaction continues.
So, the cathode produces anions, which goes to the anode, and the anode produces cations, which goes to the cathode. Then, the cathode n a voltaic cell is the electrode to which cations from salt bridge migrate and where the reduction takes place.
1/16 of the original sample will remain
Answer:
Arrhenius
H, H₃O⁺
OH, OH⁻
Explanation:
The earliest and simplest definition of acids and bases was suggested by <u>Arrhenius</u>. He/They defined an acid as a substance with <u>hydrogen</u> in its formula that dissociates in water to yield <u>H₃O⁺ </u>and a base as a substance with <u>OH</u> in its formula that dissociates in water to yield<u> OH⁻</u>.
Acid:
An acid is the substance that sour in taste and turns the color of litmus paper from blue to red.
pH of acid is less than seven.
Base:
An acid is the substance that bitter in taste and turns the color of litmus paper from red to blue.
The pH of base is 7-14.
Arrhenius gives the simplest definition of acid and base.
Arrhenius acid:
A substance that increase the concentration of hydronium ion in solution is called acid.
HNO₃ → H⁺ + NO₃⁻
(H₂O)
Arrhenius base:
A substance that increase the concentration of OH⁻ ion in solution is called base.
KOH → K⁺ + OH⁻
Answer is 300K. I’ve included how I got that step by step in the photo below. Hope this helps!