(2) at the cathode in an electrolytic cell and at the anode in a voltaic cell
(3) at the anode in both an electrolytic cell and a voltaic cell
(4) at the anode in an electrolytic cell and at the cathode in a voltaic cell
Answer : The correct option is, (3) at the anode in both an electrolytic cell and a voltaic cell.
Explanation :
As we know that there are two types of cell which are, electrolytic cell and electrochemical cell or galvanic cell.
Electrolytic cell : It is defined as the cell in which the chemical reaction occurs by passing of the current from external source.
In this electrolytic cell, the oxidation occurs at anode which is a positive electrode and reduction occurs at cathode which is a negative electrode.
Electrochemical cell : It is defined as the cell in which the chemical reaction occurs with the production of electric potential difference between the two electrodes. It is also known as voltaic cell.
In this cell, the oxidation occurs at anode which is a negative electrode and reduction occurs at cathode which is a positive electrode.
From this we conclude that, the oxidation occurs at the anode in both an electrolytic cell and a voltaic cell.
Hence, the correct option is, (3) at the anode in both an electrolytic cell and a voltaic cell.
b. Oxygen
c. Hydrogen
d. Nitrogen
Answer: The correct answer is Option d.
Explanation:
Dry air is composed of a mixture of gases like argon, oxygen, nitrogen, carbon dioxide and many other gases present in trace amount.
The percentage of these gases by volume in dry air is:
Carbon dioxide = 0.03%
Argon = 0.93%
Oxygen = 20.95%
Nitrogen = 78.09%
Hydrogen = Trace amounts
From the above percentage values, we can easily say that nitrogen has the highest percentage by volume in dry air. Hence, the correct option is d.
b. hazardous
c. domestic
Answer: Option (b) is the correct answer.
Explanation:
When a substance is used and thrown away which can lead to damage in the environment as it may [produce some toxic or hazardous gases is known as a hazardous waste.
These wastes can be solid, liquid or gaseous.
For example, batteries, kerosene, garden chemicals etc are all hazardous waste.
A domestic waste is a waste thrown by a household which may include paper, vegetable waste, cardboard, yard clippings etc.
Thus, we can conclude that hazardous wastes are solid, liquid, or gas wastes that are toxic, flammable, corrosive, reactive, or radioactive.