1.
In electrolysis, only _____________ ions present can be discharged.
Correct Answer
B. 2 out of 4
Explanation
In electrolysis, only ions that are present in the electrolyte can be discharged. This means that not all ions in the electrolyte will undergo a chemical reaction and be discharged. The correct answer of "2 out of 4" suggests that only two out of the four ions present in the electrolyte will be discharged during electrolysis.
2.
What are the ions present in water?
Correct Answer
B. H+ and OH-
Explanation
Water is a polar molecule, meaning it has a slightly positive end (hydrogen) and a slightly negative end (oxygen). This polarity allows water to dissociate into ions. H+ ions are formed when the hydrogen atom loses its electron, while OH- ions are formed when the oxygen atom gains an electron. Therefore, the correct answer is H+ and OH-.
3.
If the anions in an aqueous solution are
_________ ions, they will be
________.
Correct Answer
B. Halide, discharged
Explanation
If the anions in an aqueous solution are halide ions, they will be discharged. This means that during electrolysis, halide ions will be attracted to the positive electrode (anode) and undergo a chemical reaction, resulting in the production of a halogen gas. This discharge occurs because halide ions have a higher tendency to lose electrons compared to other anions present in the solution.
4.
Which pair of electrolytes is not inert?
Correct Answer
D. Copper and Silver
Explanation
Copper and silver are not inert electrolytes because they can undergo chemical reactions in an electrolytic cell. When an electric current is passed through a solution containing copper and silver ions, copper ions will be reduced at the cathode, while silver ions will be oxidized at the anode. This results in the deposition of copper metal at the cathode and the dissolution of silver metal at the anode. In contrast, mercury, carbon, and silver are inert electrolytes and do not undergo such reactions.
5.
Which metal is used in electroplating cans
to store food?
Correct Answer
C. Tin
Explanation
Tin is used in electroplating cans to store food because it is a non-toxic metal that is resistant to corrosion. It forms a protective layer on the surface of the can, preventing the food from coming into contact with the metal and altering its taste or quality. Tin also has good conductivity, making it suitable for the electroplating process.
6.
In the electrolysis of molten sodium
chloride, what is the yellow green gas formed?
Correct Answer
C. Chlorine
Explanation
During the electrolysis of molten sodium chloride, chlorine gas is formed at the positive electrode (anode). This is because chloride ions (Cl-) are attracted to the positive electrode and undergo oxidation, releasing chlorine gas (Cl2). Therefore, the correct answer is chlorine.
7.
______ are _________ at the anode and _______ at the cathode.
Correct Answer
C. Ions, oxidized, reduced
Explanation
In electrochemical reactions, ions are typically oxidized at the anode and reduced at the cathode. Oxidation is the loss of electrons, which occurs at the anode, while reduction is the gain of electrons, which occurs at the cathode. This fundamental principle applies to various types of cells, including electrolytic cells and galvanic cells.
8.
A cathode is ____________ charged
Correct Answer
B. Negatively
Explanation
A cathode is negatively charged because it is the electrode where reduction occurs during an electrochemical reaction. Reduction involves gaining electrons, which results in a negative charge on the cathode.
9.
An anode is __________ charged.
Correct Answer
A. Positively
Explanation
An anode is positively charged because it is the electrode where oxidation occurs during an electrochemical reaction. Oxidation involves the loss of electrons, which results in a positive charge on the anode.
10.
Which of these is not an application of
electrolysis?
Correct Answer
C. Making leather
Explanation
Electrolysis is a process that involves the use of an electric current to drive a non-spontaneous chemical reaction. It is commonly used in rust removal, electroplating, and the manufacture of bleach. However, making leather does not require the use of electrolysis. Leather production involves various processes such as tanning, dyeing, and finishing, but none of these processes involve the use of an electric current to drive a chemical reaction. Therefore, making leather is not an application of electrolysis.