1.
What
is the essential component of a biodiesel
Correct Answer
A. Consists of long-chain alkyl esters
Explanation
Biodiesel is a type of fuel that is made from renewable sources such as vegetable oils or animal fats. The essential component of biodiesel is long-chain alkyl esters, which are formed through a chemical process called transesterification. These esters have similar properties to petroleum diesel, making biodiesel a suitable alternative fuel. The statement "Consists of long-chain alkyl esters" correctly identifies the essential component of biodiesel.
2.
What is an Ester
Correct Answer
C. Chemical compounds derived by reacting an oxoacid with a hydroxyl compound
Explanation
The correct answer is "chemical compounds derived by reacting an oxoacid with a hydroxyl compound." Ester is a type of compound that is formed when an oxoacid reacts with a hydroxyl compound. This reaction results in the formation of an ester and water. Esters are commonly used in various industries, including fragrance, flavor, and pharmaceuticals, due to their pleasant smell and taste. They also have important applications in the production of plastics, solvents, and lubricants.
3.
How
long does it take for biodiesel to biodegrade
Correct Answer
C. 2 weeks
Explanation
Biodiesel is a renewable fuel made from vegetable oils or animal fats. It is designed to biodegrade relatively quickly compared to fossil fuels. The correct answer, 2 weeks, suggests that biodiesel takes a relatively short amount of time to break down naturally in the environment. This is due to its composition, which allows it to be broken down by microorganisms. Biodiesel's biodegradability is an important factor in its environmental impact and sustainability.
4.
Which
is a possible source of biodiesel
Correct Answer
A. Peanuts
Explanation
Peanuts are a possible source of biodiesel because they contain high levels of oil, which can be extracted and converted into biodiesel through a process called transesterification. Biodiesel is a renewable and environmentally friendly alternative to traditional diesel fuel, and using peanuts as a source helps reduce dependence on fossil fuels and decreases greenhouse gas emissions.
5.
Which
of the following is a possible element for an inert electrode
Correct Answer
C. GrapHite
Explanation
Graphite is a possible element for an inert electrode because it is chemically stable and does not react with the substances present in the electrolyte. Inert electrodes are used in electrolytic cells to conduct electricity and facilitate the transfer of electrons during the electrolysis process. Gold, silver, and copper are not considered inert electrodes as they can react with the electrolyte or the substances being electrolyzed, leading to unwanted side reactions and affecting the accuracy of the electrolysis process.
6.
Which
ion of the following elements would be preferentially discharged over H+
ions
Correct Answer
D. Silver
Explanation
Silver would be preferentially discharged over H+ ions because it has a lower reduction potential than hydrogen. In other words, silver has a greater tendency to gain electrons and be reduced compared to hydrogen. Therefore, in a redox reaction, silver ions would be reduced to silver metal while H+ ions would remain in their oxidized state. This preference for silver over hydrogen is due to the difference in their reduction potentials.
7.
How
does electroplating prevent corrosion of an item
Correct Answer
D. It plates an object with another material that will not corrode
Explanation
Electroplating prevents corrosion of an item by covering it with a layer of another material that is resistant to corrosion. This additional layer acts as a barrier between the item and the external environment, preventing any corrosive substances from coming into contact with the item's surface. By doing so, the electroplating process helps to protect the item from rust, oxidation, and other forms of corrosion, thereby increasing its lifespan and maintaining its appearance.
8.
What is a galvanic cell?
Correct Answer
A. Is an electrochemical cell that derives electrical energy from chemical reactions
Explanation
A galvanic cell is an electrochemical cell that derives electrical energy from chemical reactions. This type of cell consists of two half-cells, each containing an electrode and an electrolyte solution. The chemical reactions occurring at the electrodes produce a flow of electrons, which can be harnessed as electrical energy. The galvanic cell is commonly used in batteries and fuel cells to provide power for various devices and systems.