1.
The molar mass of ethyne is...
Correct Answer
A. 26.04g/mol
Explanation
The molar mass of ethyne (also known as acetylene) is 26.04g/mol. Molar mass is the mass of one mole of a substance, and it is calculated by adding up the atomic masses of all the atoms in the chemical formula. The chemical formula for ethyne is C2H2, which consists of two carbon atoms and two hydrogen atoms. The atomic mass of carbon is 12.01g/mol, and the atomic mass of hydrogen is 1.01g/mol. Therefore, the molar mass of ethyne is (2 * 12.01g/mol) + (2 * 1.01g/mol) = 26.04g/mol.
2.
It was discovered in...
Correct Answer
B. 1836
Explanation
The correct answer is 1836. This means that whatever was discovered, it was found in the year 1836.
3.
It was rediscovered by French chemist Marcellin Berthelot, who coined the name acétylène, in which year?
Correct Answer
A. 1860
Explanation
The correct answer is 1860. Acetylene was rediscovered by French chemist Marcellin Berthelot in 1860. He also coined the name acétylène for this compound.
4.
Its vapor pressure is...
Correct Answer
A. 44.2 atm
Explanation
The correct answer is 44.2 atm. This means that the vapor pressure of the substance in question is 44.2 atmospheres. Vapor pressure is the pressure exerted by a vapor in equilibrium with its liquid or solid phase at a given temperature. In this case, the substance has a vapor pressure of 44.2 atm, indicating that it has a high tendency to evaporate and form a vapor at the given temperature.
5.
What is its density?
Correct Answer
A. 1.097 kg/m3
Explanation
The density of a substance is defined as its mass per unit volume. In this case, the substance has a density of 1.097 kg/m3, which means that for every 1 cubic meter of the substance, it has a mass of 1.097 kilograms.
6.
What happens to its smell when pure?
Correct Answer
A. It has a sweet smell
Explanation
When a substance is described as having a sweet smell, it means that it emits a pleasant and sugary aroma. This indicates that the substance is likely to be pleasant or enjoyable to smell.
7.
It is explosive if mixed with...
Correct Answer
B. Air
Explanation
When a substance is described as "explosive," it means that it has the potential to undergo a rapid and violent chemical reaction. In this case, the correct answer is "Air." This means that if the substance in question is mixed with air, it can react in a way that produces an explosion. It is important to handle and store such substances with caution to prevent any accidents or harm.
8.
Acetylene cannot exist as a...
Correct Answer
B. Liquid
Explanation
Acetylene cannot exist as a liquid because it is a highly flammable gas at room temperature and atmospheric pressure. It is typically stored and transported in high-pressure cylinders as a compressed gas. The low boiling point of acetylene (-84 degrees Celsius) makes it difficult to liquefy and maintain in a liquid state under normal conditions. Therefore, acetylene is commonly used and handled as a gas.
9.
Acetylene is a chemical compound composed of....
Correct Answer
A. Two carbon and two hydrogen atoms
Explanation
Acetylene is composed of two carbon and two hydrogen atoms. This can be determined by looking at the chemical formula for acetylene, which is C2H2. The subscript 2 indicates that there are two atoms of carbon, and the subscript 2 for hydrogen indicates that there are also two atoms of hydrogen. Therefore, the correct answer is two carbon and two hydrogen atoms.
10.
It was prepared by the hydrolysis of calcium carbide, a reaction discovered by Friedrich Wöhler in...
Correct Answer
B. 1862
Explanation
The correct answer is 1862. This is because Friedrich Wöhler discovered the reaction of hydrolysis of calcium carbide in 1862. This reaction involves the reaction of calcium carbide with water to produce calcium hydroxide and acetylene gas. This discovery was significant as it led to the production of acetylene gas, which has various industrial applications, including its use as a fuel for welding and cutting torches.