Chemistry - Study Mode
[#866] The compound that has the least value for octane number is :
Correct Answer
(D) N-heptane
Explanation
Solution: Octane rating or octane number is a standard measure of the performance of a motor or aviation fuel. The higher the octane number, the more compression the fuel can withstand. Isooctane (upper) has an octane rating of 100 whereas n-heptane has an octane rating of 0.
[#867] The length of double bond is _______ than single bond.
Correct Answer
(A) Shorter
Explanation
Solution: Double bonds are shorter than single bonds because p-orbital overlap is maximized.
[#868] An example of heterocyclic compound is
Correct Answer
(B) Furan
Explanation
Solution: The most common heterocycles are those having five- or six-membered rings and containing heteroatoms of nitrogen (N), oxygen (O), or sulfur (S). The best known of the simple heterocyclic compounds are pyridine, pyrrole, furan, and thiophene.
[#869] In organic compounds, nitrogen is estimated by
Correct Answer
(D) Dumas method
Explanation
Solution: Duma's method can be used to estimate nitrogen in all type of organic compounds. Detection of nitrogen is done by Lassigne's test. Estimation of phosphorus is done by Carius method.
[#870] Heavy metals got their name because compared to other atoms they have
Correct Answer
(B) Higher atomic masses
Explanation
Solution: Arsenic, beryllium, cadmium, chromium, lead, manganese, mercury, nickel, and selenium are some of the metals called ‘heavy’ because of their high relative atomic mass. They persist in nature and can cause damage or death in animals, humans, and plants even at very low concentrations.