Chemistry - Study Mode
[#641] The mass of P 4 O 10 that will be obtained from the reaction of 1.33 gram of P 4 and 5.07 of oxygen is
Correct Answer
(B) 3.05 gram
Explanation
Solution: Balanced chemical equation: P 4 + 5O 2 --------> P 4 O 10 1 mol 5 mol 1 mol 124g 160g 284g Here limiting reagent is P 4 . So, 124g of P 4 produce P 4 O 10 = 284g Therefore, 1.33g of P 4 produce P 4 O 10 = (284/124)*1.33 = 3.05g
[#642] The octane number of zero is assigned to
Correct Answer
(B) n-heptane
Explanation
Solution: n-heptane is defined as the zero point of the octane rating scale. 2,2,4-Trimethylpentane has an octane rating of 100, whereas n-heptane has an octane rating of 0. The octane number is based on an arbitrary scale which is a measure of its ability to resist knocking, as it burns on combustion.
[#643] The metal that is used as a catalyst in the hydrogenation of oils is
Correct Answer
(A) Ni
Explanation
Solution: Although nickel is the preferred catalyst for hydrogenation of fats and oils, the use of other metals such as palladium, platinum, ruthenium, and rhodium leads to products with less trans compounds.
[#644] The most abundant rare gas in the atmosphere is
Correct Answer
(C) Ar
Explanation
Solution: The most abundant rare gas in the atmosphere is Argon (Ar).
[#645] Which one of the following elements is an example of noble gas ?
Correct Answer
(D) Helium
Explanation
Solution: Helium is an example of noble gas.