a) Degree of unsaturation: 5.
C8H8 corresponds to the saturated alkane C8H18, octane, which has eight hydrogen atoms per molecule. Theoretically, it will take five hydrogen molecules H2 to convert C8H8 to C8H18. C8H8 therefore has and DoU of 5.
b) Number of triple bonds: 2.
Only triple bonds are hydrogenated over a Lindlar catalyst. A triple bond can be converted only to a double bond, but not a single bond, under such settings. Each triple bond would absorb only one molecule of hydrogen.
Two hydrogen molecules are absorbed for each C8H8 molecule. Each molecule therefore contains two triple bonds.
c) Number of double bonds: 1.
Palladium catalysts convert both triple and double bonds to single bonds while preserving any rings. Each triple bond would consume two hydrogen molecules, whereas each double bond would consume one.
The two triple bonds as determined in b) account for the consumption of four out the five hydrogen molecules. One double bond shall be responsible for the other.
d) There is no ring in C8H18.
The molecular formula of C8H18 indicates an DoU of five. Each double bond contributes to the DoU by one, each triple bond by two. The double bond and the two triple bonds would have accounted for all five degrees of unsaturation. There are thus no spare DoU available for the presence of rings.
The described hydrocarbon with formula C8H8 has 4 degrees of unsaturation initially, indicating the presence of 2 triple bonds converted by Lindlar catalyst. The remaining 2 degrees of unsaturation are attributed to a ring structure.
The concept being evaluated here is degrees of unsaturation (also known as the index of hydrogen deficiency) in organic molecules and how they refer to the number of double bonds, triple bonds, or rings that a molecule contains.
At first, we can calculate the Index of Hydrogen Deficiency (IHD) which is calculated using the formula (2C+2+X-N)/2, where C is the number of Carbon atoms, X is the halogens and N is the nitrogens. For a molecule with formula C8H8, this equates to (2×8+2-8)/2 = 4. Therefore, your hydrocarbon has 4 degrees of unsaturation.
Now, considering the information that under Lindlar catalyst, the compound absorbed 2 equivalents of H2, which suggests the presence of 2 triple bonds converted to 2 double bonds. This leaves us with 2 degrees of unsaturation which must be in the form of a ring. However, on hydrogenation over a palladium catalyst, 5 equivalents of H2 indicate that these 2 double bonds from the Lindlar reaction and the ring can convert completely to single bonds. So, In summary: a) Degrees of unsaturation: 4 b) Triple bonds: 2 c) Double bonds: 0 (after Lindlar hydrogenation) d) Number of Rings: 1
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Answer:
Gaseous matter
Explanation:
Hydrogen chloride gas is formed from the combination of volumes of hydrogen gas and chlorine gas in equal proportion. It is one of the hydrogen halides I.e a compound formed from the combination of hydrogen and halogens.
Hydrogen chloride gas is a colorless gas.
Both hydrogen gas and chlorine gas can be obtained through the electrolysis of brine in the chlor alkali process.
Cl2(g) + H2(g) → 2 HCl(g)
The combination is exothermic and thus heat is released to the surroundings. A construction called HCl burner is used to carry out the reaction because of the heat given off. The produced gas is then absorbed in water