Determine the formula for alkyne, the relative density of vapor for hydrogen is 55.

Given: Alkyne – hydrocarbon;
D (H2) = 55;
M (H2) = 2 g / mol;
Find: ShNu -?
Let’s carry out the solution in accordance with the conditions of the problem:
1. The general formula of a hydrocarbon belonging to the class of alkynes is CnH2n – 2.
2.M (CxHy) = M (H2) * D (H2) = 2 * 55 = 110 g / mol.
3. To determine the formula, we make calculations:
CnH2n – 2 = 110;
12n + 2 – 2 = 110;
12n = 106;
n = 8;
C8H14;
4. Verification: M (C8H14) = 12 * 8 + 14 = 110 g / mol.
Answer: C8H14 is octine, a representative of the alkynes class.