Question

Составте молекулярные формулы алканов, в молекулах которых: а) 5 атомов углерода б) 8 атомов углерода в) 11 атомов углерода г) 11 атомов углерода д) 20 атомов водорода е) 32 атома водородп

Answer 1

Общая формула алканов: C(n)H(2n+2)
По ней мы и вычислим формулы.
а) С5Н12
б) С8Н18
в) С11Н24
г) С11Н24
д) С20Н42
е) С32Н66

Answer 2

I can answer your question in detail. Alkanes are hydrocarbons that have only single bonds between carbon atoms. Their general molecular formula is C_nH_2n+2, where n is the number of carbon atoms. To find the molecular formulas of alkanes with a given number of carbon or hydrogen atoms, we can use this formula and solve for n. For example:

- To find the molecular formula of an alkane with 5 carbon atoms, we can substitute n = 5 in the formula and get C₅H₂₍₅₎₊₂ = C₅H₁₂. This is the molecular formula of pentane, the simplest alkane with 5 carbon atoms. - To find the molecular formula of an alkane with 8 carbon atoms, we can substitute n = 8 in the formula and get C₈H₂₍₈₎₊₂ = C₈H₁₈. This is the molecular formula of octane, the simplest alkane with 8 carbon atoms. - To find the molecular formula of an alkane with 11 carbon atoms, we can substitute n = 11 in the formula and get C₁₁H_2(11)+2 = C₁₁H₂₄. This is the molecular formula of undecane, the simplest alkane with 11 carbon atoms. - To find the molecular formula of an alkane with 20 hydrogen atoms, we can rearrange the formula to get n = (H - 2) / 2, where H is the number of hydrogen atoms. Then we can substitute H = 20 and get n = (20 - 2) / 2 = 9. This means that the alkane has 9 carbon atoms and its molecular formula is C₉H₂₀. This is the molecular formula of nonane, the simplest alkane with 9 carbon atoms. - To find the molecular formula of an alkane with 32 hydrogen atoms, we can use the same method as above and substitute H = 32. Then we get n = (32 - 2) / 2 = 15. This means that the alkane has 15 carbon atoms and its molecular formula is C₁₅H₃₂. This is the molecular formula of pentadecane, the simplest alkane with 15 carbon atoms.

I hope this helps you understand how to find the molecular formulas of alkanes. If you want to learn more about alkanes and their properties, you can check out some of the web search results I found for you . Have a nice day!