Write the chemical formulas for (a) methane, (b) ethane, (c) propane, and (d) butane. Give one practical use for each of these hydrocarbons.

Alkanes form a fundamental group of hydrocarbons in organic chemistry characterized by their simple structure and single covalent bonds. Each carbon atom in an alkane has four bonds. When bonded with hydrogen, the formula for alkanes follows a general pattern: \( C_nH_{2n+2} \), where \( n \) is the number of carbon atoms.

Starting with methane, the simplest alkane with one carbon atom (\( C_1H_{2(1)+2} = CH_4 \) ), we then increase the carbon chain by one to determine the chemical formulas for ethane, propane, and butane. Ethane (\( C_2H_{2(2)+2} = C_2H_6 \) ), propane (\( C_3H_{2(3)+2} = C_3H_8 \) ), and butane (\( C_4H_{2(4)+2} = C_4H_{10} \) ).

Visualization: Imagine a string of pearls where each pearl is a carbon atom. The chain has a certain number of pearls, and each pearl connects with single lines (representing single bonds) to four neighbors—other pearls (carbons) or smaller beads (hydrogens).

Naming organic compounds is an essential skill in chemistry. The names of alkanes are derived by combining a prefix that indicates the number of carbon atoms with the suffix '-ane' to signify that the compounds are alkanes. For example, 'meth-' signifies one carbon, 'eth-' signifies two, 'prop-' signifies three, and 'but-' signifies four.

For the compounds in our exercise, 'methane' represents a one-carbon alkane, 'ethane' a two-carbon, 'propane' a three-carbon, and 'butane' a four-carbon alkane. This system of nomenclature allows chemists to derive the structure of the compound from its name and vice versa. This standardized naming convention greatly facilitates the study and communication of organic compounds within the scientific community.

Hydrocarbons are not just academic, they are indispensable in daily life. Methane, known chiefly as natural gas, is used extensively for domestic cooking and heating due to its clean-burning nature. Ethane, less commonly known to the public, is a vital petrochemical feedstock, cracking it produces ethylene, a precursor for polyethylene plastic manufacturing.

Propane's versatility sees it as a fuel for barbecue grills, to power engines, and in residential heating systems. Portable and readily available, it's a popular energy source. Butane finds its niche mainly as a lighter fuel and in portable camping stoves due to its ease of liquefaction and transportability. These practical applications of hydrocarbons illustrate their critical role in modern technology and industry, making an understanding of their chemistry highly relevant.