recall the reactants and conditions by which alkanes can beproduced

Alkanes can be produced through various methods, including:

1. Hydrogenation of Alkenes: This is the addition of hydrogen (H2) to an alkene in the presence of a catalyst such as platinum, palladium or nickel. The double bond of the alkene is broken, and a hydrogen atom is added to each carbon.

2. Cracking of Higher Alkanes: This involves breaking down complex hydrocarbons into simpler ones. This is usually done by heating the higher alkane at high temperatures, either in the presence or absence of a catalyst.

3. Carbonation of Methane: Methane can react with carbon dioxide at high temperatures to produce ethane.

4. From Carbon and Hydrogen: Alkanes can also be synthesized from carbon and hydrogen. This is done at high temperatures and pressures, and usually in the presence of a catalyst.

5. Fischer-Tropsch Synthesis: This is a collection of chemical reactions that converts a mixture of carbon monoxide and hydrogen into liquid hydrocarbons. It is commonly used in industries to produce synthetic lubrication oil and synthetic fuel.

Remember, the conditions for these reactions generally involve high temperatures, high pressures, and the presence of a catalyst.