You're asking about the general formula for alkanes, which tells you how many hydrogens are in an alkane with a given number of carbons.

The general formula for alkanes is: C_nH_2n+2

Here's what it means:

* C_n: This represents 'n' number of carbon atoms.

* H_2n+2: This represents the number of hydrogen atoms. You calculate it by taking twice the number of carbon atoms (2n) and adding 2.

Example:

Let's say you have a 5-carbon alkane (pentane):

* n = 5

* 2n + 2 = (2 * 5) + 2 = 12

So, pentane (C₅H₁₂) has 12 hydrogen atoms.