No, there is no unbranched alkane containing 49 hydrogen atoms. Here's why:

* Alkane Formula: The general formula for unbranched alkanes is C_nH_2n+2, where 'n' represents the number of carbon atoms.

* Hydrogen Count: This formula tells us that for every carbon atom in an unbranched alkane, there are two more hydrogen atoms plus two extra.

* Odd Number of Hydrogens: An alkane with 49 hydrogens would require an odd number of carbon atoms to satisfy the formula. However, the formula always results in an even number of hydrogens because 2n+2 is always even.

Conclusion: An unbranched alkane cannot have an odd number of hydrogen atoms.