Yes, you will pay tax on your capital gain from selling the land. It doesn't matter what you used the money for.
There used to be a rule that you could defer (not eliminate) the tax on the gain from selling your primary home if you used the money to buy a new primary home. That rule was removed from the tax law in 1997. And anyway, it only applied to selling the home you were living in, not selling land with no building on it.
