The piece of lab equipment that would be least useful in finding the precise density of an unknown liquid is a Bunsen burner.

Here's why:

* Density is a ratio of mass to volume. A Bunsen burner is used for heating, which won't directly help you measure either mass or volume.

* To determine density, you need accurate measurements. You'll need equipment like a graduated cylinder (for volume) and a balance (for mass).

Let's consider some other pieces of equipment and why they *would* be useful:

* Graduated cylinder: Used to measure the volume of the liquid accurately.

* Balance: Used to measure the mass of the liquid accurately.

* Beaker: While not as precise as a graduated cylinder, a beaker can still provide a decent volume measurement.

* Pipette: Useful for transferring small, precise volumes of liquid.

Let me know if you have any more questions!