The density of benzene is approximately 0.879 g/mL at room temperature (20°C).

To find the weight of 1 liter (1000 mL) of benzene, we can use the following calculation:

* Weight = Density x Volume

* Weight = 0.879 g/mL x 1000 mL

* Weight = 879 grams

Therefore, a liter of benzene weighs approximately 879 grams.