A technician is checking an unknown liquid taken from a fuel storage system. The liquid does not mix with water.
The technician transfers some of the liquid from a sample bottle into a measuring cylinder. The bottle is capped when each mass reading is taken.
| Stage of the investigation | Reading |
|---|---|
| capped bottle before the transfer | 238.6 g |
| capped bottle after the transfer | 160.2 g |
| volume delivered into the measuring cylinder | 70.0 cm3 |
The density of water is 1.0 g/cm3.
Calculate the mass transferred from the bottle to the measuring cylinder.
Calculate the density indicated by these readings in g/cm3\text{g/cm}^{3}g/cm3.
Give the technician's result in kg/m3\text{kg/m}^{3}kg/m3.
A fresh portion of the unknown liquid is added to a test tube containing water. The test tube is left undisturbed for a few minutes.
Explain which liquid will form the lower layer.
For a repeat of the investigation, the technician rinses the measuring cylinder with water. Water droplets remain inside when the unknown liquid is added.
Suggest one change to the procedure that removes this source of error.
87 exam-style questions on Edexcel GCSE Physics 14.1 Density and states of matter, covering 14.1.1 Kinetic theory and states of matter, 14.1.2 Density, and 14.1.3 Density and changes of state. Each one has a worked solution and a mark scheme showing where the marks go.