Final answer:
The mass of 346 cm³ of polythene with a density of 0.95 g/cm³ is calculated to be 328.7 g. It should be rounded to 329 g to maintain the correct number of significant figures.
Step-by-step explanation:
To calculate the mass of polythene, we use the formula:
mass = density × volume
Given that the density of polythene is 0.95 g/cm³ and the volume is 346 cm³, the calculation is as follows:
mass = (0.95 g/cm³) × (346 cm³)
mass = 328.7 g
To maintain the correct number of significant figures, we should round our answer to three significant figures because the volume measurement has only three significant figures.
Therefore, the mass of polythene is approximately 329 g when rounded to two decimal places.