Question

A. Density of water 10.0mL 30.0mL 500ml Mass of empty so ml cylinder 20.7779 20.7779 20.7779 Mass of cylinder + Water 31.314g 50.837g 70.5229 mass of water Density of sample DEM Merck Book Density at

Answer 1

A. Density of water

	10 mL	30 mL	50 mL
Mass of empty 50 mL cylinder	20.777 g	20.777 g	20.777 g
Mass of cylinder + water	31.314 g	50.837 g	70.522 g
Mass of water	31.314 − 20.777 = 10.537 g	50.837 − 20.777 = 30.06 g	70.522 − 20.777 = 49.745 g
Density of sample	10.537 g /10 mL = 1.053 g/mL	30.06 g / 30 mL = 1.002 g/mL	49.745 g / 50 mL = 0.994 g/mL

Mass of water = (Mass of cylinder + water) − Mass of empty 50 ml cylinder

Density of sample = Mass of water / volume of sample

2. Accuracy and precision of volumetric devices

		Graduated Cylinder (10 mL)	Pipette (10 mL)
Temperature of water		22.5 oC	22.5 oC
Mass of empty 50 mL beaker		30.468 g	30.468 g
Mass of beaker + 10 mL water	Trial 1	41.081 g	40.384 g
Mass of beaker + 10 mL water	Trial 2	41.127 g	40.390 g
Mass of beaker + 10 mL water	Trial 3	40.978 g	40.392 g
Mass of 10 mL water	Trial 1	41.081 − 30.468 = 10.613 g	40.384 − 30.468 = 9.916 g
Mass of 10 mL water	Trial 2	41.127 − 30.468 = 10.659 g	40.390 − 30.468 = 9.922 g
Mass of 10 mL water	Trial 3	40.978 − 30.468 = 10.51 g	40.392 − 30.468 = 9.924 g