Question

The mass of a 270. mL beaker is 178 g when empty. Determine its mass when filled with the following substances.

(a) water (density 0.9970 g/cm³ at 20°C)

____ g
(b) alcohol (density 0.7893 g/cm³ at 20°C)
____ g
(c) mercury (density 13.546 g/cm³ at 20°C)
____ g
(d) Explain why mercury containing pollutants are usually found in the mud at the bottom of a lake of stream.

-Mercury has a negative charge and is attracted to the positively charged particles on the lake or stream bed.

-Mercury containing pollutants do not float.    

-Mercury is denser, and therefore sinks to the bottom of the lake or stream.

Answer 1

a) empty volume = 270 ml

   density of water = 0.9970 g/ml

mass of water = density x volume

                         = 0.9970 x 270

                          = 269.19 g

total mass = mass of water + mass of beaker

                 = 269.19 + 178

                  = 447.19g

when water filled total mass = 447.19g

(b) density 0.7893 g/cm³

alcohol weight = 270 x 0.7893= 213.11g

total weight = 213.11 + 178

                     = 391.11

total weight = 391.11g

(c) mercury weight = 13.546 x 270

                                 = 3657.42

total weight = 3657.42 + 178

              = 3835.42 g

(d) correct answer : Mercury is denser, and therefore sinks to the bottom of the lake or stream.