An empty 25.00 ml volumetric flask has a mass of 20.550 g. when it is partially filled with metal pellets, the mass is 130.278 g. the flask is then filled to the mark with methanol (density = 0.7918 g/ml), and the total mass of the flask, metal, and methanol is 142.419 g. calculate the density of the metal pellets

11.347 g/mL is the density of the metal pellets.

Explanation:

The total mass of the flask, metal, and methanol  = M = 142.412 g

Mass of flask = 25.00 mL

Mass of flask and metal pellets = 130.278 g

mass of flask + mass of pellets = 130.270 g

M = mass of flask + mass of pellets + mass of methanol

142.412 g = 130.270 g + mass of methanol

Mass of methanol = 12.142 g

Volume of methanol = v

Density of the methanol = 0.7918 g/mL

Volume of the flask = V = 25 mL

Volume of the pellets = V'

V = V' + v

V'= V - v = 25 mL - 15.33 mL = 9.67 mL

Density of the metal pellets = d

Mass of the metal pellets = m

Mass of flask and metal pellets = 130.278 g

20.55 g + m = 130.278 g

m = 109.728 g

11.347 g/mL is the density of the metal pellets.

definition

                    entropy is a measure of the randomness or the extent of disorder of a chemical process.

                      enthalpy is a measure of the heat change of a reaction occurring at a constant pressure.

measurement units:

                        entropy is measured in joule per kelvin (jk⁻¹)   whereas enthalpy is measured in joule per mole (jmol⁻¹)

requirements:

                            entropy has no requirements or limits, and its change is measured by the division between the heat change of the chemical process and the temperature.

                              in contrast, enthalpy can only be related to the heat change of the reaction under standard conditions.