Calculate the mass of 1.25 mol ammonium sulfide, (NH4)2S. *

85g

Explanation:

To convert the moles of a substance to grams we need to know the molar mass of the substance. We, as first, must obtain the molar mass of (NH₄)₂S as follows:

There are 2 atoms of N, 8 of H and 1 of S:

N = 2*14g/mol = 28g/mol

H = 8*1g/mol = 8g/mol

S = 1*32g/mol = 32g/mol

Molar mass: 68g/mol

That means 1 mole of (NH₄)₂S has a mass of 68g.

1.25moles have a mass of:

1.25moles * (68g/mol) =

quartz

explanation:

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.