Classify the following to be pure substance or mixture: pure ethanol: 70% rubbing alcohol: orange juice: sugar water: distilled water: mineral water:

Pure Substance

Pure ethanol

Distilled water

Mixture

All others

Explanation:

A mixture can be defined as a substance that contains 2 or more substance in any proportion which are bound to each other physically and can be separated using ordinary physical means

A pure substance on the other hand has a single composition without impurities.

The pure substances here are just the pure ethanol and the distilled water. Both have single compositions and are pure. The other substances are mixtures because they are not of single compositions but their components can be separated by physical means

in 1783 cavendish was working with his hydrogen gas and found that when he burned it and condensed the vapor it was water. this was very significant since it disproved the greek theory of elements completely since water was not a simple substance but the product of two gases. it was lavoisier who hearing of the experiment gave cavendish's gas the name hydrogen ("water-producer") and added that hydrogen burned by combining with oxygen and that water was a hydrogen-oxygen combination.

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.