The european union has adopted a chemicals law, known as reach, that takes a very different approach. companies manufacturing or importing chemicals into the eu in quantities greater than one ton must register them with a specialized agency. companies bear the burden of identifying and managing the risks posed by their substances. chemicals of high concern (such as carcinogens, toxins, and bioaccumulative compounds) require specific authorization, and companies must demonstrate to the agency how the substances can be safely used, communicate this information to users, and make efforts to find safer substitutes. the agency can ban substances if the risks are deemed unmanageable. how would you compare this approach to the statutes discussed in chapter 8? should the us develop something similar to regulate toxic substances?

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.

answer is: empirical formula is tl₂o. if we use 100 grams of compound, tha:

m(tl) = 96.2%  · 100 g ÷ 100%.

m(tl) = 96.2 g.

n(tl) = m(tl)  ÷ m(tl). n(tl) = 96.2 g  ÷ 204.4 g/mol.

n(tl) = 0.47 mol. m(o) = 3.77 g. n(o) = m(o)  ÷ m(o). n(o) = 3.77 g  ÷ 16 g/mol. n(ag) = 0.235 mol. n(tl) . n(o) = 0.47 mol : 0.235 mol /0.235. n(tl) . n(o) = 2 : 1.

m(tl₂o) = 204.4 g/mol  · 2 + 16 g/mol = 424.8 g/mol.

m(compound) = 456. 8 g/mol - 424.8 g/mol = 32 g/mol ( 2 oxygens); tl₂o₃.