Asample of 0.900 mol n2o is placed in a sealed
container, where it decomposes irreversibly to n2 and o2
in a first-order reaction. after 42.0 min, 0.640 mol n2o
remains. how long will it take for the reaction to be
90.0% complete?

Between 2014 and 2016, more than 25,000 children in flint, michigan, drank water that was contaminated with lead from lead pipes. during this time, the city claimed the water was safe to drink. which of these actions could the city have taken to ensure that the drinking water was free from lead?

The covalent compound acetylene, which is the fuel of the oxyacetylene torch used by welders, has the molecular formula c2h2. the covalent compound benzene, a commercial solvent, has the molecular formula c6h6 each of these covalent compounds contains carbon and hydrogen atoms in a one-to-one ratio. would it be correct to write the chemical formulas of each as ch? explain.

Compare and contrast physical changes with chemical changes.