1. what are the characteristics of all chemical reactions? 2. why does temperature affect how fast a chemical reaction occurs? (use kinetic energy in your answer.) 3. what is stored in chemical bonds? 4. what is wrong with this chemical equation? (hint: think about the law of conservation of mass.) balance it. h2 + o2 > h2o 5. why do certain chemical reactions require a catalyst? 6. how does energy get stored in chemical bonds? use a different example than what was mentioned in the article to explain your answer. 7. how does pressure affect the rate of a reaction? 8. why does adding more or less of a substance change the rate the reaction occurs? 9. what is the difference between a compound and a molecule? ***click the molecule link in the article to find the answer. 10. what would be an example of a catalyst from a lab you did in class this year?

Im answering question 2
Because it increases the kinetic energy of reactants and so the frequency of collision between reactants. Thus, provided the temperature is not too high to lead to denaturation of reactants, increase in temperature increases the rate of reaction

And for ques. 7:
It gets affected when gaseous reactants in which products formed have less volume than reactants, so increase in pressure increases the rate of reaction

Answerthis solution will not form a precipitateexplanationsolubility equilbrium:         pbf₂(s)  ⇄ pb²⁺(aq) + 2 f⁻(aq)the solubility product expression is    (we exclude solids from the equilibrium expression).now suppose we have the trial ion product q, which we can define as    then, we can interpret  q as the product of the concentration of the ions that we have and ksp as the product of the ion concentrations that are needed to form a saturated solution.if q > ksp, then that implies that there will be a surplus of ions that exceed the amount that is required to form a saturated solution. a precipitate will then form (the precipitate continually  forms until the surplus ions are removed and q is decreased to ksp's value).if q = ksp, the saturated solution that forms is barely saturated and the precipitate will be minimal.if q < ksp, then the ion concentration will not be enough to form a saturated solution (so no precipitate).using our information, we calculate the trial ion product:     since q = 2.7  × 10⁻⁸ < ksp =  4  ×  10⁻⁸, a precipitate will not form.

Answer///an early form of the atomic theory; dalton atomic theory;