In class, students were given the following problem: "aluminum satellite dishes resist corrosion because aluminum reacts with oxygen gas to form a coating of aluminum oxide (al2o3). what is the mass of al2o3? "

a) sally solved the problem by first finding the molar mass of aluminum oxide. she calculated the molar mass of al2o3 as 43.0 g/mol. this is not the correct molar mass however. what did sally do wrong?

b) after finding the molar mass of al2o3, jacob set up the following conversion. (i'll add a pic)

is this the correct set up for the problem?

pure water does not conduct electricity very well. however, when certain substances are dissolved in water, the solution does conduct electricity. you can make a simple device that shows how well a solution conducts electricity. this device uses a flashlight bulb to indicate how well the solution conducts electricity. the better the solution conducts electricity, the brighter the bulb will glow.

explanation:

answer: enthalpy

explanation:

for a exothermic reaction, the energy is released i.e. the energy of the products is lower than the energy of the reactants.

= enthaply

= energy of products

= energy of reactants

as , thus comes out to be negative. negative value of enthalpy shows that the reaction is exothermic.