General chemistry Questions & Answers

General chemistry Questions & Answers - CORRECT ANSWER2Al2O3(s) → 4Al(s)+3O2(g), ΔH = +801 kcal (+3350 kJ ) How many kilocalories are required to produce 1.96 mol of aluminum? - CORRECT ANSWER- 392 kilocalories divide the given change in heat by the mole of 4Al and then multiply with the one we want to produce 4. What can be predicted for the reaction below? 2 Al(s) + 3 Cl2(g) = 2 AlCl3(s) + 337 kcal - CORRECT ANSWERa positive change in S reaction means... - CORRECT ANSWER- an increase in disorder for the reaction and the opposite is same for a negative change average bond dissociation energy - CORRECT ANSWERbond (dissociation) energy - CORRECT ANSWER- the amount of energy that must be supplied to break a bond and separate the atoms in an isolated gaseous molecule bonds - CORRECT ANSWER- when it's breaking energy is absorbed. When it's forming energy is released. change in energy occurs when... - CORRECT ANSWER- reactants interact bonds break apart products are formed (new bonds formed) chemical reaction - CORRECT ANSWER- if the product have less potential energy than the reactant then the products are more stable than the reactants endergonic event - CORRECT ANSWER- a non spontaneous reaction or process that absorbs free energy and has a positive free energy charge. endothermic - CORRECT ANSWER- a chemical change that absorbs heat examples: bond breaking, ice melting. Heat absorbed means that Q has a (+) value (E gained) endothermic reaction decomposition reaction - CORRECT ANSWER- 22 kcal + 2NH3(g) N2(g) + 3H2(g) endothermic reactions - CORRECT ANSWER- if the energy required to break the bonds is larger than the energy released when the bonds are formed there will need to be an external supply of energy entropy (S) - CORRECT ANSWER- a measure of the randomness of a chemical system