Some chemical reactions need energy in the form of heat to take place, while others give off energy. Read each of the phrases that describe endothermic or exothermic reactions and select the type of reaction the description represents. it is either endothermic or exothermic reaction for all

1.some energy is released as light
[ Select ]
2.energy released is greater than the energy needed to break bonds
[ Select ]
3.need continuous source of energy
[ Select ]
4.leaves the surroundings feeling cold
[ Select ]
5.some energy is released as heat
[ Select ]
6.more energy needed to break bonds of the the reactants than is released
[ Select ]

According to the diagram; a) identify the anode of the cell and write the half-reaction that occurs there b) write the overall equation for the reaction that occurs as the cell operates c) calculate the value of the standard cell potential ,e cell. d)write the shorthand notation of the cell above e)indicate the flow of the electrons on the diagram

You mix the pks of succinic acid are 4.21 and 5.64. how many gramsa graduate student at sdsu wants to measure the activity of a particular enzyme at ph 4.0. to buffer her reaction, she will use a buffer system based on one of the acids listed below, which acid is most appropriate for the experiment? of monosodium succinate (fw = 140 g/mol) and disodium succinate (fw = 162 g/mol) must be added to 1 l of water to produce a solution with a ph 5.28 and a total solute concentration of 100 mm? (assume the total volume remains 1 liter, answer in grams monosodium succinate, grams disodium succinate, respectively.) volumes of 0.05 m nah2po4 and 0.05 m na2hpo4 (pk's for phosphoric acid are 2.15, 6.82 and 12.38). which of the following best describes the resulting solution?

What is the percent by mass of oxygen in fe2o3