Here is a generic thermochemical equation involving reactants A and B and products C and D: A + 2B 2C + D + 78.3 kJ
What does the expression + 78.3 kJ signify?
An endothermic reaction that releases 78.3 kJ of heat regardless of the amounts of reactants

An exothermic reaction that releases 78.3 kJ of heat regardless of the amounts of reactants

An endothermic reaction that absorbs 78.3 kJ of heat per mole of reactant A

An exothermic reaction that releases 78.3 kJ of heat per mole of reactant A

Agroup of students is studying convection currents. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other in an area with warm air. after 10 minutes, the balloons are released from a height of 1 meter. which of the following do the students most likely observe? a. the balloons both rise. the cold balloon is larger than the warm balloon. b. the balloons rise at the same rate. both balloons are the same size. c. the warm balloon expands and rises. the cold balloon shrinks and sinks. d. the cold balloon expands and rises. the warm balloon shrinks and sinks.

Which of the following statements concerning the influence of culture on ethnic identity formation is accurate? a. one will reject ethnic identity if cultural stereotypes are encountered. b. if one’s ethnic city is different from the dominant cultural group, then one’s ethnic identity you will become weekend. c. if an the ethnic group is excepted by dominant culture, then ethnic identity formation can be a difficult process. d. similarity to the dominant culture can determine how easy it is for one to except ethnic differences.

How many moles are in 43.9 l of oxygen