for a particular isomer of c8h18, the combustion reaction produces 5099.5 kj of heat per mole of c8h18(g) consumed, under standard conditions. c8h18(g)+252o2(g)⟶8co2(g)+9h2o(g)δH ∘rxn=−5099.5 kj/mol what is the standard enthalpy of formation of this isomer of c8h18(g)?

When do you think it’s best to take the psat (what grade year / when in the year)?

Afish fossil is found in a rock. a foot bone and tooth are found in an older layer of the same rock. what can scientists learn from the rock? a) the area changed from land to water. b) the area changed from water to land. c) the area has always been land. d) the area was once an ocean.

Aschool cafeteria has 40 tables. 35% of the tables have 8 chairs at each table. the remaining 65% of the tables have 6 chairs at each table. complete the model. then complete the statements to find the total number of chairs in the cafeteria.