PLEASE HELP PLEASE Octane (C8H18) is a component of gasoline that burns
according to the following equation:
C8H18(l) + 25/2 O2(g) →8 CO2(g) + 9 H2O(g)
ΔΗχη= -5074.1 kJ
What mass of octane (in g) is required to produce 4910kJ of heat?

According to the tide table below what time of day will the highest tide occur? (2 pt) the highest tide will occur at

For the reaction shown, calculate how many moles of no2 form when each of the following completely reacts. 2n2o5(g)→4no2(g)+o2(g) part a 1.0 mol n2o5 express your answer using two significant figures. nothing mol m o l request answer part b 5.4 mol n2o5 express your answer using two significant figures.

Structure of the atoms: discovery of the nucleus in 1909i need answering all of these questions