mole stoichometry: How many moles of hydrogen are needed to completely react with 2.00 moles of oxygen gas?

Draw the structure for 5-isopropyl-2-methyl-3-nonene

As changes in energy levels of electrons increase, the frequencies of atomic line spectra they emit

Before it was launched, a helium-filled balloon had a pressure of 201 kpa at a temperature of 27°c. at an altitude of 15,000 m, the pressure had decreased to 2.5 kpa and the temperature had dropped to -14 °c. the volume of the balloon increased to 59.3 m3. what is the original volume of the balloon? 13 m3 0.85 m3 0.077 m3 1.17 m3