What is the energy per mole of photons of light with a wavelength of 690.8 nm?

What is the wavelength of light emitted when an electron in a hydrogen atom undergoes a transition from energy level n = 6 to level n = 1? (c  = 3.00  × 108 m/s, h =  6.63 × 10–34 J·s, RH  =  2.179 × 10–18 J)

​What is the energy of a photon of electromagnetic radiation with a wavelength of 165.2 nm? 

The thermochemical equation for the combustion of methanol is given below.   CH3OH() + 3/2 O2(g) → CO2(g) + 2 H 2O(g) ΔrH° = –638.7 kJ/mol-rxn What is the enthalpy change for the combustion of 8.59 g of CH3OH?

Which of the following is not a valid resonance structure for N3–?

For a proton (mass = 1.673 × 10–27 kg) moving with a velocity of 2.83 × 104 m/s, what is the de Broglie wavelength of the proton (in pm)?

How much heat is liberated at constant pressure if 0.515 g of calcium carbonate reacts with 32.7 mL of 0.498 M hydrochloric acid? CaCO3(s) + 2HCl(aq)  →  CaCl2(aq) + H2O(l) + CO2(g); ΔrH° = –15.2 kJ/mol-rxn

Hydrazine, N2H4, is a liquid used as a rocket fuel. It reacts with oxygen to yield nitrogen gas and water. N2H4() + O2(g) → N2(g) + 2 H2O() The reaction of 6.50 g N2H4 evolves 126.2 kJ of heat. Calculate the enthalpy change per mole of hydrazine combusted.

Which of the following thermodynamic quantities are state functions: heat (q), work (w), enthalpy change (ΔH), and/or internal energy change (ΔU)?

What is the energy per mole of photons of light with a wavelength of 690.8 nm?