4. What is the enthalpy change (H°) for the reaction 4NaCl(s) → 4Na(s) + 2Cl2(g), if the reaction 2Na(s) + Cl2(g) → 2NaCl(s) has H° = -821.8 kJ?

Achemistry student weighs out of phosphoric acid , a triprotic acid, into a volumetric flask and dilutes to the mark with distilled water. he plans to titrate the acid with solution. calculate the volume of solution the student will need to add to reach the final equivalence point. round your answer to significant digits.

Determine the wavelength of the light absorbed when an electron in a hydrogen atom makes a transition from an orbital in the n=3 level to an orbital in the n=7 level.

An atomic nucleus is composed ofa)protons. b)protons and neutrons. c)protons and electrons. d)protons, neutrons, and electrons.