If an ion has a -2 charge, how many extra electrons do you add to the lewis structure

Achemistry student weighs out 0.306 g of citric acid (h3c6h5o7), a triprotic acid, into a 250 ml volumetric flask and dilutes to the mark with distilled water. he plans to titrate the acid with 0.1000 m naoh solution. calculate the volume of naoh solution the student will need to add to reach the final equivalence point. be sure your answer has the correct number of significant digits.

How does concentration affect reaction rate

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