Se tiene una solución de HNO2 al 0,0045 M, ionizada al 3,53%. Determinar:  Concentración de los iones.  Concentración del HNO2.
 El pH de la solución.
Ka

If the atomic mass of an atom is 34 and the atom contains 13 protons, how many neutrons does the atom contain?

Which characteristics can be used to differentiate star systems? check all that apply.

Modern pennies are composed of zinc coated with copper. a student determines the mass of a penny to be 2.482 g and then makes several scratches in the copper coaling (to expose the underlying zinc). the student puts the scratched penny in hydrochloric acid, where the following reaction occurs between the zinc and the hcl (the copper remains undissolved): zn(s) + 2 hcl(aq) → h2(g) + zncl(aq)the student collects the hydrogen produced over water at 25 °c. the collected gas occupies a volume of 0.899 l at a total pressure of 79 j mmhg. calculate the percent zinc (by mass) in the penny. (assume that all the zn in the penny dissolves.)