Final answer:
To calculate the molarity of zinc cation, details such as the mass of zinc used and the volume of the solution are required. The concentration in the example with zinc hydroxide and added NaOH can be straightforwardly calculated with provided data. A common ion present can reduce the zinc ion concentration due to the common ion effect.
Step-by-step explanation:
To calculate the final molarity of zinc cation in the solution, we need to consider the mass of zinc and the volume of the solution it is dissolved in. From the information given about the molar masses of Zn and Zn(NO3)2, we can calculate the amount of Zn needed for a reaction, the theoretical yield, and then by comparing with the actual yield, we can determine the percent yield. However, to calculate the exact concentration of zinc ions, additional data such as the volume of the solution would be necessary. The example regarding the concentration of zinc ion in a saturated solution of zinc hydroxide with added NaOH gives a situation where the molarity can be directly calculated if we consider the given volume of the solution. In general, the concentration of zinc ions in a solution is expressed in moles per liter (M or mol/L).
Additionally, if a common ion like hydroxide is present in excess, it can affect the solubility of a compound like zinc hydroxide, reducing the concentration of the zinc ions as a result of the common ion effect. This relationship can be expressed using variables like 's' to represent the molar solubility in the presence of a common ion. A concentration cell example also involves the understanding of concentrations of zinc ions at equilibrium but does not provide sufficient data to calculate the molarity in this specific scenario