When 50.0 ml of a 0.3000 m agno3 solution is added to 50.0 ml of a solution of mgcl2, an agcl precipitate forms immediately. the precipitate is then filtered from the solution, dried, and weighed. if the recovered agcl is found to have a mass of 0.1183 g, what as the concentration of magnesium ions in the original mgcl2 solution?

Explanation:

The balanced reaction is:

We know, number of moles =

Therefore, moles of AgCl formed=        ( Molar mass of AgCl is 143 gm)

From the balanced equation 1 mol of forms 2 mol of AgCl.

Therefore, 0.000827 mol of AgCl was formed by

Now concentration of

Hence, this is the required solution.

answer: i would say b.

explanation:

assuming that your periodic table has eighteen columns, you should highlight   the four elements in the third column from the left of the table.

neutral atoms of elements after calcium contain d electrons. the energy of d orbitals of a particular main shell lies between the energy of the s and p orbitals of the next main shell. for example, electrons in the have energy higher than those in the orbital while lower than those of the orbital.

by the aufbau principle, electrons fill orbitals one at a time, starting from those of the lowest energy. the orbital is therefore filled right after orbitals and before orbitals.  

potassium has electron configuration and calcium . the s orbital of a main shell holds a maximum of two electrons. the next element would thus have the electron configuration and satisfy the requirements.

a neutral atom of the element contains three electrons on top of the most recent noble gas element. it should thus be placed in the third column of the periodic table. both scandium and yttrium would satisfy the conditions. an aufbau diagram indicates that the 4f orbital is filled before the 5d. however, it appears that exceptions exists for both lanthanum and actinium. neutral atoms of the two d-block elements also demonstrate the and should be highlighted as well.