Question: How many grams of Milk of Magnesia, \(Mg{(OH)_2}(s)(58.3g/mol)\)would be soluble in 200 mL of water. \({K_{sp}}\)=\(7.1 \times 1{0^{ - 12}}\) Include the ionic reaction and the expression for \({K_{sp}}\)in your answer\(\left( {{K_w} = 1 \times 1{0^{ - 14}} = } \right.\)\(\left. {\left( {{H_3}{O^ + }} \right)\left( {O{H^ - }} \right)} \right)\)

Short Answer

Expert verified

There is \(1.14 \times {10^{ - 3}}{\rm{g}}\)of milk of magnesia.

Step by step solution

01

Calculate grams of Milk of Magnesia:

\(Mg{(OH)_2}(s) \leftrightarrow M{g^{2 + }} + 2O{H^ - }\)

Find \({K_{{\rm{sp}}}}\),

\(\begin{array}{l}{K_{sp}} = \left( {M{g^{2 + }}} \right){\left( {O{H^ - }} \right)^2}\\ = 7.1 \times {10^{ - 12}}\end{array}\)

\(\begin{array}{l}\left( {M{g^{2 + }}} \right) = \sqrt(3){{\frac{{{K_{sp}}}}{4}}}\\ = \sqrt(3){{\frac{{7.1 \times {{10}^{ - 12}}}}{4}}}\\ = 1.21 \times {10^{ - 4}}M\end{array}\)

\(\begin{array}{l}m\left( {Mg{{(OH)}_2}} \right) = c\left( {M{g^{2 + }}} \right) \times V\left( {{H_2}O} \right) \times {M_r}\left( {Mg{{(OH)}_2}} \right)\\ = 1.21 \times {10^{ - 4}}M \times 0.2L \times 58.3g/mol\\ = 1.14 \times {10^{ - 3}}g\end{array}\)

The solution is \(1.14 \times {10^{ - 3}}{\rm{g}}\)of milk of magnesia.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

A volume of \(50mL\) of \(1.8MN{H_3}\)is mixed with an equal volume of a solution containing\(0.95g\;of\;MgC{l_2}\). What mass of \(N{H_4}Cl\)must be added to the resulting solution to prevent the precipitation of \(Mg{(OH)_2}?\)

Assuming that no equilibria other than dissolution are involved, calculate the concentration of all solute species in each of the following solutions of salts in contact with a solution containing a common ion. Show that changes in the initial concentrations of the common ions can be neglected.

\(\begin{array}{l}(a)AgCl(\;s\;)in 0.025MNaCl \\(b)Ca{F_2}(\;\;s\;)in 0.00133MKF \\(c)A{g_2}S{O_4}(\;\;s\;)in 0.500\;L of a solution containing 19.50\;g of {K_2}S{O_4}\\(d)Zn{(OH)_2}(\;s\;)in a solution buffere data pHof 11.45\end{array}\)

Complete the changes in concentrations for each of the following reactions:

\(\begin{array}{l}(a)BaS{O_4}(S) \to nB{a^{2 + }}(aq) + SO_4^{2 - }(aq)\\ X - \\(b)A{g_2}S{O_4}(S) \to n2A{g^ + }(aq) + S{O_4}^{2 - }(a)\\ - X\\(c)Al{(OH)_3}(S) \to nA{l^{3 + }}(aq) + 3O{H^ - }(aq)\\ X \_ \\(d)Pb(OH)Cl(S) \to nP{b^{2 + }}(aq) + O{H^ - }(aq) + C{l^ - }(aq)\\ \_ X \_\\(e)C{a_3}{\left( {As{O_4}} \right)_2}(S) \to n3C{a^{2 + }}(aq) + 2AsO_4^{3 - }(aq)\\ 3x \_\end{array}\)

The following question is taken from a Chemistry Advanced Placement Examination and is used with the permission of the Educational Testing Service. Solve the following problem:

MgF2 (S) ⇌ Mg2+(aq) + 2F- (aq)

In a saturated solution of MgF2 at 18 °C, the concentration ofMg2+is 1.21×10-3 M.

The equilibrium is represented by the preceding equation.

(a) Write the expression for the solubility-product constant, Ksp, and calculate its value at 18 °C.

(b) Calculate the equilibrium concentration of Mg2+ in 1.000 L of saturated MgF2solution at 18 °C to which 0.100 mol of solid KF has been added. The KF dissolves completely. Assume the volume change is negligible.

(c) Predict whether a precipitate of MgF­2 will form whensolution of 100.0mL of a 3.00 ×10-3 -M Mg(NO3)2 is mixed with 200.0 mL of a 2.00 × 10–3 -M solution of NaF at 18 °C. Show the calculations to support your prediction.

(d) At 27 °C the concentration of Mg2+ in a saturated solution of MgF2 is 1.17×10-3 M. Is the dissolving of MgF2 in water an endothermic or an exothermic process? Give an explanation to support your conclusion.

What is the molar solubility of \({\bf{Pb}}{\left( {{\bf{OH}}} \right)_{\bf{2}}}\) in a \({\bf{0}}.{\bf{138}}{\rm{ }}{\bf{M}}\) solution of\({\bf{C}}{{\bf{H}}_{\bf{3}}}{\bf{N}}{{\bf{H}}_{\bf{2}}}\)?

See all solutions

Recommended explanations on Chemistry Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free