c. Density of water=1 g/mL
So volume of 100 g water=mass/density=100 g/1 g/mL=100 mL=100 mL/1000 mL/L=0.1 L (1000 mL=1 L)
Molar mass of CaF2=Molar mass of Ca+2xmolar mass of F=40 g/mol+2x19 g/mol=40 g/mol+38 g/mol=78 g/mol
Number of moles of CaF2=mass/molar mass=10 g/78 g/mol=0.13 mol
Molarity of CaF2=number of moles/volume of solution (L)
=0.13 mol/0.1 L=0.013 M
CaF2 dissociates as shown in the solution
0.013 M 2x0.013 M
=0.026 M
Reaction quotient Q==0.013 M x (0.026 M)2=8.8x10-6 M3
As Q>Ksp so CaF2 will precipitate out. Qualitatively, 10 g Calcium fluoride added to 100 g water doesn't dissolve completely.
d. Since enthalpy of dissolution is positive, it means it is an endothermic reaction. On lowering the temperature of an endothermic reaction it moves in a direction so as to increase the temperature i.e. in backward direction. So lowering the temperature reduces the solubility of calcium fluoride and hence lowers its Ksp.
e. Number of moles of calcium nitrate=Molarity x Volume
=0.010 M x 100 mL/1000 mL/L
=0.001 mol
Concentration of calcium nitrate in diluted solution=number of moles/volume of the solution=0.001 mol/200 mL/1000 mL/L=0.005 M
1 molecule of CaF2 gives 1 Ca+2 in solution
So concentration of Ca+2 in solution=0.005 M
Number of moles of sodium fluoride=Molarity x Volume
=0.0010 M x 100 mL/1000 mL/L
=0.0001 mol
Concentration of NaF in diluted solution=number of moles/Volume (L)
=0.0001 mol/200 mL/1000 mL/L=0.0005 M
1 molecule of NaF gives 1 F- in solution
So concentration of F- in diluted solution=0.0005 M
Reaction quotient Q==0.005 M x (0.0005 M)2=1.25x10-9 M3
As Q>Ksp, a precipitate of calcium fluoride will form.
f. In CaF2, we have ionic bonding between Ca+2 (bivalent cation) and F-. In NaF the ionic bonding is between Na+ (monovalent cation) and F-. So the electrostatic forces of attraction is more in CaF2 than in NaF due to higher charge on calcium ion than sodium ion. So lattice energy is higher for calcium fluoride than NaF.
C. Consider the dissolution of CaF2 in water. The Ksp of CaF2 is 1.5 x 1010 at 25°C Qualitatively...
Calcium fluoride, CaF2, is an insoluble salt (Ksp = 1.46 x 10-10) that can be formed by precipitation by mixing solutions of calcium nitrate and sodium fluoride. Suppose 200.0 mL of a 0.600 M Ca(NO3)2(aq) solution are mixed with 400.0 mL of a 0.0600 M NaF(aq) solution. Will a precipitate form? How much calcium fluoride could form?
9) What is the gram solubility of CaF2 in 100.0 mL of pure water at 25 degree C. The solubility product constant of CaF2 is 3.9*10^-11. The molar mass is 78.1 g/mol.
MI Review | Constants 1 Periodi Consider the dissolution of AgBr in water at 25 'C: AgBr(s) = Ag+ (aq) + Br-(aq) Part B Substance AH' S and State kJ/mol J/(K.mol) Ag' (aq) 105.6 72.7 Br (aq) –121.5 82.4 AgBr(s) -100.4 107.1 Calculate Ksp for AgBr at 25°C. Express your answer to two significant figures. VA ALQ O 2 ? KE Submit Request Answer Part C Calculate AG for the dissolution of AgBr at 25°C when [Ag+] = [Br") –...
5 questions please show work Oxalic acid, H.C.O is a diprotic acid. What is the pH of a 0.100 M solution of oxalic acid, pk. - 1.25 pk = 4.14. Hard water contains a relatively high concentration of multivalent ions. A common ion found in hard water is Capt, and one of the sources is Caso.. What is the Ksp of calcium sulfate if the molar solubility of CaSO, is 0.0030 M? The solubility of CaF2 in pure water at...
Calculate the solubility at 25 °C of CaF2 in pure water and in a 0.0060 M NaF solution. You'll find K. data in the ALEKS Data tab. Round both of your answers to 2 significant digits. solubility in pure water: solubility in 0.0060 M Naf solution: x 6 ?
16.41 g of MgSO₄ is placed into 100.0 mL of water. The water's temperature increases by 6.7°C. Calculate ∆H, in kJ/mol, for the dissolution of MgSO₄. (The specific heat of water is 4.18 J/g・°C and the density of the water is 1.00 g/mL). You can assume that the specific heat of the solution is the same as that of water.
Question 29 of 50 Submit 5.21 g of MgSO4 is placed into 100.0 mL of water. The water's temperature increases by 6.70°C. Calculate AH, in kJ/mol, for the dissolution of MgSO4 (The spe- cific heat of water is 4.18 J/g. *C and the density of the water is 1.00 g/mL). You can assume that the specific heat of the solution is the same as that of water. kJ/mol 1 2 3 C +/- : 0 x 100
For CaF2 Kap = 3.9 x 10-" (molar mass = 78 g mol-') at 25°C. How many grams of this salt can be dissolved in 100 mL water at 25°C? (A) 0.8 mg (B) 1.2 mg (C) 1.7 mg (D) 2.0 mg (E) 2.4 mg
What is the final temperature of the solution when 4.806 g of sodium hydroxide is dissolved in 100.0 mL of water at an initial temperature of 24.5 C?. The density of water is 0.9969 g/cm3, and the heat capacity is 4.184 J/C. The enthalpy of dissolution for sodium hydroxide is -44.2 kJ/mol.
The Ksp of AgCl at 25 °C is 1.6 x 10-10. Consider a solution that is 1.0 x 10-2 M in CaCl2 and 1.0 x 10-8 M in AgNO3. A. Q> Ksp and a precipitate will form. B.Q> Ksp and a precipitate will not form. OC.Q<Ksp and a precipitate will not form. D.Q<Ksp and a precipitate will form. E. The solution is saturated.