Calculate the concentrations of Al^-2 and SO_4^-3 in an aqueous solution prepare

Question

Calculate the concentrations of Al^-2 and SO_4^-3 in an aqueous solution prepared by dissolving 17.1 g Al_2(SO_4)_3 in enough water to make 400. mL of solution. Calculate the concentrations of Ba^+ and SI_i^-2 an aqueous solution prepared by dissolving 852 g Na_2SO_4 in enough water to make 400 L of solution. what mass (in g) of CaCl_2 is needed to prepare 100.0 mL of an aqueous solution that is 0.25 M in Cl_2? If 100.0 mL of 18 M H_2SO_4 solution are diluted to 10.0 L, what are concentrations of H^+ and SO_4^-2 in the diluted solution?

Explanation / Answer

7)

We are given the number of grams of solute (852 g), its chemical formula (Na2SO4), and the volume of the solution (4000 mL) and asked to calculate the molarity of the solution. Our plan is to use the definition of molarity, Equation 4.34:

molarity = mole of Na2SO4/ litre solution

The number of moles of Na2SO4 is obtained using its molar mass:

moles of Na2SO4 = 852(1 mols Na2SO4/142 g Na2SO4)

moles of Na2SO4 =6 mole moles of Na2SO4

The volume of the solution must be expressed in liters:

Thus, the molarity is

molarity = mole of Na2SO4/ litre solution

= 6/4

molarity =1.5 M

8)

Moles CaCl2 required = 0.100 L x 0.25 = 0.4
Molar mass = 110.984 g/mol
Mass = 0.4 mol x 110.984 g/mol = 44.39 g

9)

  M1 x v1=M2 x v2
18.0 x 0.1L=M2 x 10L
1.8= M2 x 10
M2=1.8/10
M2=0.18M
M2 is the concentration of H2SO4 after diluted..
H2SO4--->2H+ +SO4^2-
[H+]=2 x [H2SO4]= 0.36M
[SO4^2-]=1 x [H2SO4]=0.18M

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.