What does the activity series tell us ?

(2 pts) The solubility of InF3 is 4.0 x 10-2 g/100 mL. a) What is the Ksp? Include the chemical equation and Ksp expression. MW

Aleonysh [2.5K]

Answer:

a) Ksp = 7.9x10⁻¹⁰

b) Solubility is 6.31x10⁻⁶M

Explanation:

a) InF₃ in water produce:

InF₃ ⇄ In⁺³ + 3F⁻

And Ksp is defined as:

Ksp = [In⁺³] [F⁻]³

4.0x10⁻²g / 100mL of InF₃ are:

4.0x10⁻²g / 100mL ₓ (1mol / 172g) ₓ (100mL / 0.1L) = 2.3x10⁻³M InF₃. Thus:

[In⁺³] = 2.3x10⁻³M InF₃ × (1 mol In⁺³ / mol InF₃) = 2.3x10⁻³M In⁺³

[F⁻] = 2.3x10⁻³M InF₃ × (3 mol F⁻ / mol InF₃) = 7.0x10⁻³M F⁻

Replacing these values in Ksp formula:

Ksp = [2.3x10⁻³M In⁺³] × [7.0x10⁻³M F⁻]³ = 7.9x10⁻¹⁰

b) 0.05 moles of F⁻ produce solubility of InF₃ decrease to:

7.9x10⁻¹⁰ = [x] [0.05 + 3x]³

Where x are moles of In⁺³ produced from solid InF₃ and 3x are moles of F⁻ produced from the same source. That means x is solubility in mol / L

Solving from x:

x = -0.018 → False solution, there is no negative concentrations.

x = 6.31x10⁻⁶M → Right answer.

Thus, solubility is 6.31x10⁻⁶M

3 0

3 years ago

A sample of oxygen occupies 47.2 liters under a pressure of 1240 torr at 298K. What volume would it occupy at 303K if the pressu

kupik [55]

Answer:

81.5 L

Explanation:

We can use the combined gas law equation that gives the relationship among pressure, temperature and volume of gases for a fixed amount of gas.

P1V1 / T1 = P2V2 / T2

where P1 - pressure, V1 - volume and T1 - temperature at the first instance

P2 - pressure, V2 - volume and T2 - temperature at the second instance

substituting the values in the equation

1240 Torr x 47.2 L / 298 K = 730 Torr x V2 / 303 K

V2 = 81.5 L

the new volume the gas would occupy when the conditions have changed is 81.5 L

3 0

3 years ago

You need to prepare 100.0 mL of a pH 4.00 buffer solution using 0.100 M benzoic acid (p K a = 4.20 ) and 0.200 M sodium benzoate

bekas [8.4K]

Answer : The volume of sodium benzoate and benzoic acid solution mixed to prepare this buffer should be, 29.0 mL and 71 mL respectively.

Explanation :

Let the volume of sodium benzoate (salt) be, x

So, the volume of benzoic acid (acid) will be, (100 - x)

Using Henderson Hesselbach equation :

$pH=pK_a+\log \frac{[Salt]}{[Acid]}$

Now put all the given values in this expression, we get:

$4.00=4.20+\log \left(\frac{(\frac{0.200x}{100})}{(\frac{0.100(100-x)}{100})}\right)$

x = 29.0

The volume of sodium benzoate = x = 29.0 mL

The volume of benzoic acid (acid) = (100 - x) = (100 - 29.0) = 71 mL

Thus, the volume of sodium benzoate and benzoic acid solution mixed to prepare this buffer should be, 29.0 mL and 71 mL respectively.

5 0

3 years ago

Explain hybridization and bond angles of following compounds using VBT

natima [27]

Apples and bananas guys apples and bananas

5 0

3 years ago

Explain why calcium metal after reacting with water starts floating on its surface. Write the chemical equation for this reactio

Oksanka [162]

Firstly, the chemical equation between the calcium metal and water will be:

Ca(s) + 2 H₂O(l) → Ca(OH)₂(aq) + H₂(g)

We can see from the equation the bubbles of hydrogen gas which are formed during the reaction stick to the surface of the metal and hence calcium floats on water.

The other metal that will float on the water during the reaction is magnesium which have the same chemical behavior like calcium, we can illustrate that by the chemical equation:

Mg(s) + 2 H₂O(l) → Mg(OH)₂(aq) + H₂(g)

3 0

3 years ago