A) F-F

Groundwater in Pherric, New Mexico, initially contains 1.800 mg/L of iron as Fe3+. What must the pH be raised to in order to pre

xenn [34]

Answer : The pH will be, 3.2

Explanation :

As we known that the value of solubility constant of ferric hydroxide at $25^oC$ is, $2.79\times 10^{-39}$

Amount or solubility of iron consumed = (1.800 - 0.3) mg/L = 1.5 mg/L

The given solubility of iron convert from mg/L to mol/L.

$1.5mg/L=\frac{1.5\times 10^{-3}g/L}{56g/mol}=2.7\times 10^{-7}mol/L$

The chemical reaction will be:

$Fe(OH)_3\rightarrow Fe^{3+}+3OH^-$

The expression of solubility constant will be:

$K_{sp}=[Fe^{3+}]\times [3OH^-]^3$

Now put all the given values in this expression, we get the concentration of hydroxide ion.

$2.79\times 10^{-39}=(2.7\times 10^{-7})\times [3OH^-]^3$

$[OH^-]=1.5\times 10^{-11}M$

Now we have to calculate the pOH.

$pOH=-\log [OH^-]$

$pOH=-\log (1.5\times 10^{-11})$

$pOH=10.8$

Now we have to calculate the pH.

$pH+pOH=14\\\\pH=14-pOH\\\\pH=14-10.8\\\\pH=3.2$

Therefore, the pH will be, 3.2

4 0

3 years ago

The ksp of pbi2 is 1.4 x 10-8. what is the molar solubility of lead(ii iodide in a solution of 0.400 m sodium iodide?

tino4ka555 [31]

The solubility product of a substance us calculated by the product of the concentration of the dissociated ions in the solution raise to the stoichiometric coefficient of the ions. Therefore, we need the dissociation reaction. For this, it will have the reaction:

PbI2 = Pb^2+ + 2I-

We solve as follows:

Ksp = [Pb2+][I-]^2 = 1.4 x 10-8
1.4 x 10-8 = x(2x)^2
1.4 x 10-8 = 4x^3
x = 1.5x10^-3 M

The molar solubility would be 1.5x10^-3 M.

8 0

2 years ago

Biomes are defined by specific characteristics. What characteristics would define the biome shown? a. cool and windy with coarse

KIM [24]

Answer : Option D) Hot and dry with low growing shrubs.

Explanation : According to the attached image of the Biome, this particular biome displays the hot and dry climatic region along with low growing shrubs. A biomes are the way to divide the largely occurring flora and fauna in a particular place on the Earth's surface. These divisions are made on the basis of climatic patterns, soil types, and the animals and plants that are found to inhabit in that area.

4 0

3 years ago

Read 2 more answers

An abandoned Indiana coal mine spoil bank (wastes) contains chunks of pyrite minerals. Under constant erosion and weathering, th

Minchanka [31]

Answer:

The acid will be neutralized overtime

Explanation:

The presence of the pyrites leads to the leaching of large amounts of sulphuric acid, however the basic carbonates neutralizes the acid according to the reaction equation;

CaCO3 + H2SO4 ---> CaSO4 + CO2 + H2O.

This will prevent all the deleterious consequences associated with the leaching of the acid in the abandoned coal mine.

7 0

3 years ago

Why are stars special sources of light?(2 points)

Alex787 [66]

Answer:

They give off their own light energy

Explanation:

I'm taking astronomy and I answered this questions not too long ago

8 0

2 years ago