Multiply the following: (1.25 x 10^15) x (3.75 x 10^5).

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

Which of the following statements about material bonding is correct? C O a. Ionic bonds are formed by the sharing of valence ele

Zina [86]

Answer: Option (b) is the correct answer.

Explanation:

In material bonding, there occurs Vander waal foces between the molecules in which their is either an induced or permanent dipole moment that attract molecules towards each other.

And, due to these forces the molecules are held together.

On the other hand, in a ionic bond there will always be transfer of electrons from one atom to another. This is because on atom which loses its valence electrons acquires a positive charge and another atom which gains the electrons acquires a negative charge.

Hence, these opposite charges strongly gets attracted towards each other forming a strong bond.

Whereas in a covalent bond, there will be sharing of electrons between the combining atoms.

In a metallic bond, there occurs a sea of electrons which is uniformly distributed throughout the solid substance or material.

Thus, we can conclude that the statement, Van der Waals bonds are formed by Van der Waals forces in which molecules or atoms have either an induced or permanent dipole moment to attract each other, about material bonding is correct.

5 0

4 years ago

Giselle is working with a chemical substance in a laboratory. She observes that when the chemical is heated, it gives off a gas.

Phoenix [80]

The correct answer is option B, that is, hypothesis.

A hypothesis refers to an anticipated illustration for an occurrence. It refers to a proposed illustration or a supposition made on the groundwork of inadequate proof as an initiation point for further investigation. In order for a hypothesis to be a scientific hypothesis, the scientific method needs that one can examine it.

6 0

3 years ago

Read 2 more answers

How many mL of 2M stock solution would I use to prepare 0.500 L of 0.1 M NaCl?

nordsb [41]

Answer:

25 mL

Explanation:

Step 1: Given data

Concentration of the concentrated solution (C₁): 2 M

Volume of the concentrated solution (V₁): ?

Concentration of the diluted solution (C₂): 0.1 M

Volume of the diluted solution (V₂): 0.500 L

Step 2: Calculate the volume of the concentrated NaCl solution

We will use the dilution rule.

C₁ × V₁ = C₂ × V₂

V₁ = C₂ × V₂ / C₁

V₁ = 0.1 M × 0.500 L / 2 M

V₁ = 0.025 L = 25 mL

4 0

3 years ago

A metallic conductor moving at a constant speed in a magnetic field may develop a voltage across it. this is an example of _____

marysya [2.9K]

A metallic conductor moving at a constant speed in a magnetic field may develop a voltage across it. This is an example of Motional emf
Hope this helps!

3 0

4 years ago