The answer for this question is D.
Complete Question
You determine that it takes 26.0 mL of base to neutralize a sample of your unknown acid solution. The pH of the solution was 7.82 when exactly 13 mL of base had been added, you notice that the concentration of the unknown acid was 0.1 M. What is the pKa of your unknown acid?
Answer:
The pK_a value is
Explanation:
From the question we are told
The volume of base is
The pH of solution is
The concentration of the acid is
From the pH we can see that the titration is between a strong base and a weak acid
Let assume that the the volume of acid is
Generally the concentration of base
Substituting value
When 13mL of the base is added a buffer is formed
The chemical equation of the reaction is
Now before the reaction the number of mole of base is
Substituting value
Now before the reaction the number of mole of acid is
Substituting value
Now after the reaction the number of moles of base is zero i.e has been used up
this mathematically represented as
The number of moles of acid is
The pH of this reaction can be mathematically represented as
Substituting values
Answer:
D. Surface tension.
Explanation:
Surface tension is defined as the energy required to increase the surface area of a liquid by a unit amount.
The surface tension of a liquid results from an imbalance of intermolecular attractive forces, the cohesive forces between molecules:
A molecule in a liquid experiences cohesive forces with other molecules in all directions while molecules at the surface of a liquid experiences only net inward cohesive forces.
<h3>Balanced equation :
2C₂H₆ (g) + 7O₂ (g) ⟶ 4CO₂ (g) + 6H₂O (ℓ)</h3><h3>Further explanation</h3>
Alkanes are saturated hydrocarbons that have single bonds in chains
General formula for alkanes :
Hydrocarbon combustion reactions (specifically alkanes)
So that the burning of ethane with air (oxygen):
2C₂H₆ (g) + 7O₂ (g) ⟶ 4CO₂ (g) + 6H₂O (ℓ)
or we can use mathematical equations to solve equilibrium chemical equations by giving the coefficients for each compound involved in the reaction
C₂H₆ (g) + aO₂ (g) ⟶ bCO₂ (g) + cH₂O (ℓ)
C : left 2, right b ⇒ b=2
H: left 6, right 2c⇒ 2c=6⇒ c= 3
O : left 2a, right 2b+c⇒ 2a=2b+c⇒2a=2.2+3⇒2a=7⇒a=7/2
Answer:
The answer to your question is below
Explanation:
1. Found in period 2. All the elements in the list are found in period 2.
a. F This option is correct
b. Be Beryllium is located in period two.
c. O also oxygen is found in period 2.
d. C Carbon is found in period 2.
2.- Can gain lose 4 electrons to become its nearest stable noble gas. Only Carbon.
a. F This option is wrong, F becomes stable when it gains 1 electron.
b. Be Beryllium becomes stable when it loses 2 electrons.
c. O Become stable when it gains 2 electrons.
<u>d. C </u><u>Become stable when it gains or loses 4 electrons.</u>