If the Ka of a monoprotic weak acid is 5.4 × 10-6, what is the pH of a 0.25 M solution of this acid?
Answers
HA ---> H^+ + A^-
initial 0.25 0 0
change -x x x
equilibrium 0.25-x x x
This gives an expression for Ka given by:
Ka = (x)^2/(0.25-x) = 5.4x10^-6
x = 1.159x10^-3 = [H+] = [A-]
pH = -log[H+] = -log[1.159x10^-3] = 2.936
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Answers
Answer:
Rubidium (Rb)
Explanation:
Ionization Energy is defined as, "the minimum energy required to knock out or remove the valence electron from valence shell of an atom".
Trends in Periodic table:
Along Periods:
Ionization Energy increases from left to right along the periods because moving from left to right in the same period the number of protons (atomic number) increases but the number of shells remain constant hence, resulting in strong nuclear interactions and electrons are more attracted to nucleus hence, requires more energy to knock them out.
Along Groups:
Ionization energy decreases from top to bottom along the groups because the number of shells increases and the distance between nucleus and valence electrons also increases along with increase in shielding effect provided by core electrons. Therefore, the valence electrons experience less nuclear attraction and are easily removed.
Conclusion:
Given elements belong to same group hence, Rubidium present at the bottom of remaining elements will have least ionization energy due to facts explained in trends of groups above.
Answers
Answers
To solve this we must be knowing each and every concept related to Enthalpy. Therefore, 10,148KJ/mol is the ΔH for formation for the reaction 16CO(g) + 18H
O(g)
2C
H
(l) + 25O
(g)
What is Enthalpy?
Enthalpy term is basically used in thermodynamics to show the overall energy that a matter have. Mathematically, Enthalpy is directly proportional to specific heat capacity of a substances. Specific heat capacity of a substance is the amount of heat required to raise the temperature by one degree Celsius of one gram of a substance.
The balanced equation for the given chemical reaction can be given as
16CO(g) + 18H
O(g)
2C
H
(l) + 25O
(g)
ΔH for formation= 10,148KJ/mol
Therefore, 10,148KJ/mol is the ΔH for formation for the reaction 16CO(g) + 18H
O(g)
2C
H
(l) + 25O
(g)
To know more about enthalpy, here:
#SPJ2
Answer:
10,148
Explanation:
B)farm land
C)highways
D)public transportation
Answers
Answer: Option (A) is the correct answer.
Explanation:
An urban area is an area which is developed and it is a place where people can get almost all the things of their need easily.
Therefore, more an more people would like to live in an urban area as there will be more resources which can make people's work easy.
Hence, we can conclude that out of the given options an urban area is characterized by a dense human population.
Answers
Given:
25.0mL NaOH17.4 mL of a 0.132M HCL
Required:
molarity of NaOH
Solution:
M1V1 = M2V2
(25.0mL) M1 = (0.132 M HCl)( 17.4 mL)
M1 = 0.092 M NaOH
V1 = 0.5 liters
b. .78 M
c. 3.85 M
b. 4.98 M
Answers
Answer:
The correct answer is c.
Explanation:
First, look for the same problem to verify that the correct volume is 0.702 L.
Now we must calculate the amount of glucose moles (n) in the 500g:
n =
n = 2,7 mol
Molarity is given by moles of compound per liter. In this way, we calculate the molarity (M) as:
M =
M =
Have a nice day!
500 / 180.16 => 2.775 moles
Volume = 0.72 L
M = n / V
M = 2.775 / 0.72
M = 3.85 M
hope this helps!