The pH of a 0.30-M solution of a weak base is 10.66 at 25 o C . The K b of the given base has to be calculated. Concept Information: Strong base and weak base: Strong base dissociates into its constituent ions fully. It produces more of hydroxide ions while dissolved in water. Weak bases partially dissociates into its constituent ions. According to Bronsted-Lowry, strong base is a good proton acceptor whereas weak base is a poor proton acceptor Since, the ionization of a weak base is incomplete; it is treated in the same way as the ionization of a weak acid. The ionization of a weak base B is given by the below equation. B (aq) +H 2 O (l) → HB + (aq) +OH - (aq) The equilibrium expression for the ionization of weak base B will be, K b = [ HB + ] [ OH - ] [ B ] Where, K b is base ionization constant, [ OH − ] is concentration of hydroxide ion [ HB + ] is concentration of conjugate acid [ B] is concentration of the base pOH definition: The pOH of a solution is defined as the negative base-10 logarithm of the hydroxide ion [OH - ] concentration. pOH scale is analogous to pH scale. pOH = -log[OH - ] Relationship between pH and pOH pOH is similar to pH . The only difference is that in pOH the concentration of hydroxide ion is used as a scale while in pH , the concentration of hydronium ion is used. The relationship between the hydronium ion concentration and the hydroxide ion concentration is given by the equation, pH + pOH = 14, at 25 o C As pOH and pH are opposite scale, the total of both has to be equal to 14.
The pH of a 0.30-M solution of a weak base is 10.66 at 25 o C . The K b of the given base has to be calculated. Concept Information: Strong base and weak base: Strong base dissociates into its constituent ions fully. It produces more of hydroxide ions while dissolved in water. Weak bases partially dissociates into its constituent ions. According to Bronsted-Lowry, strong base is a good proton acceptor whereas weak base is a poor proton acceptor Since, the ionization of a weak base is incomplete; it is treated in the same way as the ionization of a weak acid. The ionization of a weak base B is given by the below equation. B (aq) +H 2 O (l) → HB + (aq) +OH - (aq) The equilibrium expression for the ionization of weak base B will be, K b = [ HB + ] [ OH - ] [ B ] Where, K b is base ionization constant, [ OH − ] is concentration of hydroxide ion [ HB + ] is concentration of conjugate acid [ B] is concentration of the base pOH definition: The pOH of a solution is defined as the negative base-10 logarithm of the hydroxide ion [OH - ] concentration. pOH scale is analogous to pH scale. pOH = -log[OH - ] Relationship between pH and pOH pOH is similar to pH . The only difference is that in pOH the concentration of hydroxide ion is used as a scale while in pH , the concentration of hydronium ion is used. The relationship between the hydronium ion concentration and the hydroxide ion concentration is given by the equation, pH + pOH = 14, at 25 o C As pOH and pH are opposite scale, the total of both has to be equal to 14.
The pH of a 0.30-M solution of a weak base is 10.66 at 25oC. The Kb of the given base has to be calculated.
Concept Information:
Strong base and weak base:
Strong base dissociates into its constituent ions fully. It produces more of hydroxide ions while dissolved in water. Weak bases partially dissociates into its constituent ions.
According to Bronsted-Lowry, strong base is a good proton acceptor whereas weak base is a poor proton acceptor
Since, the ionization of a weak base is incomplete; it is treated in the same way as the ionization of a weak acid.
The ionization of a weak base B is given by the below equation.
B(aq)+H2O(l)→HB+(aq)+OH-(aq)
The equilibrium expression for the ionization of weak base B will be,
Kb=[HB+][OH-][B]
Where,
Kb is base ionization constant,
[OH−] is concentration of hydroxide ion
[HB+] is concentration of conjugate acid
[B] is concentration of the base
pOH definition:
The pOH of a solution is defined as the negative base-10 logarithm of the hydroxide ion [OH-] concentration. pOH scale is analogous to pH scale.
pOH=-log[OH-]
Relationship between pH and pOH
pOH is similar to pH. The only difference is that in pOH the concentration of hydroxide ion is used as a scale while in pH, the concentration of hydronium ion is used.
The relationship between the hydronium ion concentration and the hydroxide ion concentration is given by the equation,
pH+pOH=14,at25oC
As pOH and pH are opposite scale, the total of both has to be equal to 14.
The representation of a one-dimensional velocity distribution function for a gas, as the temperature increases:a) it becomes more flattenedb) the maximum occurs for vi = 0 m/sExplain it.
The velocity distribution function of gas moleculesa) is used to measure their velocity, since the small size of gas molecules means that it cannot be measured in any other wayb) is only used to describe the velocity of particles if their density is very high.c) describes the probability that a gas particle has a velocity in a given interval of velocities
Explain why in the representation of a one-dimensional velocity distribution function for a particular gas, the maximum occurs for vi = 0 m/s.