What is a common use of bases?

BH+ClO4- is a salt formed from the base B (Kb = 1.00e-4) and perchloric acid. It dissociates into BH+, a weak acid, and ClO4-, w

Len [333]

Answer:

The pH of 0.1 M BH⁺ClO₄⁻ solution is 5.44

Explanation:

Given: The base dissociation constant: $K_{b}$ = 1 × 10⁻⁴, Concentration of salt: BH⁺ClO₄⁻ = 0.1 M

Also, water dissociation constant: $K_{w}$ = 1 × 10⁻¹⁴

The acid dissociation constant ( $K_{a}$ ) for the weak acid (BH⁺) can be calculated by the equation:

$K_{a}. K_{b} = K_{w}$

$\Rightarrow K_{a} = \frac{K_{w}}{K_{b}}$

$\Rightarrow K_{a} = \frac{1\times 10^{-14}}{1\times 10^{-4}} = 1\times 10^{-10}$

Now, the acid dissociation reaction for the weak acid (BH⁺) and the initial concentration and concentration at equilibrium is given as:

Reaction involved: BH⁺ + H₂O ⇌ B + H₃O+

Initial: 0.1 M x x

Change: -x +x +x

Equilibrium: 0.1 - x x x

The acid dissociation constant: $K_{a} = \frac{\left [B \right ] \left [H_{3}O^{+}\right ]}{\left [BH^{+} \right ]} = \frac{(x)(x)}{(0.1 - x)} = \frac{x^{2}}{0.1 - x}$

$\Rightarrow K_{a} = \frac{x^{2}}{0.1 - x}$

$\Rightarrow 1\times 10^{-10} = \frac{x^{2}}{0.1 - x}$

$As, x$

$\Rightarrow 0.1 - x = 0.1$

$\therefore 1\times 10^{-10} = \frac{x^{2}}{0.1 }$

$\Rightarrow x^{2} = (1\times 10^{-10})\times 0.1 = 1\times 10^{-11}$

$\Rightarrow x = \sqrt{1\times 10^{-11}} = 3.16 \times 10^{-6}$

Therefore, the concentration of hydrogen ion: x = 3.6 × 10⁻⁶ M

Now, pH = - ㏒ [H⁺] = - ㏒ (3.6 × 10⁻⁶ M) = 5.44

Therefore, the pH of 0.1 M BH⁺ClO₄⁻ solution is 5.44

5 0

2 years ago

Consider a generic redox reaction?

vesna_86 [32]

The Nernst equation allows us to predict the cell potential for voltaic cells under conditions other than the standard conditions of 1M, 1 atm, 25°C. The effects of different temperatures and concentrations may be tracked in terms of the Gibbs energy change ΔG. This free energy change depends upon the temperature & concentrations according to ΔG = ΔG° + RTInQ where ΔG° is the free energy change under conditions and Q is the thermodynamic reaction quotient. The free energy change is related to the cell potential Ecell by ΔG= nFEcell

so for non-standard conditions
-nFEcell = -nFE°cell + RT InQ

or

Ecell = E°cell - RT/nF (InQ)

which is called Nernst equation.

5 0

2 years ago

Determine how many liters of hydrogen adjusted to STP there are in a 50.0 liter steel cylinder if the pressure inside is 100.0 a

Dvinal [7]

Answer : The volume of hydrogen gas at STP is 4550 L.

Explanation :

Combined gas law is the combination of Boyle's law, Charles's law and Gay-Lussac's law.

The combined gas equation is,

$\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}$

where,

$P_1$ = initial pressure of gas = 100.0 atm

$P_2$ = final pressure of gas at STP = 1 atm

$V_1$ = initial volume of gas = 50.0 L

$V_2$ = final volume of gas at STP = ?

$T_1$ = initial temperature of gas = $27.0^oC=273+27.0=300K$

$T_2$ = final temperature of gas at STP = $0^oC=273+0=273K$

Now put all the given values in the above equation, we get:

$\frac{100.0atm\times 50.0L}{300K}=\frac{1atm\times V_2}{273K}$

$V_2=4550L$

Therefore, the volume of hydrogen gas at STP is 4550 L.

3 0

3 years ago

Which principle goes against Bohr's theory and why??

Basile [38]

Answer:

As the Bohr's fixed orbit gives precise information about the radial position and momentum of the orbit, it is against the Heisenberg uncertainty principle. Thus it is inferred that the Heisenberg uncertainty principle goes and the concept Bohr's fixed Orbit are opposite to each other.

Explanation:

7 0

2 years ago

The half-life of a strontium isotope is 25 years. How much of this particular isotope will remain after 100 years if the startin

Phoenix [80]

Answer:

1 gram

Explanation:

Half life = 25 years

Starting mass = 16 grams

Time = 100 years

Number of half lives = Time / Duration of Half life = 100 / 25 = 4

After first Half life;

Remaining mass = 16 / 2 = 8 g

After Second Half life;

Remaining mass = 8 / 2 = 4 g

After Third Half life;

Remaining mass = 4 / 2 = 2 g

After Fourth Half life;

Remaining mass = 2 / 2 = 1 g

3 0

2 years ago