Please help with this

H A and H B are both weak acids in water, and HA is a stronger acid than HB. Which of the following statements is correct? Selec

lubasha [3.4K]

Answer:

B is a stronger base than A^-, which is a stronger base than H2O, which is a stronger base than CI^-

Explanation:

The general equation for each acid is:

HA(aq) + H2O(ac) ⇄ H3O+(aq) + A-(aq)

HB(aq) + H2O(ac) ⇄ H3O+(aq) + B-(aq)

When these acids dissociate into its ions in water they lose a proton (H+), so they are proton donors (acids) and H2O is the proton acceptor (base). This reaction produces a conjugate acid and a conjugate base.

Conjugate base is what remains of the acid molecule after it loses a proton:

HA = acid A- Conjugate base

HB = acid B- Conjugate base

A conjugate acid is formed when the proton is transferred to the base

H2O = base H3O+ = Conjugate acid

The stronger acid will produce a weaker base. According to this, if HA is a stronger acid than HB, A- would be the weaker base (B- is the stronger base).

Compared with water, A- and B- are stronger bases because when they compete for a proton they have much greater affinity for H+ than water does and the equilibrium position will lie far to the left. (HA and HB are weak acids)

Finally Cl- is the weakest base because it comes after dissociation of HCl which is a strong acid

HCl(aq) + H2O → H3O+(aq) + Cl-(aq)

Note there is no double arrows, equilibrium lies far to the right. A strong acid yields a weak conjugate base it means one that has a low affinity for a proton.

4 0

3 years ago

Solid lead acetate is slowly added to 75.0 mL of a 0.0492 M sodium sulfate solution. What is the concentration of lead ion requi

Firdavs [7]

Answer:

The concentration of lead ion required to just initiate precipitation is - $2.37\times10^-^5 M$

Explanation:

Lets calculate -:

Solubility equilibrium -: $PbI_2(s)$ ⇄ $Pb^2^+ (aq) + 2I^- (aq)$

Solubility product of $PbI_2$ , $Q=[Pb^2^+]_i_n_i_t_i_a_l$ $[I^-]^2_i_n_i_t_i_a_l$ $=9.8\times10^-^9$

Concentration of $I^-$ $=[KI]=0.0492M$

When the ionic product exceeds the solubility product , precipitation of salt takes place .

$Q_s_p\geq K_s_p$

$[Pb^2^+]_i_n_i_t_i_a_l$ $[I^-]^2_i_n_i_t_i_a_l$ $\geq 9.8\times10^-^9$

$[Pb^2^+]_i_n_i_t_i_a_l$ $[0.0492]^2$ $\geq 9.8\times10^-^9$

$[Pb^2^+]_i_n_i_t_i_a_l$ $\geq \frac{9.8\times10^-^9}{[0.0492]^2}$

$[Pb^2^+]_i_n_i_t_i_a_l$ $\geq$ $\frac{9.8\times10^-^9}{2.42\times10^-^3}$

$[Pb^2^+]_i_n_i_t_i_a_l$ $\geq$ $2.37\times10^-^5 M$

Thus , $PbI_2$ will start precipitating when $[Pb^2^+]_i_n_i_t_i_a_l$ $\geq 2.37\times10^-^5 M$ .

3 0

3 years ago

When a liquid sample is taken from sea level to a higher elevation, what happens to the external (atmospheric) pressure on the l

BigorU [14]

Answer:

The external atmospheric pressure decreases and so does the boiling point of the liquid.

Explanation:

We know that pressure decreases with height. Thus atmospheric pressure decreases at higher elevation.

The implication of this is that, if I take a liquid from sea level to a higher elevation, the external atmospheric pressure on the liquid will decrease and so does its boiling point.

Hence, the liquid boils at a lower temperature when placed at a higher elevation. For this reason, the boiling point of a liquid is lower on the mountain.

5 0

3 years ago

There are many different types of objects in the solar system. Which type of object is the Sun?

Keith_Richards [23]

It is a star, since it glows and is very hot.

6 0

4 years ago

What is the best way to compare a concentrated solution to a dilute solution, given the same volume of solution?

jeka57 [31]

The correct answer is B. Given a same volume of a solution, the concentrated solution has more solute than the dilute solution. For instance, we are given two NaOH solutions having a volume of 1L one has a concentration of 1M and the other is 2M. The latter has more solute since it has 2 moles of NaOH while the other only has 1 mole.

7 0

3 years ago

Read 2 more answers