All categories

1 year ago

A 0. 22 m aqueous solution of the weak acid ha at 25. 0 °C has a ph of 4. 15. The value of ka for Ha is?

1 answer:

3 0

If 0. 22 m aqueous solution of the weak acid hA at 25. 0 °C has a ph of 4. 15, the value of ka for HA is 2.27 × 10^(-8).

<h3>What is an aqueous solution?</h3>

The aqueous solution is simply defined as something which has been dissolved in water. The aqueous symbol is denoted as (aq).

Given,

pH = 4.15

Concentration of HA = 0.22 M

Firstly, we will calculate the concentration of H+ ion

pH=-log [H+]

4.15 =-log [H+]

= 7.08x 10^{-5}

Secondly we will calculate the value of Ka

for HA is

The equilibrium reaction will be:

HA----- (H+) + (A-)

Given,

Concentration of H+

= Concentration of A-

= 7.08 x 10^{-5} M

The expression of Ka for HA will be,

Ka = [A-] [H+]/[ HA]

= 2.27 × 10^(-8)

Thus we concluded that the value of ka for HA for weak acid HA is 2.27 × 10^(-8).

learn more about aqueous solution or Ka:

brainly.com/question/12481995

#SPJ4

You might be interested in

Why does the study of science have limitations

oksano4ka [1.4K]

Science doesn't make moral judgments, doesn't make aesthetic judgments, doesn't tell you how to use scientific knowledge, doesn't draw conclusions about supernatural explanations. So that's why I think it has limitations.

7 0

3 years ago

What are the disadvantages of aluminium fir building cars

Wittaler [7]

Disadvantages of aluminum in building cars include:

On average, aluminum is more expensive than steel, as much as two to three times.

Aluminum is not easily welded. If a steel door or panel suffers a crack, often it cam be welded back together easily, primed and repainted so its difficult to tell any body work has been performed. This cannot be done with aluminum. Steel also can be bent and shaped as needed.

Body shops and even dealer service centers are currently equipped for steel work with technicians skilled in the art of welding and steel fabrication. The cost of switching over to an infra structure designed specifically for all-aluminum vehicles or mass production of aluminum vehicles and components would be high.

4 0

3 years ago

If 8.50 g of phosphorus reacts with hydrogen gas at 2.00 atm in a 10.0-L container at 298 K, calculate the moles of PH3 produced

ahrayia [7]

Answer:

The moles of PH₃ produced are 0.2742 and the total number of moles of gas present at the end of the reaction is 0.6809.

Explanation:

Phosphorus reacts with H₂ according to the balanced equation:

P₄ (s) + 6 H₂ (g) ⇒ 4 PH₃ (g)

By stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of each compound participate in the reaction:

P₄: 1 mole
H₂: 6 moles
PH₃:4 moles

Being the molar mass of the compounds:

P₄: 124 g/mole
H₂: 2 g/mole
PH₃: 34 g/mole

The following mass amounts of each compound participate in the reaction:

P₄: 1 mole* 124 g/mole= 124 g
H₂: 6 mole* 2 g/mole= 12 g
PH₃: 4 moles* 34 g/mole= 136 g

An ideal gas is characterized by three state variables: absolute pressure (P), volume (V), and absolute temperature (T). The relationship between them constitutes the ideal gas law, an equation that relates the three variables if the amount of substance, number of moles n, remains constant and where R is the molar constant of the gases:

P * V = n * R * T

In this case you know:

P= 2 atm
V= 10 L
n= ?
R= 0.082 $\frac{atm*L}{mol*K}$
T= 298 K

Replacing:

2 atm*10 L= n*0.082 $\frac{atm*L}{mol*K}$ *298 K

and solving you get:

$n=\frac{2 atm*10 L}{0.082\frac{atm*L}{mol*K}*298 K }$

n=0.818 moles

The limiting reagent is one that is consumed first in its entirety, determining the amount of product in the reaction. When the limiting reagent is finished, the chemical reaction will stop.

To determine the limiting reagent, you can use a simple rule of three as follows: if 6 moles of H₂ react with 124 g of P₄, 0.818 moles of H₂ with how much mass of P₄ will it react?

$mass of P_{4}=\frac{0.818 moles of H_{2}*124 grams of P_{4}}{6 moles of H_{2}}$

mass of P₄= 16.90 grams

But 16.90 grams of P₄ are not available, 8.50 grams are available. Since you have less mass than you need to react with 0.818 moles of H₂, phosphorus P₄ will be the limiting reagent.

Then you can apply the following rules of three:

If 124 grams of P₄ produce 4 moles of PH₃, 8.50 grams of P₄, how many moles do they produce?

$moles of PH_{3} =\frac{8.5 grams of P_{4}*4 moles of PH_{3} }{124grams of P_{4}}$

moles of PH₃=0.2742

If 124 grams of P₄ react with 6 moles of H₂, 8.50 grams of P₄ with how many moles of H₂ do they react?

$moles of H_{2} =\frac{8.5 grams of P_{4}*6 moles of H_{2} }{124grams of P_{4}}$

moles of H₂= 0.4113

If you have 0.818 moles of H₂, the number of moles of gas H₂ present at the end of the reaction is calculated as:

0.818 - 0.4113= 0.4067

Then the total number of moles of gas present at the end of the reaction will be the sum of the moles of PH₃ gas and H₂ gas that did not react:

0.2742 + 0.4067= 0.6809

Finally, <u><em>the moles of PH₃ produced are 0.2742 and the total number of moles of gas present at the end of the reaction is 0.6809.</em></u>

5 0

2 years ago

PLZ HELP!<br><br> How do you think changing the angle of a ramp will affect work done?

kogti [31]

Answer: The steepness of a ramp affects it by making it easier or harder.

Explanation: It's a bit situational. If you were going up a steep ramp with a heavy load, it will increase the work necessary, whereas if you were going down a ramp, it would decrease the work necessary. If you need this simply put, think about biking up and down a hill. It would be easier going down than up.

6 0

2 years ago

Explain the role of a primary consumer and a secondary consumer in a food web.

Usimov [2.4K]

Answer:

Explanation:

Secondary consumers are organisms that eat primary consumers for energy. Primary consumers are always herbivores, or organisms that only eat autotrophic plants.

Carnivores only eat other animals, and omnivores eat both plant and animal matter.

7 0

2 years ago