1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Zanzabum
2 years ago
13

Why is it important to have long term measurements when studying ecosystems

Chemistry
1 answer:
Alex Ar [27]2 years ago
5 0
Because ecosystems don't change over one day, they change over a long period of time. Plus, something that happens may be because of more than just one change.
You might be interested in
Balance NaOH + H3PO4->H2O + Na3PO4
Masteriza [31]

Answer:

3NaOH + H3PO4 ---> 3H2O + Na3PO4

Explanation:

7 0
2 years ago
Calculate the pH of each of the following solutions: (a) 0.1000M Propanoic acid (HC3H5O2, Ka= 1.3x10-5 ) (b) 0.1000M sodium prop
jek_recluse [69]

(a) The pH of 0.1000 M propanoic acid (HC3H5O2) is 2.9.

(b) The pH of 0.1000 M sodium propanoate (NaC3H5O2) is 8.9.

(c) The pH of 0.1000 M propanoic acid (HC3H5O2) and 0.1000 M sodium propanoate (NaC3H5O2) is 4.9.

<h3>Further explanation:</h3>

(a)

Given information:

The value of acid ionization constant for propanoic acid is  1.3 x 10^{-5} .

The initial concentration of propanoic acid is  .

To calculate:

The pH of 0.1000 M propanoic acid solution.

Solution:

Propanoic acid  is a weak acid. It ionizes partially in water as follows:

 

The expression for acid dissociation constant is,

                                                            …… (1)

Here,

 is ionization constant of propanoic acid.

is the equilibrium concentration of propanoate ion.

is the equilibrium concentration of hydronium ion.

 is the equilibrium concentration of propanoic acid.

ICE table (1):

 

Refer ICE table (1),

 

Substitute the values form the ICE table (1) in equation (1).

 

The approximation x is very small is valid. Therefore, the value of x can be neglected. Above equation can be modified as,

 

Rearrange above equation for x.

                                                                                                           …… (2)

Substitute   for   in equation (2) to calculate the value of x.

 

Therefore, from the ICE table (1) the concentration of hydronium ion is,

 .

The negative logarithm of hydronium ion concentration is defined as the pH of the solution. Mathematically,

                                                                                                               …… (3)

Substitute    for    in equation (3) to calculate the pH of the solution.

 

(b)

Given information:

The value of acid ionization constant for propanoic acid is  .

The initial concentration of sodium propanoate is  .

To calculate:

The pH of 0.1000 M sodium propanoate solution.

Solution:

Sodium propanoate  is conjugate base of weak propanoic acid. It undergoes hydrolysis in water to yield hydroxide ion in the solution as follows:

                                                        …… (4)

Propanoic acid  is a weak acid. It ionizes partially in water as follows:

                                                       …… (5)

Dissociation reaction for water is written as follows:

                                                                                       …… (6)

From equation (4), (5), and (6) the relationship between   and   is,

                                                                                                                              …… (7)

Substitute   for   and   for   in equation (7).

 

ICE table (2):

 

The expression for base dissociation constant is,

                                                                                                     …… (8)

Here,

is base ionization constant.

is the equilibrium concentration of propanoate ion.

is the equilibrium concentration of hydroxide ion.

 is the equilibrium concentration of propanoic acid.

From the ICE table (2),

 

Substitute the values form the ICE table (2) in equation (8).

 

The approximation y is very small is valid. Therefore, the value of y can be neglected. Above equation can be modified as,

 

Rearrange above equation for y.

                                                                                                           …… (9)

Substitute   for   in equation (9) to calculate the value of y.

 

Therefore, from the ICE table (2) the concentration of hydroxide ion is,

 

The negative logarithm of hydroxide ion concentration is defined as pOH of the solution. Mathematically,

                                                                                                           …… (10)

Substitute    for    in equation (10) to calculate pOH of the solution.

 

The relation between pH and pOH is as follows:

                                                                                                                   …… (11)

Substitute 5.057 for pOH in equation (11) to calculate the pH of the solution.

 

(c)

Given information:

The value of acid ionization constant for propanoic acid is  .

The initial concentration of sodium propanoate is  .

The initial concentration of sodium propanoate is  .

To calculate:

The pH of 0.1000 M sodium propanoate and 0.1000 M propanoic acid solution.

Solution:

Propanoic acid is a weak acid, and sodium propanoate is salt of the conjugate base of propanoic acid. Thus, propanoic acid and sodium propanoate will form a buffer system.

The pH of the buffer solution can be determined with the help of the Henderson-Hasselbalch equation. Mathematically,

 

For propanoic acid and sodium propanoate buffer system, the Henderson-Hasselbalch equation can be modified as,

                                                                                               …… (12)

The negative logarithm of acid ionization constant is equal to  .

                                                                                                                …… (13)

Substitute   for  in equation (13).

 

Substitute    for  ,   for   and 4.9 for    in equation (12).

 

Learn more:

1. About Henderson-Hasselbalch equation brainly.com/question/12999557

2. Learn more about how to calculate moles of the base in given volume brainly.com/question/4283309

Answer details:

Grade: Senior School

Subject: Chemistry

Chapter: Ionic equilibria

Keywords: ionic equilibrium, propanoic acid, sodium propanoate, ionization constant, weak acid, conjugate base, equilibrium concentration, hydronium ion, hydroxide ion, pH, pOH, ICE table, negative logarithm, buffer solution, Henderson-Hasselbalch equation, 0.1000 M, 4.9, 8.9, 2.9.

3 0
3 years ago
Read 2 more answers
Which of these best matches a planet in the solar system with its characteristic?
Lera25 [3.4K]

Uranus. Its axis is tilted to almost 90 degrees.

6 0
3 years ago
Read 2 more answers
A sample of chlorine gas occupies a volume of 707 ml at 2.90 atm. What is the new pressure in torr if the volume is compressed t
dolphi86 [110]

Answer:

The new pressure is 3850 torr.  

Explanation:

The relation between volume and pressure is inverse as per Boyle's law. Its mathematical form is given by :

P_1V_1=P_2V_2

Here,

P_1=2.9\ atm

V_1=707\ mL

V_2=0.533\ L

Let P_2 is the new pressure. So using Boyle's law we get :

P_2=\dfrac{P_1V_1}{V_2}\\\\P_2=\dfrac{2.9\times 707}{0.533}\\\\P_2=3846.71\ \text{torr}

or

P_2=3850\ \text{torr}

So, the new pressure is 3850 torr.  

3 0
3 years ago
the reaction of Al with HCl to produce hydrogen gas. What is the pressure of H2 if the hydrogen gas collected occupies 14 L at 3
juin [17]

Answer:

Pressure for H₂ = 11.9 atm

Option 5.

Explanation:

We determine the complete reaction:

2Al(s) +  6HCl(aq) → 2AlCl₃(aq) + 3H₂(g)

As we do not know anything about the HCl, we assume that the limiting reactant is the Al and the acid is the excess reagent.

Ratio is 2:3.

2 moles of Al, can produce 3 moles of hydrogen

Therefore 4.5 moles of Al must produce (4.5 . 3) / 2 = 6.75 moles

Now we can apply the Ideal Gases law to find the H₂'s pressure

P . V  = n . R . T → P = (n . R .T) / V

We replace data: (6.75 mol . 0.082L.atm/mol.K . 300K) / 14L

Pressure for H₂ = 11.9 atm

6 0
3 years ago
Read 2 more answers
Other questions:
  • Which practice is an unsustainable way of managing resources?
    15·1 answer
  • Which of the following statements best describes the Aufbau principle?
    8·1 answer
  • In salt, what is the nature of the bond between sodium and chlorine? in salt, what is the nature of the bond between sodium and
    12·1 answer
  • The state of matter with a specific volume but no definite shape is the _____ state.
    9·1 answer
  • Why is objectivity important for scientific investigations?
    6·1 answer
  • Bond length is the distance between the centers of two bonded atoms. on the potential energy curve, the bond length is the inter
    15·2 answers
  • You want to determine the protein content in milk with the Kjeldahl method. You take 100 g whole milk and use 100 mL of 0.5 M hy
    14·1 answer
  • Use your understanding of the ideal gas law to
    7·2 answers
  • Consider the reaction: P4 + 6Cl2 = 4PCl3.
    9·1 answer
  • PLEASE HELP!!!! <br><br> Draw a representation of John Dalton’s atomic model.
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!