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
Misha Larkins [42]
3 years ago
13

The ph of 0.255 m hcn is 4.95. What is the value of ka for hydrocyanic acid?

Chemistry
1 answer:
Lera25 [3.4K]3 years ago
5 0

Answer:

Ka = 4.9 X 10^-9

Explanation:

when the pH  is 4.95

the [H+] = 10^-4.95

[H+] = 1.122 e-5

since the equilibrium equation is:

HCN <=> 1 mole H+  &  1 mole CN-

then

[H+] = [CN-]

when

HCN <=>  H+  &   CN-

Ka = [ H+]  [CN-]  / [HCN]

Ka = [ 1.122 e-5]  [ 1.122 e-5]  / [0.255]

Ka = 1.256 e-10 / 0.255

Ka = 4.94 e-9

which rounds off to 2 sig figs into

Ka = 4.9 X 10^-9

======================

p.s. it was the pH pf 4.95 that limited the calculations to 2 sig figs

You might be interested in
Which of these takes place when a chemical change occurs? option 1: Bonds connecting atoms in products and reactants form. optio
Tamiku [17]

Answer: Out of the given options bonds connecting atoms in reactants break, and bonds connecting atoms in products form are the changes which takes place when a chemical change occurs.

Explanation:

A change that leads to the change in chemical composition of a substance is called a chemical change.

For example, 2NH_{3} \rightarrow N_{2} + 3H_{2}

Here, bond between the reactant atoms nitrogen and hydrogen is broken down.

On the other hand, bond connecting the products that is N_{2} and H_{2} is formed.

Thus,, we can conclude that out of the given options bonds connecting atoms in reactants break, and bonds connecting atoms in products form are the changes which takes place when a chemical change occurs.

4 0
2 years ago
A solution has a pOH of 8.20. What is the concentration of H3O+?
Sedbober [7]

Answer:

.000001585

Explanation:

14-8.20=5.8

10^-5.8 = H3O+

- Hope this helped! Please let me know if you need further explanation.

7 0
3 years ago
What are the conditions to liquefy a gas ?
kykrilka [37]
Decreasing temperature and increasing pressure
5 0
3 years ago
¿que se necesita para escribir un informe de experimento? Plis ​
Ludmilka [50]

Answer:

Explanation:

Introducción. Dentro de la introducción, el investigador limita el estudio. Muestra los datos generales importantes y...

Hipótesis. La hipótesis consiste en una apreciación que el investigador hace en torno al problema. Se define como una...

Objetivos. Los objetivos de un estudio son los movimientos que se deben hacer para solucionar el

4 0
2 years ago
Read 2 more answers
Calculate the number of moles of C2H6 (nC2H6) in 1.80×1023 molecules of C2H6.
dem82 [27]
1481.40 molecules of C2H6
6 0
3 years ago
Other questions:
  • Which of these chemicals is definitely INorganic?
    12·2 answers
  • Why do scientists measure and record mass instead of weight
    13·2 answers
  • Zelda noticed a puddle outside her front door. She saw that the puddle got smaller every day, mil the
    15·1 answer
  • How many grams are there in 3.3 x 1023 particles of N2I6?
    13·1 answer
  • The temperature of 150 mL of water is 25°C. What must happen for the temperature of the water to increase to 35°C?
    15·1 answer
  • Select the keyword or phrase that will best complete each sentence about the three general rules of for drawing Lewis structures
    7·1 answer
  • Chemistry Stoichiometry Question
    5·1 answer
  • Plz I need help is the 2nd time I post this
    13·1 answer
  • the roof of a building is 0.2km^2. during a rainstorm, 5.5 cm of rain was measured to be sitting on the roof. what is the mass i
    13·1 answer
  • What might be a scientific question
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!