answer.
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
sammy [17]
2 years ago
9

In a 0.100 m hf solution, the percent dissociation is determined to be 9.5%. calculate the ka for hf based on this data.

Chemistry
1 answer:
Elden [556K]2 years ago
3 0

Answer : The dissociation constant (Ka) = 9.025 × 10^{-4}

Solution :  Given,

                Concentration HF solution = 0.100 M

                 % Dissociation = 9.5 %

The equation for dissociation of HF is :

                  HF \rightleftharpoons H^{+}+ F^{-}

The Ka expression for HF is :

Ka=\frac{[H^{+}][F^{-}]}{[HF]}        ............. (1)

Step 1 : we find the [H^{+}] by using the concentration and % dissociation.

 [H^{+}] = Concentration HF solution ×  % Dissociation

 [H^{+}] = 0.100 M × \frac{9.5}{100} = 9.5 × 10^{-3} M

Step 2 : For [F^{-}] , the concentration of  [F^{-}] is equal to the  [H^{+}]. From the above equation the stoichiometry of   [F^{-}] and [H^{+}] is 1:1.

Therefore,

[F^{-}] =  [H^{+}]  = 0.100 M × \frac{9.5}{100} =    =  9.5 × 10^{-3} M

         

Now, put all the values in equation (1), we get

Ka=\frac{(9.5\times10^{-3})\times(9.5\times10^{-3})}{(0.1)}

           = 9.025 × 10^{-4}

You might be interested in
The amount of gas that occupies 36.52 L at 68.0°C and 672 mm Hg is __________ mol.
ASHA 777 [7]
We assume that this gas is an ideal gas. We use the ideal gas equation to calculate the amount of the gas in moles. It is expressed as:

PV = nRT
(672) (1/760) (36.52) = n (0.08206) ( 68 +273.15)
n = 1.15 mol of gas

Hope this answers the question. Have a nice day.
7 0
2 years ago
**PLATO QUESTION, PLEASE ANSWER CORRECTLY, THANK YOU**
Nata [24]
The answers are the following that can be answered using the chart:

A. Which type of hurricane is expected to strike more frequently this century?
Category 4 + 5C. In general, will hurricanes likely become stronger or weaker this century?
Stronger, because there are more stronger ones thant he weaker ones that can result to hurricane.

E. Which types of hurricanes are expected to drop in frequency by more than 25% this century?
Categories 1, 2, 3


4 0
2 years ago
An unknown compound melting at 131 - 133 C. It is thought to be one of the following compounds: trans-cinnamic acid (133-134); b
Vesnalui [34]

Answer:

benzamide

Explanation:

Compound            melting Point ,ºC          Melting Pont Mixture, ºC

       X                          131 - 133

trans-cinnamic            133 - 134                      110 - 120

acid

benzamide                 128 - 130                       130-132

malic acid                   131   -133                        114 -124

Benzoin                      135 - 137                        108 - 116

The compound X is benzamide since the melting point range is the one closest to this compound (  130-132 ºC)

The reason there is not an exact match is not due due to the presence of impurities. The presence of impurities always lower the melting point ( it is a coligative property such as the melting point depresion of salt and water )

The reason for the deviation must be  be some other factors such as preparation of the sample in the capillary, errors in reading the thermometer, rate of heating, etc.

5 0
2 years ago
"The compound K2O2 also exists. A chemist can determine the mass of K in a sample of known mass that consists of either pure K2O
o-na [289]

Answer:

Yes, the chemist can determine which compound is in the sample.

Explanation:

In 1 mole of K₂O, the mass of K is 2 × 39.1 g = 78.2 g and the mass of K₂O is 94.2 g. The mass ratio of K to K₂O is 78.2 g / 94.2 g = 0.830.

In 1 mole of K₂O₂, the mass of K is 2 × 39.1 g = 78.2 g and the mass of K₂O₂ is 110.2 g. The mass ratio of K to K₂O₂ is 78.2 g / 110.2 g = 0.710.

If the chemist knows the mass of K and the mass of the sample, he or she must calculate the mass ratio of K to the sample.

  • If the ratio is 0.830, the compound is pure K₂O.
  • If the ratio is 0.710, the compound is pure K₂O₂.
  • If the ratio is not 0.830 or 0.710, the sample is a mixture.
6 0
2 years ago
Acrylonitrile () is the starting material for many synthetic carpets and fabrics. It is produced by the following reaction. If 1
pychu [463]

2C3H6 (g) + 2NH3 (g) + 3O2 (G) -> 2C3H3N (g) + 6H2O (g)

First off.. not a chem board.. but n e way.

This is a limiting reagent problem.

set it up as a DA problem.(Dimension Analysis)

Start with what you want.

you want Grams of acrylonitrile (C3H3N)

so start with that (Using ACL in place of Acrylonitrile.. just for ease of typing)

(g) = (53 g of ACL/1mol ACL) (2 mols ACL/2 mol C3H6)/ (1mol C3H6/42 grams) (15.0 grams)

solve that you wiill get grams of Acrylonitrile created by 15 grams oc C3H6 = 18.9g

Same setup for the two other reactants.

so i did it and for

oxygen I got 11.04 grams

and for Ammonia i got 15.29 grams

So the most you can make is 11.04 grams because if you have ot make any more .. you will have to get more O2 .. but since you have only 10 grams of it .. that is the most u can make in this reaction.

Both the other reactants are in excess.

rate brainliest pls

3 0
2 years ago
Other questions:
  • Old photographic flashbulbs burn magnesium metal in a reaction that causes a flash of brilliant white light. A photographer woul
    7·2 answers
  • What is net ionic equation borax hydrolysis?
    10·1 answer
  • The circles, or orbits, for electrons are called energy levels. Each level can hold only a certain number of electrons. Add elec
    11·2 answers
  • Identify the examples of diffusion in the list below. Check all that apply.
    15·2 answers
  • When a solute molecule is solvated, is energy released or absorbed?
    9·1 answer
  • How did the scientific method impact work of scientists beginning in the 16th century
    7·2 answers
  • What pressure would a gas mixture in a 10.0 l tank exert if it were composed of 48.5 g he and 94.6 g co2 at 398 k?
    5·2 answers
  • Platinum, which is widely used as a catalyst, has a work function φ(the minimum energy needed to eject an electron from the meta
    8·1 answer
  • Which image exclusively represents the principle of radiation? A) IV B) III C) II D) I
    8·2 answers
  • Copper atoms are heavier than magnesium atoms. So, although each atom of magnesium can produce one atom of copper, the masses wo
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!