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
Elza [17]
2 years ago
5

What is the pH if 1mL of 0.1M HCl is added to 99mL of pure water?

Chemistry
1 answer:
coldgirl [10]2 years ago
5 0

Answer:

pH of buffer after addition of 1 mL of 0,1 M HCl = 7,0

Explanation:

It is possible to use Henderson–Hasselbalch equation to estimate pH in a buffer solution:

pH = pka + log₁₀

Where A⁻ is conjugate base and HA is conjugate acid

The equilibrium of phosphate buffer is:

H₂PO₄⁻ ⇄ HPO4²⁻ + H⁺    Kₐ₂ = 6,20x10⁻⁸; pka=7,2

Thus, Henderson–Hasselbalch equation for 7,00 phosphate buffer is:

7,0 = 7,2 + log₁₀ \frac{[HPO4^{2-}] }{[H2PO4^{-}]}

Ratio obtained is:

0,63 = \frac{[HPO4^{2-}] }{[H2PO4^{-}]}

As the problem said you can assume [H₂PO₄⁻] = 0,1 M and [HPO4²⁻] = 0,063M

As the amount added of HCl is 0,001 M the concentrations in equilibrium are:

H₂PO₄⁻   ⇄   HPO4²⁻ +        H⁺

0,1 M +x      0,063M -x  0,001M -x -<em>because the addition of H⁺ displaces the equilibrium to the left-</em>

Knowing the equation of equilibrium is:

K_{a} = \frac{[HPO_{4}^{2-}][H^{+}]}{[H_{2} PO_{4}^{-}]}

Replacing:

6,20x10⁻⁸ = \frac{[0,063-x][0,001-x]}{[0,1+x]}

You will obtain:

x² -0,064 x + 6,29938x10⁻⁵ = 0

Thus:

x = 0,063 → No physical sense

x = 0,00099990

Thus, [H⁺] in equilibrium is:

0,001 M - 0,00099990 = 1x10⁻⁷

Thus, pH of buffer after addition of 1 mL of 0,1 M HCl =

-log₁₀ [1x10⁻⁷] = 7,0

A buffer is a solution that can resist pH change upon the addition of an acidic or basic components. In this example you can see its effect!

I hope it helps!

You might be interested in
Abdid is an astronomer who has been observing objects that orbit the Sun in the asteroid belt. He finds a previously undiscovere
Elza [17]
Since it is round and it is the asteroid belt it is most likely that he found a dwarf planet 
6 0
3 years ago
Read 2 more answers
Convert 6.33×10−6 cg to nanograms.
tensa zangetsu [6.8K]
5.73e+8 hope this help
5 0
3 years ago
Addition of 50. J to a 10.0-g sample of a metal will cause the temperature of a metal to rise from 25ºC to 35ºC. The specific he
Snowcat [4.5K]

Answer:

b) C = 0.50 J/(g°C)

Explanation:

  • Q = mCΔT

∴ Q = 50 J

∴ m = 10.0 g

∴ ΔT = 35 - 25 = 10 °C

specific heat (C) :

⇒ C = Q / mΔT

⇒ C = 50 J / (10.0 g)(10 °C)

⇒ C = 0.50 J/(g°C)

7 0
2 years ago
The ___ blends into outer space.
Paraphin [41]

Answer:

Exosphere

Explanation:

it is found at the end reaching outer space

3 0
2 years ago
PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP
vivado [14]

Answer:

not sure about it .I also need an answer

8 0
2 years ago
Other questions:
  • If the electronegativity difference between the elements in the ionic compound nax has the ratio of 2 to 1 what element is x
    13·1 answer
  • Which family on the periodic table has a filled outer energy level?
    8·1 answer
  • Where is the sun shining most directly when we are having winter in the Northern Hemisphere?
    14·1 answer
  • How have chemists changed our daily lives the most
    9·1 answer
  • What is an orbital?
    11·2 answers
  • Describe a dinner you would like to eat that includes all the main nutrients, but is low in the nutrients that you should limit.
    10·1 answer
  • Looking at page 14 of the earth science tables, how does the temperature change as a balloon rises through the Troposphere Strat
    13·1 answer
  • Someone please help me answer this.
    15·1 answer
  • A
    10·1 answer
  • Which of the following are products when magnesium metal is placed in hydrochloric acid? (Correct answer should be D but why)
    15·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!