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
Svetach [21]
3 years ago
5

If the ka of a monoprotic weak acid is 8.4 × 10-6, what is the ph of a 0.45 m solution of this acid

Chemistry
1 answer:
olga_2 [115]3 years ago
7 0

Consider the acid to be HA so the equation for acid will be:

HA+H₂O---->H₃O⁺ +A⁻

Initial: 0.45 0 0 0

Final 0.45-x x x x

Kₐ= [H₃O⁺][A⁻]/[HA]

= x²/0.45-x

8.4 × 10⁻⁶= x²/0.45-x

3.78× 10⁻⁶-8.4 × 10⁻⁶x=x²

On solving equation,

x= 0.0018

[H₃O⁺]=[A⁻]=x=0.0018

pH= -log[H₃O⁺]

= -log[0.0018]

= 2.74

You might be interested in
A piece of copper alloy with a mass of 85.0 g is heated from 30. °C to 45 °C. In the process, it absorbs 523 J of energy as heat
Ne4ueva [31]

Answer:

410.196 J/[kg*°C].

Explanation:

1) the equation of the energy is: E=c*m*(t₂-t₁), where E - energy (523 J), c - unknown specific heat of copper, m - mass of this copper [kg], t₂ - the final temperature, t₁ - initial temerature;

2) the specific heat of copper is:

c=\frac{E}{m*(t_2-t_1)}; \ => \ c=\frac{523}{0.085*(45-30)}=\frac{523}{1.275}=410.196[\frac{J}{kg*C}].

6 0
2 years ago
Which of the following is not an example of a molecule A. Mn     B. KOH    C. O₃    D. H₂S
goldenfox [79]

look at the chemical tables.  but i believe it is A

3 0
2 years ago
Read 2 more answers
Where would you look for igneous rocks? Why?
Brut [27]

Answer:

Where Igneous Rocks Are Found. The deep seafloor (aka... the oceanic mantle) is made almost entirely of basaltic rocks, with peridotite underneath in the mantle.

Explanation: im pretty sure thats right at least

6 0
3 years ago
Breathe in air container more ____ than breathed out air
TEA [102]

Answer:

c

Explanation:

carbon dioxide ......

5 0
2 years ago
An ideal gas contained in a piston-cylinder assembly is compressed isothermally in an internally reversible process.
Tju [1.3M]

Answer:

a) \Delta S

b) entropy of the sistem equal to a), entropy of the universe grater than a).

Explanation:

a) The change of entropy for a reversible process:

\delta S=\frac{\delta Q}{T}

\Delta S=\frac{Q}{T}

The energy balance:

\delta U=[tex]\delta Q- \delta W

If the process is isothermical the U doesn't change:

0=[tex]\delta Q- \delta W

\delta Q= \delta W

Q= W

The work:

W=\int_{V1}^{V2}P*dV

If it is an ideal gas:

P=\frac{n*R*T}{V}

W=\int_{V1}^{V2}\frac{n*R*T}{V}*dV

Solving:

W=n*R*T*ln(V2/V1)

Replacing:

\Delta S=\frac{n*R*T*ln(V2/V1)}{T}

\Delta S=n*R*ln(V2/V1)}

Given that it's a compression: V2<V1 and ln(V2/V1)<0. So:

\Delta S

b) The entropy change of the sistem will be equal to the calculated in a), but the change of entropy of the universe will be 0 in a) (reversible process) and in b) has to be positive given that it is an irreversible process.

7 0
3 years ago
Other questions:
  • Which of the following equations represents an unbalanced neutralization reaction equation? a) HBr + Ca(OH)2 → CaBr2 + H2O b) SO
    14·2 answers
  • Cation and anion of CuCl2
    6·1 answer
  • Which statement describes the electron sea model for metallic bonding?
    8·2 answers
  • What is a successful outcome for using a scientific method?
    15·1 answer
  • What is the frequency of light with a wave- length of 4.0 ×10−7 m?
    12·1 answer
  • Need help real quick with these questions
    10·1 answer
  • What is a group in the periodic table of elements?
    5·2 answers
  • A sample of an ideal gas is cooled from 50.0°C to 25.0°C in a sealed container at constant volume.
    6·1 answer
  • Describe the behavior of electrons in single, double, and triple bonds. Compare and contrast their properties, listing an exampl
    15·1 answer
  • CaCl2 (s) + 2 H2O → Ca(OH)2 (aq) + 2 HCl (g) When Addie added CaCl2 to the water in her flask, she noted that the flask heated u
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!