All categories

3 years ago

A 1.0 M H2S solution has a pH = 3.75 at equilibrium. What is the value of Ka?

Chemistry

2 answers:

MrRa [10]3 years ago

7 0

The answer is 3.16*10-8

Lelechka [254]3 years ago

6 0

The answer is A, for help I watched some khan academy vids, they're very helpful

You might be interested in

What’s Silicon’s melting point?

torisob [31]

Answer:

2,577°F

Also,

Boron: 3,769°F (2,076°C)

Neon: -415.5°F (-248.6°C)

Beryllium: 2,349°F (1,287°C)

8 0

3 years ago

Read 2 more answers

g If 50.0 mL of a 0.75 M acetic acid solution is titrated with 1.0 M sodium hydroxide, what is the pH after 10.0 mL of NaOH have

V125BC [204]

Answer:

pH = 2.66

Explanation:

Acetic Acid + NaOH → Sodium Acetate + H₂O

First we calculate the number of moles of each reactant, using the given volumes and concentrations:

0.75 M Acetic acid * 50.0 mL = 37.5 mmol acetic acid

1.0 M NaOH * 10.0 mL = 10 mmol NaOH

We calculate how many acetic acid moles remain after the reaction:

37.5 mmol - 10 mmol = 27.5 mmol acetic acid

We now calculate the molar concentration of acetic acid after the reaction:

27.5 mmol / (50.0 mL + 10.0 mL) = 0.458 M

Then we calculate [H⁺], using the following formula for weak acid solutions:

[H⁺] = $\sqrt{C*Ka}=\sqrt{0.458M*1.76x10^{-5}}$

[H⁺] = 0.0028

Finally we calculate the pH:

pH = -log[H⁺]

pH = 2.66

8 0

2 years ago

I don’t really understand, if anybody can help I’ll really appreciate it ! Thank you.

Alex_Xolod [135]

Answer:

175

Explanation:

3 0

3 years ago

Which of the following frequencies corresponds to light with the longest wavelength? A) 3.00 times 10^13 s^-1 B) 4.12 times 10^5

Vsevolod [243]

Answer:

1) B. 4.12 times 10^5 s^-1

2) B. frequency-v

3) C. 1.18 times 10^15 s^-1

4) B. 4.39 times 10^-19 J

5) B. Energy is absorbed

6) C. 3

7) 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^6 5s^2 4d^10 5p^6 6s^2

Explanation:

The wavelength is inversely proportional to the frequency. Thus, the smallest frequency shall correspond to the longest wavelength. Thus, the correct answer is B. 4.12 times 10^5 s^-1

B. frequency-v are wrongly paired because frequency is represented by f. Thus, correct pair will be frequency-f.

The relationship between wavelength (λ) and frequency (f) is:

c = fλ

f = c/λ

where, c = speed of light = 3 x 10^8 m/s

f = (3x10^8 m/s) / (254 x 10^-9 m)

f = 1.18 x 10^15 s^-1

Thus, the correct option is C. 1.18 times 10^15 s^-1.

The energy of photon is given as:

E = hc/λ

where, c = speed of light = 3 x 10^8 m/s

h = Plank's Constant = 6.625 x 10^-34 J.s

E = (6.625 x 10^-34 J.s)(3 x 10^8 m/s) / (453 x 10^-9 m)

E = 4.39 x 10^-19 J

Thus, the correct option is B. 4.39 times 10^-19 J.

Since, the higher energy levels away from nucleus have higher energies. So, in order to move an electron from lower to higher or distant energy level, it must absorb energy from external source. So, the correct option is B. Energy is absorbed.

The P-Sub-level has three orbitals, each having two electrons. Thus, P-Sub-Level accommodates total of 6 electrons. The correct option is C. 3

The electronic configuration of barium atom is:

1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^6 5s^2 4d^10 5p^6 6s^2

8 0

3 years ago

PLEASE HELPPPP! HOW DO I DO THIS???

kow [346]

Answer:

1552.83J Released

Explanation:

1. mass/m=225

Initial temp:86C, final:32.5C

Changed Temp: 32.5-86= -53.5C

s=0.129 J/gC

Formula: q= m times s times changed Temp.

q=(225)(0.129)(-53.5)

q= -1552.83 J

q=1552.83 J Released

8 0

3 years ago