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2 years ago

9

Lactic acid, which is found in milk products, has a pKa of 3.85. A 50.0 mL solution of 0.05 M lactic acid is titrated with 0.025

M sodium hydroxide. What is the pH of the solution after 64.0 mL of the sodium hydroxide has been added

1 answer:

WINSTONCH [101]2 years ago

8 0

I think the ph range would be 3

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Is the osmotic pressure of a 0.10 M solution of NaCl greater than, less than, or equal to that of a 0.10 M solution of KBr?a. eq

jonny [76]

Answer:

a. equal to

Explanation:

The <em>osmotic pressure</em> is calculated by the formula:

π = <em>i</em> * M * R * T

Where π is the osmotic pressure, M is the concentration, R is a constant, T is temperature and <em>i</em> is the van't Hoff's factor (the number of ions a compound forms when dissolved in water,<u> for both NaCl and KBr is 2</u>).

Because R is always the same, and <u>Temperature and Concentration are equal between the two solutions</u>, the osmotic pressure of both solutions are also equal.

4 0

3 years ago

Which lists only metalloids?

enot [183]

Answer:

boron (B), germanium (Ge), and tellurium (Te)

6 0

2 years ago

Read 2 more answers

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:

1)

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

2)

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

3)

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 <u>C. 1.18 times 10^15 s^-1.</u>

4)

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 <u>B. 4.39 times 10^-19 J</u>.

5)

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 <u>B. Energy is absorbed</u>.

6)

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

7)

The electronic configuration of barium atom is:

<u>1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^6 5s^2 4d^10 5p^6 6s^2 </u>

8 0

3 years ago

How can i find the number of electrons are gained or lost

wel

15. 1 were lost

16. 3 were gained

17. 2 were lost

18. 1 was gained

You can figure that out by looking at the number nest to the molecule with a plus or minus sign next to it

+ = gained

- = lost

6 0

3 years ago

Given the value of the equilibrium constant (Kc) for the equation (a), calculate the equilibrium constant for equation (b)

matrenka [14]

Answer: The value of equilibrium constant for new reaction is $1.92\times 10^{-25}$

Explanation:

The given chemical equation follows:

$O_2(g)\rightarrow \frac{2}{3}O_3(g)+\frac{1}{2}O_2(g)$

The equilibrium constant for the above equation is $5.77\times 10^{-9}$

We need to calculate the equilibrium constant for the equation of 3 times of the above chemical equation, which is:

$3O_2(g)\rightarrow 2O_3(g)$

The equilibrium constant for this reaction will be the cube of the initial reaction.

If the equation is multiplied by a factor of '3', the equilibrium constant of the new reaction will be the cube of the equilibrium constant of initial reaction.

The value of equilibrium constant for reverse reaction is:

$K_{eq}'=(5.77\times 10^{-9})^3=1.92\times 10^{-25}$

Hence, the value of equilibrium constant for new reaction is $1.92\times 10^{-25}$

5 0

2 years ago