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
aliya0001 [1]
3 years ago
15

Which of the following statements is NOT true of the Lewis Dot Diagrams?

Chemistry
2 answers:
vivado [14]3 years ago
7 0
You tryna cheat? I think it’s four so hopefully not
Naya [18.7K]3 years ago
4 0
I this it’s carrot because I’m dumb
You might be interested in
100.00 mL of 0.15 M nitrous acid (HNO2) are titrated with a 0.15 M NaOH solution. (a) Calculate the pH for the initial solution.
wolverine [178]

Answer:

a. pH = 2.04

b. pH = 3.85

c. pH = 8.06

d. pH = 11.56

Explanation:

The nitrous acid is a weak acid (Ka = 5.6x10⁻⁴) that reacts with NaOH as follows:

HNO₂ + NaOH → NaNO₂(aq) + H₂O(l)

a. At the beginning there is just a solution of 0.12M HNO₂. As Ka is:

Ka = [H⁺] [NO₂⁻] / [HNO₂]

Where [H⁺] and [NO₂⁻] ions comes from the same equilibrium ([H⁺] = [NO₂⁻] = X):

5.6x10⁻⁴ = X² / 0.15M

8.4x10⁻⁵ = X²

X = [H⁺] = 9.165x10⁻³M

As pH = -log [H⁺]

<h3>pH = 2.04</h3><h3 />

b. At this point we have HNO₂ and NaNO₂ (The weak acid and the conjugate base), a buffer. The pH of a buffer is obtained using H-H equation:

pH = pKa + log [NaNO₂] / [HNO₂]

<em>Where pH is the pH of the buffer,</em>

<em>pKa is -log Ka = 3.25</em>

<em>And [NaNO₂] [HNO₂] could be taken as the moles of each compound.</em>

<em />

The initial moles of HNO₂ are:

0.100L * (0.15mol / L) = 0.015moles

The moles of base added are:

0.0800L * (0.15mol / L) = 0.012moles

The moles of base added = Moles of NaNO₂ produced = 0.012moles.

And the moles of HNO₂ that remains are:

0.015moles - 0.012moles = 0.003moles

Replacing in H-H equation:

pH = 3.25 + log [0.012moles] / [0.003moles]

<h3>pH = 3.85</h3><h3 />

c. At equivalence point all HNO2 reacts producing NaNO₂. The volume added of NaOH must be 100mL. That means the concentration of the NaNO₂ is:

0.15M / 2 = 0.075M

The NaNO₂ is in equilibrium with water as follows:

NaNO₂(aq) + H₂O(l) ⇄ HNO₂(aq) + OH⁻(aq) + Na⁺

The equilibrium constant, kb, is:

Kb = Kw/Ka = 1x10⁻¹⁴ / 5.6x10⁻⁴ = 1.79x10⁻¹¹ = [OH⁻] [HNO₂] / [NaNO₂]

<em>Where [OH⁻] = [HNO₂] = x</em>

<em>[NaNO₂] = 0.075M</em>

<em />

1.79x10⁻¹¹ = [X] [X] / [0.075M]

1.34x10⁻¹² = X²

X = 1.16x10⁻⁶M = [OH⁻]

pOH = -log [OH-] = 5.94

pH = 14-pOH

<h3>pH = 8.06</h3><h3 />

d. At this point, 5mL of NaOH are added in excess, the moles are:

5mL = 5x10⁻³L * (0.15mol / L) =7.5x10⁻⁴moles NaOH

In 100mL + 105mL = 205mL = 0.205L. [NaOH] = 7.5x10⁻⁴moles NaOH / 0.205L =

3.66x10⁻³M = [OH⁻]

pOH = 2.44

pH = 14 - pOH

<h3>pH = 11.56</h3>
5 0
3 years ago
6. Would you describe each of these temperatures as warm, hot, or cold?
mash [69]

Answer:

b: Hot

a: Cold

c: Cold

d: Warm

e: Warm

f: Cold

g: Hot

Explanation:

:)

8 0
3 years ago
What is the significance of the Galápagos Islands to the theory of evolution
Aloiza [94]
The importance of the Galapagos to Darwin theory is chances  Darwin discovered several species of finches that varied from island to island .
A big part of reason it is so famous is because of Darwin finches.
which are 12 <span>species ,also the Darwin theory is  only gradually accepted because people don't believe in them today</span>
3 0
3 years ago
WILL GIVE BRAINLIEST NO FAKE ANSWERS PLEASE!
AleksAgata [21]

Answer:

A) (3.2g)

Explanation:

Did you reposed this? Because I remember answering this

3 0
3 years ago
Read 2 more answers
If a decrease in temperature accompanies a reaction, what occurred?
Sliva [168]

Answer:

Energy was released

Explanation:

Decrease in temperature means less energy, but the energy had to have been transferred because energy can't be destroyed or created. So if the temp. went down, energy must have been lost. (If it had been absorbed, the temp. would have gone up)

3 0
3 years ago
Read 2 more answers
Other questions:
  • What is the difference between a suspension, a colloid, a solution, and an emulsion?
    6·2 answers
  • Why would you be cautious of scientific information you hear from advertisers?
    7·1 answer
  • Nitrogen (n) atomic number = _____ atomic mass = _____ number of protons = _____ number of neutrons = _____ number of electrons
    14·1 answer
  • How to find the number of moles in a molecule of water
    8·1 answer
  • Surface water is found in oceans, lakes, reservoirs, streams, rivers,and glaciers. Lakes, rivers, and reservoirs are where human
    8·1 answer
  • What are two objects used to find density
    13·1 answer
  • What is the pressure of 2.50 moles of an ideal gas if it has a volume of 50.0 liters when the temperature is 300.0 K
    7·1 answer
  • Imagine a moving boat making waves in the middle of a pool of water. Also, imagine two observers, one behind the boat and one in
    7·1 answer
  • Which of the following elements is a metal in the periodic table​
    15·1 answer
  • Question 2 Which models of the atom from task 1 are not supported by Rutherford’s experimental evidence? For each of these mod
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!