8)<br> As the skydiver falls to Earth, she experiences positive acceleration due to

An aqueous solution of methylamine (ch3nh2) has a ph of 10.68. how many grams of methylamine are there in 100.0 ml of the soluti

ruslelena [56]

Answer:

3.4 mg of methylamine

Explanation:

To do this, we need to write the overall reaction of the methylamine in solution. This is because all aqueous solution has a pH, and this means that the solutions can be dissociated into it's respective ions. For the case of the methylamine:

CH₃NH₂ + H₂O <-------> CH₃NH₃⁺ + OH⁻ Kb = 3.7x10⁻⁴

Now, we want to know how many grams of methylamine we have in 100 mL of this solution. This is actually pretty easy to solve, we just need to write an ICE chart, and from there, calculate the initial concentration of the methylamine. Then, we can calculate the moles and finally the mass.

First, let's write the ICE chart.

CH₃NH₂ + H₂O <-------> CH₃NH₃⁺ + OH⁻ Kb = 3.7x10⁻⁴

i) x 0 0

e) x - y y y

Now, let's write the expression for the Kb:

Kb = [CH₃NH₃⁺] [OH⁻] / [CH₃NH₂]

We can get the concentrations of the products, because we already know the value of the pH. from there, we calculate the value of pOH and then, the OH⁻:

The pOH:

pOH = 14 - pH

pOH = 14 - 10.68 = 3.32

The [OH⁻]:

[OH⁻] = 10^(-pOH)

[OH⁻] = 10^(-3.32) = 4.79x10⁻⁴ M

With this concentration, we replace it in the expression of Kb, and then, solve for the concentration of methylamine:

3.7*10⁻⁴ = (4.79*10⁻⁴)² / x - 4.79*10⁻⁴

3.7*10⁻⁴(x - 4.79*10⁻⁴) = 2.29*10⁻⁷

3.7*10⁻⁴x - 1.77*10⁻⁷ = 2.29*10⁻⁷

x = 2.29*10⁻⁷ + 1.77*10⁻⁷ / 3.7*10⁻⁴

x = [CH₃NH₂] = 1.097*10⁻³ M

With this concentration, we calculate the moles in 100 mL:

n = 1.097x10⁻³ * 0.100 = 1.097x10⁻⁴ moles

Finally to get the mass, we need to molar mass of methylamine which is 31.05 g/mol so the mass:

m = 1.097x10⁻⁴ * 31.05

<h2>m = 0.0034 g or 3.4 mg of Methylamine</h2>

3 0

3 years ago

In the following equation, ______ is being oxidized and ______ is being reduced.

Mashcka [7]

$oxidation \: number \: of \: oxygen = \\ before \: rxn = - 2 \\ after \: rxn = - 2$

$oxidation \: number \: of \: hydrogen = \\ before \: rxn = + 1 \\ after \: rxn = \\ 2x - 2 = 0 \\ x = + 1$

$oxidation \: number \: of \: carbon = \\ before \: rxn = \\ x - 6 = - 2 \\ x = 4 \\ after \: rxn = \\ x - 4 = 0 \\ x = 4$

<h2>Option A</h2>

$oxidation \: numbers \: remain \: constant \\ so \: none \:a re \: undergoing \: oxidation \: \\ nor \: reduction \:$

6 0

2 years ago

PLZ ANSWER

Taya2010 [7]

Answer:

A. The energy stored in atmospheric carbon dioxide is conserved because it is used to create new forms of energy present in decomposed plants.

Explanation:

In the carbon cycle image, the result of an industry's work releases carbon dioxide into the atmosphere (this is represented by the letter G), this carbon dioxide is stored in the atmosphere (letter C) and then absorbed by plants during the process. of photosynthesis (letter A).

The carbon cycle is constituted by the absorption of carbon dioxide by plants in the photosynthesis process. Half of this absorbed carbon is released into the atmosphere and the other half the vegetable uses to produce sugars (glycoses). By ingesting the plants, the animals ingest together the carbon to their body, being released through respiration or decomposition. Because some fungi and bacteria are responsible for the decomposition of both animals and vegetables, they ingest part of this carbon, releasing it into the atmosphere and soil. In addition to bacteria, the burning process also releases carbon dioxide into the soil and atmosphere. Vegetables, through the breathing process, also absorb carbon dioxide and release oxygen unlike animals.

4 0

4 years ago

Calculate the mass in grams of 1.72×10^24 molecules of formaldehyde. The chemical formula for formaldehyde is CH2O.

pishuonlain [190]

Answer: m= 85.8 g CH2O

Explanation: First step is convert the molecules of CH2O to moles using the Avogadro's Number.

1.72x10²⁴ molecules CH2O x 1 mole CH2O / 6.022x10²³ molecules CH2O

= 2.86 moles CH2O

Next is convert the moles of CH2O to mass using the molar mass of CH2O

2.86 moles CH2O x 30 g CH2O / 1 mole CH2O

= 85.8 g CH2O

5 0

3 years ago

An oxide of nitrogen contains 30.45 mass % N.

N76 [4]

An oxide of nitrogen contains 30.45 mass % N, if the molar mass is 90± 5 g/mol the molecular formula is N₂O₄.

<h3>What is molar mass?</h3>

The molar mass of a chemical compound is determined by dividing its mass by the quantity of that compound, expressed as the number of moles in the sample, measured in moles. A substance's molar mass is one of its properties. The compound's molar mass is an average over numerous samples, which frequently have different masses because of isotopes.

<h3>How to find the molecular formula?</h3>

The whole-number multiple is defined as follows.

Whole-number multiple = $\frac{molar mass (g/mol)}{empirical formula mass (g/mol)}$

The empirical formula mass is shown below.

Mw of empirical formula = Mw of N+ 2 x (Mw of O)

= 14.01 g/mol + 2 x (16.00 g/mol)

= 46.01 g/mol

With the given molar mass or the molecular formula mass, we can get the whole-number multiple for the compound.

Whole-number multiple = $\frac{90 g/mol }{46.01 g/mol}$ ≈ 2

Multiplying the subscripts of NO2 by 2, the molecular formula is N(1x2)O(2x2)= N2O4.

To learn more about molar mass visit:

brainly.com/question/12127540

#SPJ4

5 0

2 years ago

8) As the skydiver falls to Earth, she experiences positive acceleration due to