NH3 is a weak base, and it reacts with water to form NH4+ and OH- ions in a reversible reaction. That also means that NH3 is also a good proton acceptor.
The equation for this reaction is:
NH3 + H2O ⇔ NH4+ + OH-
The Ka expression for this reaction would be:
Ka = [NH4+][OH-] / [NH3]
But since NH3 is a base, it's more appropriate to talk in terms of base dissociation constant (Kb):
Kb = Kw / Ka
Where Kw is the ion product of water, Kw = [H+][OH-].
Given Kb = 10^-4.75, the equilibrium concentrations of [OH-] can be calculated using the ICE table method, which stands for Initial, Change, Equilibrium. Let’s suppose that 'x' is the equilibrium concentration of OH-, then the concentration of NH4+ will also be 'x', and the concentration of NH3 will be 0.1-x.
Then, the Kb expression becomes:
Kb = [NH4+][OH-] / [NH3] = x*x / (0.1-x)
Setting this equal to the given Kb value and solving for x:
10^-4.75 = x^2 / (0.1-x)
From this equation, we find that x = [OH-] = 5.6234*10^-4 M.
Then we can calculate pOH:
pOH = -log[OH-] = -log(5.6234*10^-4) = 3.2502
Remember that pH + pOH = 14 at 25°C, we can find the value of pH:
pH = 14 - pOH = 14 - 3.2502 = 10.7498
So the pH of the 0.1 M NH3 solution is approximately 10.75.
The available options A, B, C and D in the question do not provide the exact calculated value 10.75 for the pH. However, in a multiple choice context, the answer would be A (9.3) as it is the closest option to 10.75.
Please note that this is a simplification. The true value may vary depending on the precision of the Kb value provided and other conditions like temperature.
Answer: b. Fiona is correct because the diagram shows two individual simple machines.
Explanation:
A mechanical device using which we can change the direction or magnitude of force applied is known as simple machine.
For example, in the given diagram there are two individual simple machines.
The machine helps in changing the direction or magnitude of force applied by the man. As a result, it becomes easy for him to carry different things easily from one place to another.
Thus, we can conclude that the statement Fiona is correct because the diagram shows two individual simple machines, is correct.
A positive reaction for Molisch's test is given by almost all carbohydrates (exceptions include tetroses & trioses). It can be noted that even some glycoproteins and nucleic acids give positive results for this test (since they tend to undergo hydrolysis when exposed to strong mineral acids and form monosaccharides).
Taking into accoun the ideal gas law, The volume of a container that contains 24.0 grams of N2 gas at 328K and 0.884 atm is 26.07 L.
An ideal gas is a theoretical gas that is considered to be composed of point particles that move randomly and do not interact with each other. Gases in general are ideal when they are at high temperatures and low pressures.
The pressure, P, the temperature, T, and the volume, V, of an ideal gas, are related by a simple formula called the ideal gas law:
P×V = n×R×T
where P is the gas pressure, V is the volume that occupies, T is its temperature, R is the ideal gas constant, and n is the number of moles of the gas. The universal constant of ideal gases R has the same value for all gaseous substances.
Explanation:
In this case, you know:
P= 0.884 atm
V= ?
n= 0.857 moles (where 28 g/mole is the molar mass of N₂, that is, the amount of mass that the substance contains in one mole.)
R=0.082
T= 328 K
Replacing in the ideal gas law:
0.884 atm×V= 0.857 moles× 0.082 ×328 K
Solving:
V= 26.07 L
The volume of a container that contains 24.0 grams of N2 gas at 328K and 0.884 atm is 26.07 L.
15 moles.Explanation:Hello,In this case, the undergoing chemical reaction is:Clearly, since carbon and oxygen are in a 1:1 molar ratio, 15 moles of carbon will completely react with 15 moles of oxygen, therefore 15 moles of oxygen remain as leftovers. In such a way, since carbon and carbon dioxide are also in a 1:1 molar ratio, the theoretical yield of carbon dioxide is 15 moles based on the stoichiometry:Best regards.
Answer: 25 g
Explanation: Given:
Original amount (N₀) = 100 g
Number of half-lives (n) = 11460/5730 = 2
Amount remaining (N) = ?
N = 1/2ⁿ × N₀
N = 1/2^2 × 100
N = 0.25 × 100
N = 25 g
Answer: 7.8125 g
Explanation: Given:
Original amount (N₀) = 500 g
Number of half-lives (n) = 9612/1602 = 6
Amount remaining (N) = ?
N = 1/2ⁿ × N₀
N = 1/2^6 × 500
N = 0.015625 × 500
N = 7.8125 g
0
23 437
rating
0.857 moles (where 28 g/mole is the molar mass of N₂, that is, the amount of mass that the substance contains in one mole.)
×328 K
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