Answer:
7.41 × 10⁻⁵
Explanation:
Let's consider the basic dissociation reaction of trimethylamine (CH₃)N).
(CH₃)N + H₂O = (CH₃)NH⁺ + OH⁻
According to Brönsted-Lowry, in this reaction (CH₃)N is a base and (CH₃)NH⁺ is its conjugate acid. The pKb for (CH₃)N is 9.87. We can calculate the pKa of (CH₃)NH⁺ using the following expression.
pKa + pKb = 14
pKa = 14 - pKb = 14 - 9.87 = 4.13
Then, we can calculate the acid dissociation constant for (CH₃)NH⁺ using the following expression.
pKa = -log Ka
Ka = antilog - pKa = antilog -4.13 = 7.41 × 10⁻⁵
The lattice-like structure of a metal consists of negative metal ions in a "sea" of electrons.
O True
O False
Answer:
True
Explanation:
A solution at 25 degrees Celsius has a pH of 4.48. What is the pOH of this solution?
0.978
3.17
9.52
10.51
Answer:
The answer is C = 9.52
Explanation:
I took the test
The pOH of a solution that has a pH of 4.48 at 25°C is 9.52. Details about pH can be found below.
What is pH?pH refers to the power of hydrogen in a substance while the pOH refers to the power of hydroxyll ions. The pH of a solution ranges from 0 - 14 indicating the strength of acidity and alkalinity.
The relationship between the pH and pOH in a solution is given as follows:
pH + pOH = 14
According to this question, a solution at 25 degrees celsius has a pH of 4.48. The pOH of the solution is calculated as follows:
4.48 + pOH = 14
pOH = 14 - 4.48
pOH = 9.52
Therefore, the pOH of a solution that has a pH of 4.48 at 25°C is 9.52.
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Answer:
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You can find the speed on a distance-versus-time graph by finding the slope of the line.
True
False
Consumers must eat other organisms
for energy. Which organisms
are consumers in this food chain?
Answer:
frog-snake+-Eagle
Explanation:
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A quantity of gas was cooled from 323 K to 273 K. Express this temperature
difference in degrees Celsius and Kelvins. What do these temperatures
represent about the gas particles? Which temperature scale is a more accurate
depiction of this representation? Explain briefly.
Answer:
give more details
Explanation:
A mixture of fuel and is injected into a cylinder fitted with a piston. The initial volume is 0.37 L. After the mixture is ignited, gaseous products are formed and 1885 J of energy is released by the reaction. 311 J of the released energy is lost as heat to the surroundings. To what volume would the gases expand against a constant pressure of 1.036 atm, if the remainig energy is converted to work to push the
Answer:
The gases will expand to a volume of 2.37 L
Explanation:
Gases are able to do work when they expand or compress against an external constant pressure.
This work done by gases when they expand or compress against a constant external pressure is known as pressure-volume work or PV work.
The formula for calculating the work done by gases when they compress or expand against a constant pressure is given as W = PΔV
Where ΔV is change in volume given as V2 - V1
Where V2 is final volume, V1 is initial volume
By convention, W can either be negative or positive. When work is done by the system (ΔV > 0), W is negative and when work is done on the system (ΔV < 0), W is positive.
In the gas mixture above, W = PΔV
Remaining energy, W = (1885 - 311) J = 1574 J
P = 1.036 atm = 1.036 × 760 mmHg = 787.36 mmHg
ΔV = V2 - V1
ΔV = V2 - 0.37
1574 = 1.036 (V2 - 0.37)
V2 - 0.37 = 1574/787.36
V2 - 0.37 = 1.999 L
V2 = 1.999 + 0.37
V2 = 2.369 L
Therefore, the gases will expand to a volume of 2.37 L
Select the correct answer.
Your friend Keith has been in a dating relationship for six months. His personality has changed in these months. He looks unhappy and rarely smiles. He avoids the company of friends. On the rare occasions you have seen him, his face appears bruised. You suspect that Keith may be in an abusive relationship. What should you do in this case?
A.
avoid talking to Keith
B.
confront his dating partner
C.
encourage Keith to speak up and report abuse
D.
advise him to tolerate the abuse, as difficulties are a part of life
Which of the following are reasons the ocean marine biomes are a challenging place for organisms to live? Choose all that apply.
Question 13 options:
some areas are extremely dark and deep
high waves can be rough and powerful
all of the organisms have to live without sunlight
organisms have to be able to live in extremely salty conditions
In an ecosystem, the reason that ocean marine biomes are a challenging place for organisms to live because they have to be able to live in extremely salty conditions.
What is an ecosystem?Ecosystem is defined as a system which consists of all living organisms and the physical components with which the living beings interact. The abiotic and biotic components are linked to each other through nutrient cycles and flow of energy.
Energy enters the system through the process of photosynthesis .Animals play an important role in transfer of energy as they feed on each other.As a result of this transfer of matter and energy takes place through the system .Living organisms also influence the quantity of biomass present.By decomposition of dead plants and animals by microbes nutrients are released back in to the soil.
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A student is trying to develop questions to help identify an unknown biome. Which of the following questions would provide helpful information to identify an unknown biome? Select ALL that apply. A. Is sunlight an abiotic factor in this biome? B. What is the average temperature of this biome? C. How much precipitation does this biome receive each year? D. What adaptations do plants and animals have to survive in this biome? E. Is the biome located near an ocean? F. Do plants and animals live in this biome? G. Does carbon cycle in this biome?
Answer:
I think the answer is C. D. And F.
Explanation:
I’m sorry if I’m wrong :(
Answer:
I think the answer is BCD and maybe F
Explanation:
half equation for oxygen to oxide ions, aluminium ions to aluminium, magnesium to magnesium ions
PLSSS HELP ME THIS IS FOR SIENCE PLLLLSSSSS
The passing of heat through a material is called ________.
A. vibration
B. conduction
C. radiation
D. convection
Answer:
Conduction
Explanation:
I took the course
Answer:
B. conduction
what will the sun become when it dies
Answer:
It will become a red giant
Explanation:
When the sun runs out of its hydrogen fuel and the hydrogen atoms are combined together to make helium atoms, it expands into a red giant, which is made up of helium atoms and gases.
Why do some states have more representatives than other states? A Because states have different land areasBecause states have different land areas B Because states joined the U.S. in different yearsBecause states joined the U.S. in different years C Because all states have the same number of representativesBecause all states have the same number of representatives D Because states have different populationsBecause states have different populations
Answer:
D
Explanation:
The number of representatives depends on the population size. A state with fewer residents will have less representatives than a state with more residents.
to the nearest gram, what is the mass of of one spoonfull of sugar? g
Answer:
the mass of one spoonful of sugar to nearest gram is 10g
When does phenolphthalein turn pink?
in the presence of a base
in the presence of an acid
when it is in a neutral solution
when it is reacting with a metal
Answer:
A. In the Presense of a base
Explanation:
Just took the test from Edgunuity
Phenolphthalein turns pink in color in the presence of a base. Therefore, option A is correct.
What is phenolphthalein and its use?Phenolphthalein is a chemical compound that is often used as an acid-base indicator. It is colorless in acidic solutions and pink or red in basic solutions.
Phenolphthalein is often used in titrations to determine the endpoint of a reaction between an acid and a base. It can also be used as a laxative or in forensic investigations to test for the presence of blood.
Phenolphthalein has a chemical formula of C₂₀H₁₄O₄ and is synthesized by reacting phthalic anhydride with phenol in the presence of a strong acid catalyst. It is also used as a pH indicator. phenolphthalein has been found to have potential health benefits, such as reducing the risk of cancer, improving digestion, and reducing inflammation. Therefore, option A is correct.
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The primary structure of a protein is determined by
A. The order of amino acids in the protein.
B. The amino acid composition.
C. The hydrogen bonding that gives the protein three dimensional shape.
D. The intertwining of protein molecules to form a “functional” protein.
Answer: I believe the answer is A. The order of amino acids in the protein.
Explanation:
How many liters of phosphine are produced when 34 L of hydrogen reacts with an excess of phosphorus under STP?
Answer:
22.67 L of PH₃
Explanation:
The balanced equation is:
[tex]P_4 (s) + 6H_2(g) \to 4PH_3(g)[/tex]
From the equation:
[tex]34 L \times \dfrac{1 \ mol \ of H_2 }{22.4 \ L \ H_2} \times \dfrac{4 \ mol \ of \ PH_3}{6 \ mol \ H_2} \times \dfrac{22.4 \ L \ PH_3}{1 \ mol \ PH_3}[/tex]
= 22.67 L of PH₃
Cómo escribir el símbolo Theta
If a 50.0 g piece of glass is heated from 20.0°C to 40.0°C, how many joules of heat are added? The specific heat of glass is 0.50 J/g°C.
Answer:
500J (joules)
Explanation:
since heat is is the product of mass, change in temperature, and specific heat, the solution can be found from the equation q = mcΔt, heat is 50 * .5 * 20 = 500J
A gas has a pressure of 1.5 atm at 100K. If the pressure changes to 6 atm, what is the new temperature be?
Answer:
400k
Explanation:
volume is constant
P1/T1=P2/T2
1.5/100=6/T2
T2=(100×6)/1.5
T2=400k
PLEASE NO BOTS lol
Ethyne or acetylene is also used in cutting torches. The acetylene is combined with pure oxygen producing a flame with a temperature of 6332 °F or 3500 °C. The combustion of acetylene in the presence of excess oxygen yields carbon dioxide and water:
2C2H2 (g) + 5O2 (g) --> 4CO2 (g) + 2H2O (l)
Calculate the value of ΔS° for this reaction.
A. +689.3 J/mol K
B. +432.4 J/mol K
C. -432.4 J/mol K
D. -122.3 J/mol K
The correct answer is
C. -432.4 J/mol K
In which type of reaction does a reactant compound break down in order to form
two or more compounds or elements in the product?
a. Synthesis
b. Decomposition
c. Combustion
d. Single Displacement
Answer:
decomposition is the answer it helped also explanation of it is below this answer
Explanation:
In a decomposition reaction, one reactant breaks down into two or more products. This is the reverse of a synthesis reaction. Replacement reactions occur when elements switch places in compounds
True or False When one side of a molecule is electronegative (δ-) and the other side of the
molecule is electropositive (δ+), it is said to have a dipole moment. Water has
a dipole moment.
Answer:
True; When one side of a molecule is electronegative (δ-) and the other side of the
molecule is electropositive (δ+), it is said to have a dipole moment.
Explanation:
A dipole moment exists in a molecule as a result of differences in the electronegativity values between the atoms of the elements involved in the chemical bonding.
When a strogly electronegative atom such as oxygen or chlorine is chemically bonded to a less electronegative or an electropositive atom such as hydrogen, there is an uneven sharing of the electrons involved in the bonding. The more electronegative atoms tends to draw the shared electrons mostly to themselves. This induces a partially negative charge (δ-) on them while leaving the electropositive atoms with a partially positive charge (δ+).
Water is an example of a molecule having a dipole moment. The oxygen atoms are more electronegative than hydrogen and as such draw the shared electrons to themselves more, inducing a partial positive charge (δ+) on the hydrogen atoms while they themselves develop a partial negative charge (δ-).
18. If I need to dilute a 12 M hydrochloric acid solution and make 300 mL of a 0.100 solution, how
much of the 12 M hydrochloric acid do I need?
Explanation:
A 300-ml of 0.100M HCl solution contains
0.100M HCl = (0.100 mol HCl/L) × (0.300 L)
----> 0.03 mol HCl
So we need to find the volume of 12M HCl solution that contains 0.03 mol HCl
0.03 mol HCL = (12 mol HCl/1 L)×V
or
V = (1 L × 0.03 mol HCl)/(12 mol HCl)
= 0.0025 L
= 2.5 ml
So you need 2.5 ml of 12M HCl to be diluted with distilled water to 300 ml in order to get a 0.100M HCl solution.
what is chemical name of ghee
Answer. Chemical formula of ghee: (C17H33 Coo)3 C3H5 • Chemical Reaction: (C17H31Coo)3 C3H5 + 3H2 (C17H33 Coo)3 C3H5
Which is/are used in nuclear reactors to absorb neutrons?
A. heavy nuclei
B. critical mass
C. chain reactions
D. control rods
Answer:
A. heavy nuclei
Explanation:
They absorb neuyrons in order to hain stability.
Can you tell me any chemical reaction that occur due to kinetic energy
Answer:
The molecules in gasoline (octane, the chemical formula shown) contain chemical energy. This energy is transformed into kinetic energy that allows a car to race on a racetrack.
Uranium is an element with three naturally occurring isotopes: 238U, 235U, and 234U. This means that 238U, which has a mass number of 238 has _______more than 235 u which has a mass number of 235.
Answer:
The correct answer is - neutrons.
Explanation:
Uranium has various isotopes found naturally that are three 238U, 235U, and 234U. Uranium has an atomic number of 92 which means there are 92 protons and 92 electrons in the atomic structure.
Isotopes have the same number of protons but a different number of neutrons that can vary from 141 to 146. U-238 has 146 neutrons in the nucleus, whereas 235 U has 143 neutrons.
The U- 238 has more neutrons than U- 235. Atomic mass is the sum total of the nucleons or protons and neutrons.
What are Isotopes?
They are the different variants of the same molecules which have the same number of protons but the different number of neutrons.
Atomic mass is the sum total of the nucleons or protons and neutrons. The atomic number of Uranium is 92, the rest of the mass comes from neutrons.
Therefore, the U- 238 has more neutrons than U- 235.
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For 2-methylbutane, the AH° of vaporization is 25.22 kJ/mol and the
AS° of vaporization is 84.48 J/mol K. At 1.00 atm and 201 K, what is
the AG° of vaporization for 2-methylbutane, in kJ/mol?
Answer:
ΔG° = ΔH° - TΔS°
ΔG° = 25.22-(201 )(0.08448)
ΔG° = 8.24 kJ/mol
The standard free energy is obtained as 8.2 kJ/mol.
We know that; ΔG° = ΔH° - TΔS° where;
ΔG° = standard free energy
ΔH° = standard enthalpy
T = temperature
ΔS° = standard entropy
Hence substituting the values;
ΔG° =25.22 kJ/mol - (201 K * 84.48 J/mol K)
ΔG° = 25.22 * 10^3 J/mol - 16980.5 J/mol
ΔG° = 8.2 kJ/mol
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