Answer:
Explanation:ifk
If the pH of a weak acid solution is 2.500 and the solution has a concentration of 0.100M, what is the Ka of the weak acid HA?
Answer:
The Kₐ of the weak acid is 1.033×10⁻⁴
Explanation:
The dissociation of a weak acid in aqueous solution is limited to about 5 to 10%
The acid dissociation reaction is given as follows;
HA (aq) + H₂O (l) → H₃O⁺(aq) + A⁻ (aq)
Given that the pH = 2.5, we have
pH = -log₁₀[H₃O⁺] = 2.5
∴ [H₃O⁺] = 10^(-2.5) = 0.0031623
[tex]K_a = \dfrac{[H_3O^+][A^-]}{[HA]}[/tex]
Kₐ = [H₃O⁺][A⁻]/[HA] = (0.0031623^2)/(0.1 - 0.0031623) = 1.033×10⁻⁴
The acid dissociation constant, Kₐ for weak acid is very low as obtained
[O.01]Which of these is the location where sea floor spreading occurs? abyss guyot ocean trenches mid-ocean ridges
Answer:
D. mid-ocean ridges
Explanation:
The location where seafloor spreading occurs is at mid-ocean ridges. Therefore option 4 is correct.
Mid-ocean ridges are underwater mountain ranges that extend through the Earth's oceans. They are formed by the tectonic plates diverging or moving apart from each other.
As the plates separate, magma rises from the mantle to fill the gap, creating new oceanic crust. The molten material solidifies to form new seafloor, which then moves away from the ridge in opposite directions.
Seafloor spreading is a key process in plate tectonics and the continuous renewal of the Earth's crust.
It leads to the expansion of the ocean basins and the formation of new crust, contributing to the overall movement and reshaping of the Earth's lithosphere.
Therefore, the correct answer is option 4: mid-ocean ridges.
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12. Classify the following as conduction, convection or radiation. a. A steel mug kept near a stove becomes hot after some time. b. The metal handlebars of a bicycle are colder than plastic hand grips. c. Some people get sunburn when they go out in the sun for a long time. d. The paper kept above a candle flame starts burning after some time.
A - convection
B - conduction
C - radiation
D - convection
why the filament of bulb has high melting point
Answer:
The filament of a bulb has a high melting point because of the heat generated inside the bulb.
Explanation:
When electricity is concentrating and run through a bulb, it starts to generate heat. Leave it on long enough and it will start to build up a lot of heat. Have you ever tried touching a light bulb when it has been all day? It's scorching to the skin.
Since electricity generates heat, the bulb's filament has to have a high melting point so it doesn't melt, destroy the bulb, and leave you light-less. If the filament has a high melting point, then it is able to withstand heat generated by electricity and provide you light.
PLEASE HELP ASAP The molecular weight of oxygen gas (O2) is 32 g/mol. What is the mass of a single oxygen atom? 2.66 x 10-23 g 3.13 x 10-1 g 1.06 x 10-23 g 5.31 x 10-23 g
Answer:
5.31×10¯²³ g.
Explanation:
Data obtained from the question include:
Molar weight of O2 = 32 g/mol
Mass of 1 oxygen atom =..?
From Avogadro's hypothesis, we understood that 1 mole of any substance contains 6.02×10²³ atoms.
This implies that 1 mole of O2 also contains 6.02×10²³ atoms.
1 mole of O2 = 32 g
The mass of 1 atom of O2 can be obtained as follow:
32 g of O2 contains 6.02×10²³ atoms.
Therefore Xg of O2 will contain 1 atom i.e
Xg of O2 = 32/6.02×10²³
Xg of O2 = 5.31×10¯²³ g
Therefore, the mass of a single oxygen atom is 5.31×10¯²³ g.
The mass of a single oxygen atom is 5.31 x 10⁻²³ grams. Therefore, option D is correct.
The molecular weight of oxygen gas is 32 g/mol. To find the mass of a single oxygen atom, divide the molecular weight by Avogadro's number (6.022 x 10²³ atoms/mol).
Avogadro's number (6.022 x 10²³) represents the number of particles (atoms, molecules, or ions) in one mole of a substance.
To find the mass of a single oxygen atom, divide the molecular weight of oxygen gas by Avogadro's number:
Mass of a single oxygen atom = (32 g/mol) / (6.022 x 10²³ atoms/mol)
Simplifying the expression:
Mass of a single oxygen atom = 5.31 x 10⁻²³ g
Therefore, the mass of a single oxygen atom is 5.31 x 10⁻²³ grams.
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Which electrons are the valence electrons of the atom?
O A. The electrons closest to the nucleus
O B. The electrons that have lost their charge
O C. The electrons farthest away from the nucleus
O D. The electrons that have entered the nucleus
Answer:
[tex]\boxed{C}[/tex]
Explanation:
The electrons farthest away from the nucleus are the valence electrons of an atom.
The valence electrons are the electrons orbiting in the last shell around the nucleus.
Answer:
Option C
Explanation:
The electrons that are the farthest away from the nucleus are valence electrons. These are electrons are present in the outermost shell which is also called valence shell.
If he wants to model a longitudinal wave that carries more energy, how should he move the end of the spring?
Answer:
they won
Explanation:
What is the oxidation number of carbon in CO2
Answer: Since oxygen is in group 6 on the periodic table, its valency is
2 −
and hence so is its oxidation number.
But there are 2 oxygen atoms for each carbon atom so the total negative charge due the oxygen is
4 −
But since a molecule must have a net charge of zero in the free form, it implies that the oxidation number of the carbon atom must then be
+ 4
What type of reaction does this equation represent?
2I4O9(s) → 4I2(s) + 9O2(g)
Answer:
2I4O9_4I +9O
Explanation:
Complex compound (
I
4
O
9
) is broken down to form
I
2
and
O
2
Answer:
Decomposition
Explanation:
Because it went from one compound to two elements.
HELP ME OUT PLZ Today is the deadline
Answer:
Option (1)
Explanation:
When two or more substances are chemically combined in a fixed proportion of mass, substance formed is a compound.
Properties of a compound are different from the properties of the elements from which the compound is formed.
If Magnesium (Mg) is burned in the presence of Oxygen (O₂), Magnesium oxide (MgO) is formed.
Properties of MgO are different from Mg and O₂ because MgO is a COMPOUND.
Option (1) will be the answer.
The mass number of a chromium atom is 52 and it has 24 protons. How many neutrons does this atom have? 24 28 76 80
The number of protons and neutrons together makes the total atomic mass of the element. The atom of chromium has 28 neutrons. Thus, option b is correct.
What is an atomic mass?An atomic mass is the property of an element that defines the number of protons and neutrons of the atom placed in a periodic table. The atomic mass is represented at the lower half of the atomic symbol.
The atomic mass is the sum of the neutrons and the protons that are held together in the nucleus of the atom as a concentrated mass. The atomic number is given as,
Atomic number = number of protons + number of neutrons
Given,
The atomic mass of chromium = 52
Number of protons = 24
Substituting values above:
52 = 24 + number of neutrons
number of neutrons = 52-24
= 28
Therefore, the number of neutrons of a chromium atom is 28.
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Answer: option b, 28
What is meant by 1m length
Answer:
The metre is defined as the length of the path travelled by light in a vacuum in 1/299 792 458 of a second.
Which type of graph is best used to show how a measured quantity changes over time?
Box and whisker plot
Line graph
Circle graph
Histogram
Explain this
When a small piece of glowing sodium is placed inside a gas jar filled with chlorine gas, the sodium continues to burn brightly but when the gas is replaced by argon gas, the glowing sodium becomes extinguished.
Answer:
Because Argon is a inert gas
Explanation:
Inert gases don't take place in any experiments
Answer:
Below.
Explanation:
The sodium reacts strongly with the chlorine to form NaCl and the heat of reaction continues the brightness, whereas it does not react with the inert gas argon and soon cools down.
example of nobel gas
Answer:
helium , krypton,xenon,radon, argon are noble gasses
how is impure copper refined by electrolysis
Answer:
By giving electricity to copper compound solution.
Explanation:
Electrolysis is one of the major way of refined copper. The copper containing solution has two electrodes.i) positive electrodes called anode. ii) negative electrodes called cathode. When electricity is pass into the copper containing solution electrolysis process is starts and impure copper is formed in anode and pure copper is formed in cathode.
So, We can get pure copper in cathode through electrolysis.
I Hope this will be helpful for you.
If this is helpful for you .Then choose this answer as brainliest answer.
Hope it helps.
If you have any query, feel free to ask.
In nuclear fusion, small fragments, like atomic nuclei, neutrons, and other particles, form when energy is released. TRUE FALSE
Answer:
TRUE
Explanation:
It is true because along with energy, nuclear fusion releases other particles as well. This can include neutrons or atomic nuclei. An example of this is when hydrogen isotopes (D + T) fuse together to create helium it also releases a neutron. Thus D+T --> He + n + energy.
Therefore the answer is TRUE.
A scuba diver’s air tank contains oxygen, helium, and nitrogen at a total pressure of 205 atmospheres. The partial pressure of nitrogen is 143 atmospheres, and the partial pressure of helium is 41 atmospheres. What is the partial pressure of oxygen in the tank?
answer is 20
explanation: total Pressure = 205
partial pressure of N = 143
partial pressure of He = 41
total pressure = partial pressure of N + partial pressure of O + partial pressure of He
partial pressure of O = 205 - 185 = 20
Answer:
20
Explanation:
Which products are the same in both the copper carbonate and the calcium carbonate if they react with hydrochloric acid in different reactions (shown above
Explanation:
the carbonate and the hydrochloric acid are the same in both reactions as products
In an experiment, 125ml of H2 is collected over water at 27C and barometric pressure of 753 torr. the vapor pressure of water at 27C is 26.74 what is the partial pressure of H2?
Answer:
Partial pressure of H₂ = 0.9556 atm
Explanation:
Given:
Barometric pressure = 753 torr
Vapor pressure of water = 26.74 torr
FInd:
Partial pressure of H₂
Computation:
Partial pressure of H₂ = Barometric pressure - Vapor pressure of water
Partial pressure of H₂ = 733 - 26.74
Partial pressure of H₂ = 726.26 torr
1 atm = 760 torr
So,
Partial pressure of H₂ = 726.26/760
Partial pressure of H₂ = 0.9556 atm
Consider the half reaction below.
Which statement best describes what is taking place?
Chlorine is losing electrons and being oxidized. Chlorine is losing electrons and being reduced. Chlorine is gaining electrons and being oxidized. Chlorine is gaining electrons and being reduced.
Answer:
balancing of charges of both sides
Answer:
A
Explanation:
A...............................
The cell potential of an electrochemical cell is positive. What does that tell
you about the redox reaction?
A. The reduction part of the reaction occurs at the anode.
B. The oxidation part of the reaction occurs at the cathode.
C. The reaction is spontaneous.
O D. The reaction is nonspontaneous.
Answer:
A. The reduction part of the reaction occurs at the anode
Answer:
A
Explanation:
Based on the information that is given, which atom in the table has the highest mass?
The question is incomplete, the complete question is;
Atom Number of protons Number of electrons Number of neutrons
1 39 39 52
2 40 40 50
3 39 39 54
4 40 40 51
Based on the information that is given, which atom in the table has the highest mass?
a. 1
b. 2
c. 3
d. 4
Answer:
c
Explanation:
The relative atomic mass is given as; number of protons + number of neutrons. If we take the relative atomic mass of each of the options;
1) 39 +52 = 91
2) 40+50 = 90
3) 39 + 54 = 93
4) 40 + 51 = 91
Thus 3 has the highest mass as seen above, hence the answer given.
The figure shows a graph of Allison’s walk to school. She follows the black vectors to get to her school. Which if the following best describes her walk?
Answer:
Allison walks 5 blocks west and 3 blocks south.
Explanation:
Vectors have both magnitude and direction. The attached figure shows the graph of Allison’s walk to school. She follows the black vectors to get to her school.
The first vector on the horizontal axis points towards west and there are 5 blocks. Initially, she walks 5 blocks in west direction.
The second vector points in the negative vertical axis. It means that she walks 3 block in south direction.
Hence, the correct option is (D) i.e. Allison walks 5 blocks west and 3 blocks south.
Given isotope of nitrogen (N) contains 7 electrons, 7 protons and 8 neutrons. - What is the mass number - What is its atomic number
Answer:
Mass no= 16
and atomic no= 7
Explanation:
mass number is equals to number of protons + number of neutrons .
atomic number is equals to number of protons .
Which of the outer planets is MOST like Earth? How?
Answer:
venus
Explanation:
hope i helped
brainliest pls pls pls
-Zylynn
Answer: I would say that Saturn is most like Earth. Not only does it have moons, like Earth, but the atmosphere is also denser like Earth. It also has windstorms, granite they are much more intense than Earth’s, but they do indeed happen. Saturn also has hydrogen gas; this gas is here on Earth supporting life in our ocean. Therefore, there is a chance that the conditions on Saturn could provide the essentials for there to be life.
How many electrons can the n = 4 shell hold? 8 16 32 64
Answer:
32Explanation
n = 4
Now,let's find the number of electrons:
[tex]2 {n}^{2} [/tex]
plug the value
[tex] = 2 \times {4}^{2} [/tex]
Evaluate the power
[tex] = 2 \times 16[/tex]
Multiply the numbers
[tex] = 32[/tex]
Hope this helps...
best regards
Electrons are the sub-particles present in atomic shells. The (Principal Quantum Number) n = 4 shell of the atom can hold 32 electrons in it. Thus, option c is correct.
What is Principal Quantum Number?Principal Quantum Number (n) is defined as the distance of the electron from the nucleus and its energy in the atom. It can also be said to know the position of the electron in the energy level along with the orbital size.
The Principle Quantum Number, n = 4 depicts the fourth shell or energy level of the atom that can hold a specific number of electrons in it.
The electrons present in the shell or the energy level are determined by,
2n²
Here, n = 4
Substituting the values above,
= 2 (4)²
= 2 (16)
= 32
Therefore, the n = 4 energy shell can contain 32 electrons.
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Which of the following is represented by the number of significant figures in a quantity? A) estimation B) precision C) accuracy D) scientific notation
Answer: the answer is B estimation
Explanation:
i just took a test
The one that is represented by the number of significant figures in a quantity is scientific notation. The correct option is D.
What is scientific notation?Scientific notation is a method of expressing numbers that are either too large or too small to be written in decimal form.
In the United Kingdom, it is known as scientific form, standard index form, or standard form.
The proper scientific notation format is an x 10b, where an is a number or decimal number with an absolute value greater than or equal to one and less than ten, or 1 |a| 10. b is the power of ten required for scientific notation to be mathematically equivalent to the original number.
Scientific notation is represented by the number of significant figures in a number.
Thus, the correct option is D.
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A large scuba tank with a volume of 18 L is rated for a pressure of 220 bar. The tank is filled at 20 °C and contains enough air to supply 1860 L of air to a diver at a pressure of 2.37 atm (a depth of 45 feet). Was the tank filled to capacity at 20 °C?
Answer:
Yes, at 20 °C the tank was filled to full capacity
Explanation:
Given;
let initial pressure, P₁ = 2.37 atm
let initial volume, V₁ = 1860 L
let final pressure, P₂ = 220 bar = 217.123 atm
let final volume, V₂ = ?
Subject the air volume (1860 L ) at 2.37 atm to the tank rating (220 bar)
Ideal law is given by;
PV = nRT
At a fixed mole and gas temperature, the equation becomes;
P₁V₁ = P₂V₂
V₂ = (P₁V₁) / P₂
V₂ = (2.37 x 1860) / 217.123
V₂ = 20.3 L
After subjecting the air volume to tank rating, the volume of the air at 220 bar is 20.3 L which is greater than tank volume (18 L).
The extra 2.3 L can be assumed to be compressed gas volume due to the given (lower) temperature.
Thus, at 20 °C the tank was filled to full capacity.
Indicators change color when an acid and a base are mixed together. The change in color most likely indicates that a chemical change has occured. a physical change has occured. a new acid has been produced. a new base has been produced.
Answer:
a chemical change
Explanation:
a physical change is mostly identified even without indicators i.e candle wax about forming a new acid or base I guess we have to include a ph scale to ascertain since the salt can be acidic but not necessarily an acid
Answer: The answer is A, a chemical change has occurred
Explanation:
I’m just a jenious