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
What statement discribes the relationship of voltage and current
Answer:
Explanation:
Ohm's Law. The relationship between voltage, current, and resistance is described by Ohm's law. This equation, i = v/r, tells us that the current, i, flowing through a circuit is directly proportional to the voltage, v, and inversely proportional to the resistance, r.
Place the following substances in order of decreasing vapor pressure at a given temperature: BeF2, CH3OH, OF2?
(a) OF2 > BeF2 > CH3OH
(b) BeF2 > OF2 > CH3OH
(c) BeF2 > CH3OH > OF2
(d) CH3OH > OF2 > BeF2
(e) OF2 > CH3OH > BeF2
Answer:
(b) BeF2 > OF2 > CH3OH
Explanation:
The degree and type of intermolecular forces present in a substance influences its vapour pressure considerably. The greater the magnitude and strength of intermolecular forces in the substance, the lower the vapour pressure of the substance.
BeF2 molecules are held together by weak vanderwaals forces hence BeF2 will exhibit the least degree of intermolecular interaction and have the highest vapour pressure. OF2 molecules are bound together by dipole interactions hence it will exhibit a lower vapour pressure compared to BeF2. CH3OH molecules form hydrogen bonds with water molecules hence it will exhibit the least vapour pressure among the trio.
What type of reaction is: ammonium nitrate -> dinitrogen monoxide + water?
Answer:
The thermal decomposition of ammonium nitrate to produce dinitrogen monoxide and water. This reaction takes place at a temperature of 200-260°C.
HELP PLS!! WILL GIVE BRAINLIEST What is a catalyst? A a substance that slows a reaction down without being used up itself in a reaction. B a substance that is used up while speeding up a reaction. C a reactant that is added to speed up a reaction. D a substance that increases the rate of a reaction without being used up itself in a reaction.
Answer:
D a substance that increases the rate of a reaction without being used up itself in a reaction.
Explanation:
Examples are
ammonia synthesis ==> iron
sulfuric acid manufacture ==> nitrogen(II) oxide, platinum
cracking of petroleum==> zeolites
hydrogenation of unsaturated hydrocarbons ==> nickel, platinum, or palladium
I hope it helps
Answer:
Hey there!
The correct answer would be D. "a substance that increases the rate of a reaction without being used up itself in a reaction."
Hope this helps :)
6. A diamond contains 5.0 ×10^21 atoms of carbon. What amount(moles) of carbon and what mass (grams) of carbon are in this diamond? *
a. 0.008303 and 0.0997
b. 0.008303g and 0.0997mol
c. 0.008303amu and 0.0997
d. 0.008303 and 0.0997amu
Answer:
0.008303 mol and 0.0997 g
Explanation:
From Avogadro's hypothesis, we understood that 1 mole of any substance contains 6.022×10²³ atoms.
This implies that 1 mole of carbon also contains 6.022×10²³ atoms.
Next, we shall determine the mole of carbon that contains 5.0×10²¹ atoms. This can be obtained as follow:
1 mole of carbon contains 6.022×10²³ atoms.
Therefore, Xmol of carbon will contain 5.0×10²¹ atoms i.e
Xmol of carbon = 5.0×10²¹ / 6.022×10²³
Xmol of carbon = 0.008303 mole
Therefore, 0.008303 mole of carbon contains 5.0×10²¹ atoms.
Finally, we shall determine the mass of carbon. This can be obtained as follow:
Mole of carbon = 0.008303 mole
Molar mass of carbon = 12.01 g/mol
Mass of Carbon =.?
Mole = mass /Molar mass
0.008303 = mass of carbon/12.01
Cross multiply
Mass of Carbon = 0.008303 x 12.01
Mass of Carbon = 0.0997 g.
Which of the following is an aldehyde?
Answer: [tex]CH_3CH_2CH_2CHO[/tex] has aldehyde functional group.
Explanation:
Functional groups are specific group of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules.
A. [tex]CH_3CH_2CH_2COCH_3[/tex] has ketone [tex]C=O[/tex] functional group .
B. [tex]CH_3CH_2CH_2COOH[/tex] has carboxylic acid [tex]COOH[/tex] functional group .
C. [tex]CH_3CH_2CH_2CHO[/tex] has aldehyde [tex]H-C=O[/tex] functional group .
D. [tex]CH_3CH_2CH_2COOCH_3[/tex] has ester [tex]RO-C=O[/tex] functional group .
Thus [tex]CH_3CH_2CH_2CHO[/tex] has aldehyde (CHO) group.
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.
Why does anhydrous aluminium chloride have lower melting point than anhydrous aluminium fluoride?
Answer:
Explanation:
Molecule of aluminium fluoride is more polar than molecule of aluminium chloride . It is so because fluorine is more electronegative than chlorine . On Pauling scale , the electronegativity of fluorine is 3.98 whereas that of chlorine is 3.16 . Hence in aluminium fluoride , there is stronger inter molecular bonding because of more polar nature of molecules . In aluminium chloride , there is weaker inter molecular bonding because of comparatively polar nature of molecules . Hence melting point of anhydrous aluminium fluoride is higher than that of anhydrous aluminium chloride .
Why does this experiment need a water pump?
Answer:
because the water/air needs to be pumped out.
Explanation:
hoped this helped! (just give it a 1 star if it didn't)
Triangle DEF is congruent to TriangleD'EF' by the SSS theorem. Which single rigid transformation is required to map TriangleDEF onto TriangleD'EF'? dilation reflection rotation translation
Answer:
B. reflection
Explanation:
Rigid transformations are methods involved in changing the dimensions or orientation of a given figure. The methods are; dilation, rotation, translation and reflection.
Reflection is the process in which a given figure is turned or flipped with respect to a point or line of reference.
In the given question,
ΔDEF ≅ ΔD'EF' (Side-Side-Side congruence property)
This implies that ΔDEF was reflected about point E to produce ΔD'EF'. Thus the required rigid transformation is reflection.
Answer:
Is C - Rotation
Explanation:
I have right on my test
You arrive home from class to find your roommate complaining of a headache, dizziness, and nausea. Upon further investigation you believe they may have carbon monoxide poisoning. What should be the first step taken?
Answer:
tempature of the person, check carbon levels in the house or place where the person is.
Explanation:
Which event is most likely occurring? diffusion because particles move from regions of high concentration to regions of low concentration diffusion because particles move from regions of low concentration to regions of high concentration effusion because there is a movement of a gas through a small opening into a larger volume effusion because there is a movement of a gas through a large opening into a smaller volume
Answer: c
Explanation: effusion because there is a movement of a gas through a small opening into a larger volume
What is a scientific question?
O A. One that everyone agrees on
OB. One that only scientists ask
O c. One that is answered through observation
O D. One that never changes
Answer:
O c. One that is answered through observation
I used process of elminations so
Explanation:
One that everyone agrees one doesnt mean it's accurate.
Only the one that scientists ask doesnt make sense
One that never changes and One that is answered through observation.... So C
Consider a gas in a container that can adjust its volume to maintain constant pressure. Suppose the gas is cooled. What happens to the gas particles with the decrease in temperature? What happens to the volume of the container?
Answer:
The volume will also decrease.
Explanation:
This illustration clearly indicates Boyle's law.
Boyle's law states that the volume of a fixed mass of gas is directly proportional to the absolute temperature, provided the pressure remains constant. Mathematically, it is represented as:
V & T
V = KT
K = V/T
V1/T1 = V2/T2 =... = Vn/Tn
Where:
T1 and T2 are the initial and final temperature respectively, measured in Kelvin.
V1 and V2 are the initial and final volume of the gas respectively.
From the illustration above, the volume is directly proportional to the temperature. This implies that as the temperature increases, the volume will also increase and as the temperature decreases, the volume also will decrease.
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.
Design a voltaic cell using magnesium as one of the electrodes. Magnesium can be represented as either Metal A or Metal B in the above drawing. Use metal chlorides as the solutions in the two chambers. For example, magnesium chloride, (MgCl2) will be in solution in the chamber with the magnesium electrode. Use NaNO3 in the salt bridge. Select another element for the other electrode. Explain why you selected this element. Include information about the activity of the metal you select and the need for a spontaneous reaction. Metal A: Metal B: In the drawing, 1. Label the oxidation compartment: 2. Label the reduction compartment. 3. Label the direction of the flow of electrons. 4. Label the flow of the magnesium ions. 5. Label the flow of your selected element's ions. 6. What is leaving the salt bridge in the anode compartment? 7. What is leaving the salt bridge in the cathode compartment? 8. Write the oxidation and reduction half-reactions. 9. Calculate the chemical potential of your cell. Show all of your work.
Answer:
Here's what I get
Explanation:
You haven't shown your drawing, so I will assume that Metal A is the anode and Metal B is the cathode.
I will make a galvanic cell using Mg and Zn as the metals.
I selected Zn because it is common and readily available in the lab.
Zn is lower than Mg in the activity series, so Mg should be able to displace Zn from its salts
The standard reduction potentials are:
E°/V
Zn²⁺ (aq) + 2e⁻ ⇌ Zn(s); -0.76
Mg²⁺(aq) + 2e⁻ ⇌ Mg(s); -2.38
The Mg half-reaction has the more negative potential, so it will be the oxidation half-reaction.
8 and 9. Oxidation and reduction half-reactions and cell potential
E°/V
Oxidation: Mg(s) ⇌ Mg²⁺(aq) + 2e⁻ ; +2.38
Reduction: Zn²⁺ (aq) + 2e⁻ ⇌ Zn(s); -0.76
Mg(s) + Zn²⁺ (aq) ⇌ Mg²⁺(aq) + Zn(s); +1.62
The cell potential is positive, so the reaction will be spontaneous.
Mg is the anode, so it is Metal A.
Zn is the cathode, so it is Metal B.
1. The Mg|Mg²⁺ half-cell is the oxidation compartment.
2. The Zn²⁺|Zn half-cell is the reduction compartment.
3. The electrons flow from anode to cathode in the external circuit.
4. The Mg²⁺ ions flow from the Mg through the solution to the salt bridge.
5. The Zn²⁺ ions flow from the solution to the Zn.
6. NO₃⁻ ions flow from the salt bridge into the anode compartment to balance the charge of the developing Zn²⁺ ions.
7. Na⁺ ions flow from the salt bridge into the cathode compartment to replace the charge of the depleted Zn²⁺ ions.
what is the scientific name for the layer of gas that surrounds the earth A. hydrosphere B. biosphere C. atmosphere D. lithosphere
Answer:
hydro
Explanation: hydrogen
Answer:
C. Atmosphere
Explanation:
First, let’s define each answer choice.
Hydrosphere: all of the water on Earth
Biosphere: the global ecosystem where organisms live
Atmosphere: the envelope of gases around the planet
Lithosphere: the outermost part of the Earth( the crust and upper mantle)
The question asks us to find the scientific name for the layer of gas that surrounds the Earth. The best choice is C. Atmosphere.
why can't we extract sodium from aqueous solution of sodium chloride
Answer:
As it is an aqueous solution the sodium is dissolved in the water, if you want to extract it use evaporation
Explanation:
unknown substance is heated from 10 celsius to 25 celsius, what happens at 17 Celsius
At 17 celsius ❤️
it will start to boil ❤️
#indian❤️
)Assertion: Corrosion is a beneficial process for metals. Reason : Galvanising and electroplating of metals prevent corrosion.
When N2gas is passed through water at 293k.how many moles of N2 dissolve in 1litre water
Answer: 7 milimoles of [tex]N_2[/tex] dissolve in 1 litre water.
Explanation:
Given: [tex]N_2[/tex] gas is passed through water at 293K.
Assumption :[tex]N_2[/tex] exerts a partial pressure of 0.987 bar.
Take : Henry's constant [tex]p_N_2[/tex] = 76.8 Kbar
[tex]K_H=76800[/tex]
To find : Number of moles of [tex]N_2[/tex] gas dissolve in 1 litre water.
According to Henry's law,
[tex]p_N_2=K_HX_{N_2}[/tex]
[tex]\Rightarrow\ 0.987=76800X_{N_2}[/tex]
[tex]\Rightarrow\ X_{N_2}=\dfrac{0.987}{76800}=0.0000128515625\approx1.29\times10^{-5}[/tex]
moles in 1 liter of water = [tex]\dfrac{1000}{18}=55.56\ [\text{Molar mass of }H_2O=18\ g][/tex]
Let n= moles of nitrogen
Total moles = 55.56+n
So,
[tex]X_{N_2}=\dfrac{n}{55.56+n}=1.29\times10^{-5}\\\\\Rightarrow\ 55.56\times1.29\times10^{-5}+1.29\times10^5n=n\\\\\Rightarrow\ n- 1.29\times10^5n=0.000714033\\\\\Rightarrow\ 0.999987n=0.000714033\\\\\Rightarrow\ n\approx7\text{ milimoles}[/tex]
Hence, 7 milimoles of [tex]N_2[/tex] dissolve in 1 litre water.
Determine the rate of a reaction that follows the rate law: rate = k[A]^m[B]^n, where: k = 0.2, [A] = 3 M, [B] = 3 M, m = 1, n = 2 A. 1.2 (mol/L)/s B. 27 C. 1.8 D. 5.4
[tex]7.408 \;X 10 ^ {-3} m^{-2} s^{-1}[/tex] is rate of a reaction when k = 0.2, [A] = 3 M, [B] = 3 M, m = 1, n = 2 .
What is the rate of a reaction?The rate at which the concentration of reactant or product participating in a chemical reaction alters is called the rate of reaction.
Rate of reaction = [tex]\frac{change \;in \;concentration}{time}[/tex] = (mol/litre)/time.
m= 1 and n = 2
[tex]rate = K [A] [B]^2[/tex]
[tex]0.2 = K X 3 X 3 ^2[/tex]
K = [tex]\frac{0.2 }{27 }[/tex]
K = [tex]7.408 \;X 10 ^ {-3} m^{-2} s^{-1}[/tex]
Hence, [tex]7.408 \;X 10 ^ {-3} m^{-2} s^{-1}[/tex] is rate of a reaction when k = 0.2, [A] = 3 M, [B] = 3 M, m = 1, n = 2 .
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Answer: 7.4 10-3
Explanation:
7.4 10-3 this is right ong
Which of the following has the smallest radius ? A. Br B. I C. I- D. Br-
Answer:
A. Br
Explanation:
Atomic radius increases down the group. As the increase in the attractive force of the nucleus increases owing to increase in the size of its positive charges, extra electrons are added to the shells to more than counterbalance this effect down the group hence the atomic radius becomes larger. Iodine has a larger atomic radius than bromine.
Secondly, the ionic radius of a negative ion is greater than its corresponding atomic radius since a negative ion is formed by adding a negative charge (electron) to the atom thus making it bigger. Hence the radius of I^- is greater than that of Br^-.
This means that Br atom must possess the smallest radius among the options listed.
Answer:
D
Explanation:
Br-
someone plz plz answer this hurry plz it
Answer:
b
Explanation:
This law relates a planet's orbital period and its average distance to the Sun.
The orbits of planets are ellipses with the Sun at one focus.
The speed of a planet varies, such that a planet sweeps out an equal area in equal time frames.
Answer:
These are Kepler's Laws of Planetary Motion
Explanation:
Answer:
its Keplers third law,
then first law,
then second law
Explanation:
What is the change that turns paper into ashes ? Why ? give reasons
Answer:
Chemical changeExplanation:
Burning paper is a chemical change.
Burning (or combustion ) is a high temperature chemical reaction that takes place between fuel and an oxidant(mostly oxygen)
Research has proved has taught us that ;
When paper is burned , the oxygen (from the air) combines with carbon and hydrogen in the paper turning some of it into carbon dioxide and water vapor, which waft away with carbon particulates in the smoke
I hope it helps :)
The graph compares the kinetic energies of the molecules in four gas samples. Each graph shows a normal distribution, so the average is the center. Which sample is likely to have the lowest temperature? (1 point) A B C D
Answer:
d
Explanation:
i got it right
Gas A is likely to have the lowest temperature. Hence, option A is correct.
What are molecules?The smallest particle of a substance has all of the physical and chemical properties of that substance. Molecules are made up of one or more atoms.
In a gas, the kinetic energy is directly proportional to the temperature under constant pressure and volume.
As you can see in the problem, the average of A has low kinetic energy. But the average is increasing between B, C and D.
As gas A has the lowest average kinetic energy:
Gas A is likely to have the lowest temperature
Hence, option A is correct.
Learn more about molecules here:
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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.
Julie finds a snail on the sidewalk and wants to know whether or not the snail moves throughout the day. She places a
single mark on the sidewalk next to the snail.
What will Julie use the mark for initially?
determining how fast the snail moves
acting as a standard unit of measure
determining the displacement of the snail
O acting as a reference point for detecting motion
The single mark placed on the sidewalk by Julie has been acting as the reference point for detecting the motion of the snail. Thus, option D is correct.
The snail has been the shelled animal that has been mostly residing in the resting condition with limited movement. To evaluate the movement of the snail, there has been the consideration of a point that was the starting point from the movement.
The line that has been set across the sidewalk has been acting as the reference, and the distance traveled has been calculated from that point. Thus, option D is correct.
For more information about the reference point, refer to the link:
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How would you measure the mass and weight of an object?
Answer:
Weight = mass × earth's gravitational acceleration
Explanation:
Follow the following steps to measure the mass and weight of an object:
Measure the mass of the object using an accurate measuring scale.Multiply the mass of that object with earth's gravitational acceleration which is approximately 9.8 N/kg