What quantity (moles) of NaOH must be added to 1.0 L of 1.8 M HC2H3O2 to produce a solution buffered at pH
Answer:
a) What quantity (moles) of NaOH must be added to 1.0 L of 1.8 M HC2H3O2 to produce a solution buffered at pH = pKa?
Step 1: Data given
Volume of HC2H3O2 = 1.0 L
Molarity of HC2H3O2 = 1.8 M
Ka = 1.8*10^-5
ph = pK = -log(1.8*10^-5) = 4.74
Step 2:
Use the Henderson-Hasselbalch equation.
pH = pKa + log(A-/HA)
4.74 = 4.74 + log(A-/HA)
0 = log(A-/HA)
A-/HA = 1
Consider X = moles of NaOH added (and moles of A- formed)
Remaining moles of HA = 1.8 - X
moles of A- = X
HA = 1.8 - X
X/(1.8-X) = 1
X =0.9
We have to add 0.9 mole NaOH to 1.0 L of 1.8 M HC2H3O2
To control we can do the following equation:
4.74 = 4.74 + log(0.9/0.9) = 4.74
b) What quantity (moles) of NaOH must be added to 1.0 L of 1.8 M HC2H3O2 to produce a solution buffered at pH = 4.00?
Step 1: Data given
Volume of HC2H3O2 = 1.0 L
Molarity of HC2H3O2 = 1.8 M
Ka = 1.8*10^-5
ph = 4
Step 2:
Use the Henderson-Hasselbalch equation.
pH = pKa + log(A-/HA)
4 = 4.74 + log(A-/HA)
-0.74 = log(A-/HA)
A-/HA = 0.182
Consider X = moles of NaOH added (and moles of A- formed)
Remaining moles of HA = 1.8 - X
moles of A- = X
HA = 1.8 - X
X/(1.8-X) = 0.182
X =0.277
We have to add 0.277 mole NaOH to 1.0 L of 1.8 M HC2H3O2
To control we can do the following equation:
4 = 4.74 + log(0.277/1.523)
c) What quantity (moles) of NaOH must be added to 1.0 L of 1.8 M HC2H3O2 to produce a solution buffered at pH = 5.00
Step 1: Data given
Volume of HC2H3O2 = 1.0 L
Molarity of HC2H3O2 = 1.8 M
Ka = 1.8*10^-5
ph = 5
Step 2:
Use the Henderson-Hasselbalch equation.
pH = pKa + log(A-/HA)
5 = 4.74 + log(A-/HA)
0.26 = log(A-/HA)
A-/HA = 1.82
Consider X = moles of NaOH added (and moles of A- formed)
Remaining moles of HA = 1.8 - X
moles of A- = X
HA = 1.8 - X
X/(1.8-X) = 1.82
X =1.16
We have to add 1.16 mole NaOH to 1.0 L of 1.8 M HC2H3O2
To control we can do the following equation:
5 = 4.74 + log(1.16/0.64) = 5
Explanation:
Sam washed his favorite pair of jeans. He hung the wet jeans on a clothesline outside. An hour later the jeans were dry.
Which answer best describes that happened to the water that was in the wet jeans an hour later?
State your answer and provide an explanation for your answer
A It soaked into the ground.
B It disappeared and no longer exists.
C It is in the air in an invisible form.
D It moved up to the clouds.
E It chemically changed into a new substance.
F It went up to the Sun.
G It broke down into atoms of hydrogen and oxygen.
Please help D:
Answer:
THe sun evapored the water and the wind helped dry it to.
Explanation:
A bomb calorimeter with a heat capacity of 837 J∘C contains 745 g of water. It burns 2.50 g C8H18 resulting in the temperature going from 15.0∘C to 33.8∘C. What is the value of the heat transferred (in kilojoules) by the reaction from the perspective of the system?
Answer:
74.3kJ are transeferred
Explanation:
In the bomb calorimeter, the burning of C₈H₁₈ is producing heat that is been absorbed for the calorimeter and the water.
Heat absorbed calorimeter:
837J/°C * (33.8°C-15.0°C) = 15735.6J
Heat absorbed water:
C*m*ΔT
C specific heat of water (4.184J/g°C), m is mass of water (745g), and ΔT change in temperature (33.8°C - 15°C = 18.8°C)
4.184J/g°C*745g*18.8°C = 58601.1J
Heat released by the reaction:
15735.6J + 58601.1J = 74336.7J
74.3kJ are transeferred
Show the net dipole moment (μ = 0 D) of the compounds
a) CBr4
b) cis-1,2-Dibromoethene
c) trans:-1,2-Dibromoethene
d) 1,1-Dibromoethene
Answer:
A
Explanation:
Using the equation above, the dipole moment is calculated to be 1.85 D by multiplying the distance between the oxygen and hydrogen atoms by the charge difference between them and then finding the components of each that point in the direction of the net dipole moment (the angle of the molecule is 104.5˚).
What are the factors affecting your limitations? How about possibilities?
Explanation:
My physiological make-up that governs the attributes I have and my climate, i.e. the conditions I have, are the variables influencing my limits. Biological make-up also regulates my prospects when they depend on my attributes, i.e. my ability and my environment , i.e. the conditions under which I am. This has been shown by experiments on twins, that our limits and opportunities are controlled by both genetics and environment.
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What would happen if a person who is wearing a heavy winter jacket were to
place a thermometer inside the jacket next to his or her skin? What would
happen if we took the same jacket, after it had been hanging in a closet, and
placed a thermometer inside?
Answer:
When the thermometer was placed next to the skin, it should be higher because of the heat your body gives off, and the jacket trapping the heat in, when you put it in the closet it will be cooler due to not having a heat source.
Sodium is located above potassium in Group 1 of the periodic table. If a potassium ion has a charge of +1, what is the charge on a sodium ion?
A. -1
B 0
C. +1
D +2
Answer:
C
Explanation:
It will be the same. That's what moving down a column means. The properties are going to be quite similar.
The idea that the earth is divided into a number of small plates that float on the mantle and slide,collide,and slip past each other. Law or Theories
Answer:
Theories
Explanation:
It is theories because it was a generalistee abstract or thinking generalising the principle of fact about Earth tectonic plates ,it was formulated and concluded as plate tectonic theories after many findings. The theories conclude that the Earth has an outer layer called lithosphere and lies overly a plastic layer called asthenosphere. The lithosphere is divided into several plates and they move close to each other where they diverge, converge or slip over one another.
Which statement best compares the amount of fossil fuels formed each year to the amount used each year?
Answer: The amount of fossil fuels formed is approximately the same as the amount used.
Explanation:
The amount of fossil fuels formed is approximately the same as the amount used. The amount of fossil fuels formed is much less than the amount used. The amount of fossil fuels formed is greater than the amount used.
The amount of fossil fuels formed is much less than the amount used. The correct option is C.
What is fossil fuel?Fossil fuels are deduced from the putrefaction of both animals and plants. These fuels, which can be discovered in the Earth's crust as well as encapsulate carbon and hydrogen, can be burned for energy.
Fossil fuels include coal, oil, and natural gas. The amount of fossil fuels produced is significantly less than the amount consumed.
The compounds that comprised up plankton as well as plants transform into fossil fuels after millions of years underground. Plants decompose into coal while plankton decomposes into natural gas and oil.
These resources are now extracted by humans through coal mining and the drilling of oil and gas wells on land and offshore.
Warming would certainly slow if we stopped using fossil fuels today, but removing greenhouse gases from the atmosphere will have to happen eventually.
Thus, the correct option is C.
For more details regarding fossil fuels, visit:
https://brainly.com/question/2029072
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Your question seems incomplete, the missing options are:
The amount of fossil fuels formed is exactly the same as the amount used.
The amount of fossil fuels formed is approximately the same as the amount used.
The amount of fossil fuels formed is much less than the amount used.
The amount of fossil fuels formed is greater than the amount used.
What happens when the sound waves released by a bat hit an object?
O The sound waves are diffused.
O The sound waves are reflected.
O The sound waves are refracted.
O The sound waves are absorbed.
Answer:
O The sound waves are reflected.
Explanation:
When sound waves released by a bat hits an object, the sound waves are reflected back.
Bats used sound reflection for echolocation to determine the position of nearby objects.
Also, they use it to determine the shape and size of objects.
The mechanism where bats use sound to determine location is known as echolocation. The bat picks up the reflected sound and projects the location of their targets.Answer:
B
The sound waves are reflected.
Explanation:
Assume that pure water coexists with its vapor at some temperature in a closed container. What are chemical potentials in water and in vapor and their main contributions in both phases
Calculate the mass of dinitrogen tetroxide(N2O4) that contains a billion oxygen atoms. Be sure your answer has a unit symbol if necessary, and round it to significant digits.
Answer:
23 * 10^ 9 atoms of oxygen
Explanation:
From the molecular formula of dinitrogen tetraoxide;
molar mass of dinitrogen tetraoxide = 92 g/mol
hence;
92 g of dinitrogen tetraoxide contains 4 atoms of oxygen
x g of dinitrogen tetraoxide will contain 1 * 10^ 9 atoms of oxygen
x = 92 * 1 * 10^ 9/4
x =23 * 10^ 9 atoms of oxygen
Calculate the freezing point of a solution containing 10 grams of KCl and 1100.0 grams of water. The molal freezing point depression constant (Kf) for water is 1.86
Answer:
- 0.454 °C
Explanation:
From the given information:
The mass of KCl = 10 grams
The molar mass of KCl = 74.55 g/mol
The molality can be calculated as:
[tex]Molality \ m = \dfrac{mass \ of \ KCl \times 1000}{molar \ mass \ of \ KCl \times 1100.0}[/tex]
[tex]Molality \ m = \dfrac{10 \ g \times 1000}{74.55 \ g/mol \times 1100.0}[/tex]
Molality m = 0.1219 M
For freezing point depression;
[tex]\Delta T_R = i \times k_f \times m[/tex]
The van't Hoff's Factor (i) for KCl = 2
The molar depression of freezing point constant [tex]k_f[/tex] = 1.86° C/m
∴
[tex]\Delta T_R = 2 \times 1.86 \times 0.1219[/tex]
[tex]\mathbf{\Delta T_R = 0.454^0\ C }[/tex]
However, the freezing point of water is known to be = 0°C
Therefore, the freezing point of the solution
= 0 °C - 0.454 °C
= - 0.454 °C
Item 10
What color do acids turn litmus paper?
yellow
red
pink
blue
Answer:
red
Explanation:
blue litmus paper turns red under acetic conditions and red lettuce paper turns blue under basic and alkaline conditions with the color change occurring over the PH range the neutral litmus paper is purple
The answer is red.
took the test.
Define dynamic equilibrium.
a) no reactants react no products are formed the rate of the forward reaction
b) is faster than the rate of the reverse reaction the rate of the reverse reaction
c) is faster than the rate of the forward reaction the rate of the forward reaction
d) equals the rate of the reverse reaction
Answer:
d) The rate of forward reaction equals the rate of the reverse reaction
Explanation:
A dynamic equilibrium is attained when the rate of forward reaction is the same as reverse reaction. It occurs majorly in a reversible reaction. Thus, no change occurs in the reaction.
The process can be control by the immediate removal of the product as it is formed. This ensure that the reaction stops when all reactants are used up.
an area of high pressure occurs when
Answer:
A high-pressure area, high, or anticyclone, is a region where the atmospheric pressure at the surface of the planet is greater than its surrounding environment. Winds within high-pressure areas flow outward from the higher pressure areas near their centers towards the lower pressure areas further from their centers.
Explanation:
Sulfur dioxide and oxygen react to form sulfur trioxide during one of the key steps in sulfuric acid synthesis. An industrial chemist studying this reaction fills a 50.0L tank with 14. mol of sulfur dioxide gas and 2.6 mol of oxygen gas, and when the mixture has come to equilibrium measures the amount of sulfur trioxide gas to be 1.6 mol. Calculate the concentration equilibrium constant for the reaction of sulfur dioxide and oxygen at the final temperature of the mixture. Round your answer to 2 significant digits.
Answer:
Explanation:
From the given information:
The equation for the reaction can be represented as:
[tex]2SO_2 + O_2 \to 2SO_3[/tex]
The I.C.E table can be represented as:
2SO₂ O₂ 2SO₃
Initial: 14 2.6 0
Change: -2x -x +2x
Equilibrium: 14 - 2x 2.6 - x 2x
However, Since the amount of sulfur trioxide gas to be 1.6 mol.
SO₃ = 2x,
then x = 1.6/2
x = 0.8 mol
For 2SO₂; we have 14 - 2x
= 14 - 2(0.8)
= 14 - 1.6
= 12.4 mol
For O₂; we have 2.6 - x
= 2.6 - 1.6
= 1.0 mol
Thus;
[SO₂] = moles / volume = ( 12.4/50) = 0.248 M ,
[O₂] = 1/50 = 0.02 M ,
[SO₃] = 1.6/50 = 0.032 M
Kc = [SO₃]² / [SO₂]² [O₂]
= ( 0.032²) / ( 0.248² x 0.02)
= 0.8325
Recall that; the equilibrium constant for the reaction [tex]2SO_2 + O_2 \to 2SO_3[/tex] = 0.8325;
If we want to find:
[tex]SO_2 + \dfrac{1}{2}O_2 \to SO_3[/tex]
Then:
[tex]K_c = (0.8325)^{1/2}[/tex]
[tex]\mathbf{K_c = 0.912}[/tex]
Since no temperature is given to use in the question, it will be impossible to find the final temperature of the mixture.
Which of the following rock will form if it is broken into sediment then emulsified over a long period of time?
Sedimentary rock
Magma rock
Metamorphic rock
Igneous rock
PLEASE HELP!! 74 POINTS
An igneous rock has small, dark crystals. Which statement also accurately describes this rock?
It is an intrusive rock.
It has a coarse texture.
It was found on Earth’s surface.
It was formed from slow cooling.
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Which is one factor that contributes to the formation of polar, temperate, and tropical zones?
the angle of the Sun’s rays
the direction of seasonal winds
the presence of prevailing winds
the movement of wind near a mountain
Answer:
It was formed from slow cooling.
the angle of the Sun’s rays
Explanation:
Answer:
D. It was formed from slow cooling.
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How and why do ionic bonds form? Check all of the boxes that apply
lonic bonds form between metal atoms and other metal atoms.
Ionic bonds form between metal atoms and nonmetal atoms
The more electronegative atoms transfer one or more electrons to the less electronegative atom
The less electronegative atoms transfers one or more electrons to the more electronegative atom,
The metal atom forms a cation and the nonmetal atom forms an anion
The attraction between ions with the same charge forms an ionic bond,
The attraction between ions with an opposite charge forms an ionic bond.
BLO
I lo
DONE
Elo
Yous
Answer:
✔️Ionic bonds form between metal atoms and nonmetal atoms.
✔️The less electronegative atoms transfers one or more electrons to the more electronegative atom
✔️The metal atom forms a cation and the nonmetal atom forms an anion.
✔️The attraction between ions with an opposite charge forms an ionic bond.
Explanation:
Ionic bond refers to the bond formation which occurs when there is complete and permanent transfer of electrons from one metal atom to another non-metal atom. The metals, which are electropositive (less electronegative) loose their electrons while the non-metals, which are less electropositive (more electronegative) gain the electrons.
When the metal atom looses electrons, they form cations(become positively charged) while non-metal atom forms anions (become negatively charged). When the opposite charges attract each other, they form ionic bond.
Answer:
✔️ Ionic bonds form between metal atoms and nonmetal atoms.
✔️ The less electronegative atoms transfers one or more electrons to the more electronegative atom.
✔️ The metal atom forms a cation and the nonmetal atom forms an anion.
✔️ The attraction between ions with an opposite charge forms an ionic bond.
Lamark goes to a bowling alley to test his belief that rolling a bowling ball slowly will result in knocking down more pins. He gently rolls his bowling ball towards the bowling pins lined up at the end of the lane. The bowling ball stops in the middle of the lane without striking the pins. Which statement below best explains what happened?
Answer:
The ball's kinetic energy is transforming to potential energy.
Explanation:
the ball is stopping resulting in potential energy
What is the relationship between gravity and the size of an object?
the bigger the object the more weight of the planet or gravity is acted upon if
Give the spectator ions for the reaction that occurs when aqueous solutions of H2SO4 and KOH are mixed.
a. OH- and K+
b. H+ and SO4-2
c. K+ and SO4-2
d. H+ and OH-
e. No spectator ions are present.
Answer:
Option C. K⁺(aq) and SO₄²¯(aq)
Explanation:
We'll begin by writing the ionic equation between H₂SO₄ and KOH.
This is illustrated below:
In solution, H₂SO₄ and KOH will dissociate as follow
H₂SO₄ (aq) —> 2H⁺ (aq) + SO₄²¯ (aq)
KOH (aq) —> K⁺ (aq) + OH¯ (aq)
Thus, aqueous H₂SO₄ and KOH will react as follow:
H₂SO₄ (aq) + 2KOH (aq) —> K₂SO₄ (aq) + 2H₂O (l)
Ionically:
2H⁺(aq) + SO₄²¯(aq) + 2K⁺(aq) + 2OH¯(aq) —> 2K⁺(aq) + SO₄²¯(aq) + 2H₂O (l)
The spectator ions are those ions that appear on both sides of the equation.
From the above ionic equation, the spectator ions are:
K⁺(aq) and SO₄²¯(aq)
1. How does thermal energy move between objects?
A. It moves from objects of lower mass to objects with higher mass
B. It moves from objects of higher mass to object with lower mass
C. It moves from objects of lower temperature to objects with higher temperature
D. It moves from objects of higher temperatures to objects with lower temperature
Answer:
D
Explanation:
Answer:
D
Explanation:
So. Radiation happens when heat moves as energy waves, called infrared waves, directly from its source to something else.... When the heat waves hits the cooler thing, they make the molecules of the cooler object speed up.
Which of the following represents the equation for volume?
L x H
L x W
L x W x H
W x H
Answer:
L× W×H
Please mark me as brainlist.Answer:
The correct answer is L x W x H :)
Object A has a mass of 12g and a volume of 8cm3. object B has a mass of 20g and a volume of 8cm3 . which object has a greater density and by how much
Answer:
Object B has a density of 2.5 g/cm³ which is greater than object A by 1 g/cm³
Explanation:
Since we know that the formula for density is d=m/v, we can divide each mass by its corresponding volume to find the densities
12/8=1.5
20/8=2.5
So we know that object B has a greater density than object A by 1 g/cm³ (gram per cubic centimeter). Also the standard unit for density is kilograms per cubic meter but I used gram per cubic centimeter since they were the given units. 1cm=100m, 1000g=1km
You are trying to confirm that your bottle of hydrochloric acid is supposedly 1.0 M, as labeled. You decided to perform a titration with 1.3 M sodium hydroxide and 100 mL of your hydrochloric acid. You expect to use 77 mL of sodium hydroxide to neutralize the acid, but in the experiment it actually took 89.13 mL of NaOH to reach the endpoint. What is the actual concentration of the hydrochloric acid?
Answer:
The actual concentration of the hydrochloric acid is 1.2M
Explanation:
The formula to be used here is that of concentration (popularly used during titration);
CₐVₐ/CbVb =nₐ/nb
where Cₐ is the concentration of acid (supposed to be 1.0 M but unsure)
Vₐ is the volume of acid (100 ml)
Cb is the concentration of base (1.3 M)
Vb is the volume of base (89.13 ml)
nₐ is the volume of acid
nb is the volume of base
The equation for the reaction described in the question is
HCl + NaOH ⇒ NaCl + H₂O
we can see from the above equation the ratio of the number of moles for both the acid and the base is 1:1
Thus;
Cₐ × 100/1.3 × 89.13 =1/1
Cₐ = 1.3 × 89.13/100
Cₐ = 1.2M
The actual concentration of the hydrochloric acid is 1.2M
Using Gizmo ,describe the main use for each fuel Coal: Petroleum: In each case, what is the end product of burning the fossil fuel,and where does it go? Help is for today
Answer:
See explanation
Explanation:
Coal is primarily used for electricity generation. The burning of coal leads to emission of gases such as oxides of carbon, oxides of sulphur, oxides of nitrogen and water vapour. All these go straight into the atmosphere.
Petroleum is primarily used as transportation fuels. The burning of petroleum oils mostly leads to the emission of oxides of carbon and sulphur together with water vapour into the atmosphere.
Please select the word from the list that best fits the definition
Represents a range of responses to a question:
Caption
Legend/Key
Scale
Answer:
The answer is B(scale)
Explanation:
Since the question asked about a range, the scale would be the most logical answer since scales are used to measure.
Answer:
the answer is C.
Explanation:
The growth of a certain plot was measured over a period of more than a month. How many centimeters did the plant grow between day 10 and day 30. 0.5 cm 1.0 cm 1.5 cm 2 cm
Answer:
2cm would be the answer I think