(a)
pH = 4.77
; (b)
[
H
3
O
+
]
=
1.00
×
10
-4
l
mol/dm
3
; (c)
[
A
-
]
=
0.16 mol⋅dm
-3
Explanation:
(a) pH of aspirin solution
Let's write the chemical equation as
m
m
m
m
m
m
m
m
l
HA
m
+
m
H
2
O
⇌
H
3
O
+
m
+
m
l
A
-
I/mol⋅dm
-3
:
m
m
0.05
m
m
m
m
m
m
m
m
l
0
m
m
m
m
m
l
l
0
C/mol⋅dm
-3
:
m
m
l
-
x
m
m
m
m
m
m
m
m
+
x
m
l
m
m
m
l
+
x
E/mol⋅dm
-3
:
m
0.05 -
l
x
m
m
m
m
m
m
m
l
x
m
m
x
m
m
m
x
K
a
=
[
H
3
O
+
]
[
A
-
]
[
HA
]
=
x
2
0.05 -
l
x
=
3.27
×
10
-4
Check for negligibility
0.05
3.27
×
10
-4
=
153
<
400
∴
x
is not less than 5 % of the initial concentration of
[
HA
]
.
We cannot ignore it in comparison with 0.05, so we must solve a quadratic.
Then
x
2
0.05
−
x
=
3.27
×
10
-4
x
2
=
3.27
×
10
-4
(
0.05
−
x
)
=
1.635
×
10
-5
−
3.27
×
10
-4
x
x
2
+
3.27
×
10
-4
x
−
1.635
×
10
-5
=
0
x
=
1.68
×
10
-5
[
H
3
O
+
]
=
x
l
mol/L
=
1.68
×
10
-5
l
mol/L
pH
=
-log
[
H
3
O
+
]
=
-log
(
1.68
×
10
-5
)
=
4.77
(b)
[
H
3
O
+
]
at pH 4
[
H
3
O
+
]
=
10
-pH
l
mol/L
=
1.00
×
10
-4
l
mol/L
(c) Concentration of
A
-
in the buffer
We can now use the Henderson-Hasselbalch equation to calculate the
[
A
-
]
.
pH
=
p
K
a
+
log
(
[
A
-
]
[
HA
]
)
4.00
=
−
log
(
3.27
×
10
-4
)
+
log
(
[
A
-
]
0.05
)
=
3.49
+
log
(
[
A
-
]
0.05
)
log
(
[
A
-
]
0.05
)
=
4.00 - 3.49
=
0.51
[
A
-
]
0.05
=
10
0.51
=
3.24
[
A
-
]
=
0.05
×
3.24
=
0.16
The concentration of
A
-
in the buffer is 0.16 mol/L.
hope this helps :)
The equilibrium constant of this reaction is 1.80×10-5
Given data,
pH of solution = 2.873
Number of moles of acetic acid (m) = 0.05 moles
Volume of water (V) = 500 mL = 0.5L
So, concentration (C) = m/V in lit = 0.05/0.5 = 0.1 M
Equilibrium constant ( K ) = [tex][CH_{3} COO-][/tex]×[tex][H+_{} ][/tex]/[tex][CH_{3} COOH][/tex]
Since, acetic acid is weak acid,
So, Equilibrium constant ( K ) = [tex][H+]^{2}[/tex]/[tex][CH_{3} COOH][/tex] ....(i)
As the pH = 2.873, the [tex][H+_{} ][/tex] is antilog of -2.873 or 1.34×10-3 M.
Putting the value of concentration of [tex]H+_{}[/tex] and [tex]acetic_{} acid[/tex] in equation (i).
Equilibrium constant ( K ) = 1.80×10-5
What is weak acid ?The acid which is partially dissociates into ions on dissolving in aqueous solution is called weak acid.
Example: [tex]acetic_{} acid[/tex].
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two human actions needed to slow climate change
Answer:
using electric cars , Transitioning to energy sources that do not emit greenhouse gases, such as solar, wind, biofuels, and nuclear ☢️
Explanation:
A radioactive sample contains 1.60 g of an isotope with a half-life of 3.9 days. part a what mass of the isotope will remain after 5.6 days? (assume no excretion of the nuclide from the body.)
Answer:
.59 g
Explanation:
5.6 d / 3.9 d /half life = 1.436 half lives
(1/2)^1.436 = .3696 of original left
.3696 * 1.6 = .59 gm
Water Resources
Short Writing
Answer:
Water is one of the most precious resources the earth provides to mankind. Its use in modern age is manifold. We drink water to satisfy our thirst. We use it for domestic needs, irrigation, industrial use, transportation, power production and waste disposal. Water is universal solvent.
Thanks to our nature; it is very rich in water. About three-fourth of the earth's surface is covered with water. But only a small portion of total water resources is actually available for human use. Majority, about 97.3% is present in oceans and is salty in nature.
The fresh water constitutes only 2.7%. Out of this, inland" surface waters i.e. lakes, rivers, and ponds account for hardly 0.02%. This relatively negligible portion of the earth's water is crucially important to all form of terrestrial and freshwater aquatic life. We get water mainly from three sources;
1 Rain water.
2 Surface water
3 Ground water
elements was not easily spotted by ancient cultures?
Answer:
Bromine (Br)
Explanation:
Im assuming thats the answer you are looking for since you didnt include any options :,)
answer this question
Answer:
To test the presence of Carbon (iv) oxide in soili String ii Conical flask A white precipitate will be seen in the conical flaskCO2 in soil reacts with lime water to form calcium carbonate which is an insoluble white precipitatethere is no observable change since lime water remains colorless C02 + Ca(OH)2------------> CaCO3 + H20Explanation:
in set up A the fresh soil contains carbon (iv) oxide which reacts with lime water to form an insoluble white precipitate of calcium carbonate. In set up B carbon (iv) oxide is not present in the soil since it has been boiled the gas has been expelled. Therefore there is no observable change in B
Which of the following is an example of exercise?
a) playing chesss
b) watching basketball
c) riding your bike
Answer:
c.) riding your bike
Explanation:
Playing chess doesn't require any physical challenges, just mental
While watching basketball, you don't physiclly move
Riding a bike requires physical movement and acceliration
Therefore C is the correct answer
THURSDAY Mr. Pate's science class performed an experiment involving the chemical reaction of sodium bicarbonate (baking soda) and vinegar. Students poured 50 mL vinegar into a small bottle, then added sodium bicarbonate to a balloon. They attached the balloon to the bottle and dumped the sodium bicarbonate into the bottle. The resulting reaction produced carbon dioxide gas, which filled the balloon. Lanie hypothesized that the more sodium bicarbonate that was added to the vinegar, the bigger the balloon would get. Victor hypothesized that more than 8 g of sodium bicarbonate would cause the balloon to pop. . The Effects of Sodium Bicarbonate Levels on Gas Production in 1. Was Lanie's hypothesis correct? a Chemical Reaction Explain your answer. Trial 1 Trial 2 Trial 3 Trial 4 2. Was Victor's hypothesis correct? Explain your answer, Mass of Sodium Bicarbonate 59 7. 5 9 2003. What could the students expect Added the balloon circumference to be if Balloon 12. 5 g of sodium bicarbonate were 30 cm 38 cm 44cm 51 cm Circumference added? 2. 5 g 10 9
The balloon will burst if the volume of the balloon is less than 1.68 L since 8 g of sodium bicarbonate produces 1.68 L of carbon dioxide gas.
What is the volume of carbin dioxude produced from the chemical reaction between sodium bicarbonate (baking soda) and vinegar?The volume of carbon dioxide produced is obtained from the equation below:
[tex]CH_3COOH + NaCO_3 \rightarrow CH_3COONa + H_2O + CO_2 \\ [/tex]
1 mole of sodium bicarbonate reacts with one mole of acetic acid in vinegar to produce 1 mole of carbon dioxide.
The volume of 1 mole of carbon dioxide is 22.4 L
Moles of sodium bicarbonate in 8 g = mass/molar mass
molar mass of sodium bicarbonate = 106 g
moles of sodium bicarbonate = 8/106 = 0.075 moles
Moles of carbon dioxide produced = 0.075 moles
Volume of carbon dioxide = 0.075 × 22.4 = 1.68 L
Therefore, the balloon will burst if the volume of the balloon is less than 1.68 L.
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i need a chemistry questions about separating method
A+certain+protein+was+found+to+contain+0. 579%+zinc+by+mass. +determine+the+minimum+molecular+mass+of+the+protein
Molecular mass is the total of the atomic masses of all the atoms in the molecule. The minimum molecular mass of the protein is 11,363.64 g/mol.
What is the percent by mass?The percent by mass is the percentage composition of the mass of the solute in the mass of the solution.
As the percent by mass of zinc is 0.579 then in 100 gm of substance 0.579 gm zinc will be present. The molar mass of zinc is 65.38 u. Moles of zinc will be calculated as:
[tex]\begin{aligned} \rm moles &= \rm \dfrac {mass}{molar\; mass}\\\\&= \dfrac{0.579}{65.38}\\\\&= 0.0088\;\rm moles\end{aligned}[/tex]
So, the molecular mass of the protein will be:
[tex]\dfrac{100}{0.0088} = 11,363.64 \;\rm g/mol[/tex]
Therefore, 11,363.64 g/mol is the minimum molecular mass of the protein.
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A chemical ____ is a shorthand way to sum up what occurs in a chemical reaction
Answer:
equation
Explanation:
Which diagram shows the correct electron configuration for fluorine (F)?
A group of five short lines. The first line has an up and a down arrow above it and is labeled 1 s below. The second line has an up and a down arrow and is labeled 2 s. The third and fourth lines each have an up and a down arrow; the fifth line has an up arrow . The third, fourth, and fifth lines are bracketed with the label 2 p.
A group of five short lines. the first line has an up and a down arrow, and is labeled 1 s. The second has an up and a down arrow and is labeled 2 s. The third has an up and a down arrow, the fourth has an up, a down, and an up arrow, and the fifth has no arrow. The third, fourth, and fifth lines are bracketed and labeled 2 p.
A group of five short lines. The first line has an up, a down, and an up arrow and is labeled 1 s. The second line has an up, a down, and an up arrow and is labeled 2 s. The third, fourth, and fifth lines all have up arrows, and are bracketed with the label 2 p.
Answer:
it's A
Explanation:
The given element is, fluorine is a non-metal with symbol (F). It is a gas and belongs to the group 17 and period 2.
The atomic number of fluorine = 9
The number of electrons = 9
Answer:
its the first one... sorry for the wait was doing my homework :)
The process due to which a solid directly changes into its vapours.
Help please
Answer:
Sublimation
Explanation:
What foods of the aztec found their way into mayan cooking?.
Avocados and tomatoes were mainly eaten by the Aztecs and Maya.
How did Mayans cook their food?"Mayans cooking method includes digging a shallow pit, lining it with stones or clay balls.
Avocados and tomatoes were mainly eaten by the Aztecs and Maya, with different types of fruit. Corn was made into a kind of porridge, called atole in Mesoamerica and capita in Inca territory.
Avocados and tomatoes were mainly eaten by the Aztecs and Maya.
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ASAP PLEASEE A certain amount of Argon has 2.4x10^24 atoms. Going backwards from Atoms to Grams, how many grams of Ar would that be?
The required mass of argon in given number of atoms of argon is 155.61 grams.
What is Avogadro's number?Avogadro's number is the number of atoms which are present in 1 mole of any substance and it is equal to 6.022×10²³.
Relation between the mass and moles of any substance will be represented as:
n = W/M, whereW = given massM = molar massSo, moles of argon will be calculated by using given number of atoms as:
Moles = 2.4×10²⁴ atoms / 6.022×10²³ atoms per mole
Moles = 3.9 moles
Now mass will be:
W = (3.9mol)(39.9g/mol) = 155.61 g
Hence required mass of argon is 155.6g.
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When different parts of the oceans are heated unevenly this causes the water to?
Answer:
move in convection currents
Explanation:
When different parts of the oceans are heated unevenly this causes the water to move in convection currents.
PLEASE HELP, WILL GIVE BRAINLIEST
Answer:
See below
Explanation:
1)
.897 J / g-C * 100 gm * 120 C = 10764 J (see how the 'units' cancel out?)
2) spec heat = 963.6 J / (120 gm (90-80 C) =
963.6 / ( 120 * 10) = .803 J / g-C
from the table, this is granite
How does an increase in temperature affect a gas when the volume is fixed? (Fixed means it stays the same.)
Question 13 options:
The molecules have the same kinetic energy, the same distance between particles, and the same pressure
The molecules have a lower kinetic energy, causing a decrease in distance between particles and a decreased pressure
The molecules have higher kinetic energy, causing an increase in distance between particles which causes increased pressure
An increase in temperature at constant volume will increase the kinetic energy and the distance. Thus, option c is correct.
What is Gay-Lussac's law?Gay-Lussac's law is the ideal gas law that defines the direct relation of the temperature to the pressure of the gas at a constant volume.
With an increase in the temperature of the gas, the pressure also rises causing the distance between the particle to expand by the increase in the kinetic energy.
Therefore, option c. the kinetic energy, particle distance, and the pressure increases with tempearture rise.
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Chemistry helpppp
Which of the following amines has the highest melting point?
A. CH3CH2CH2NH2
B. CH3CH2CH2CH2NH2
C. CH3CH2CH(CH3)NH2
D. CH3CH(CH3)CH2NH2
Answer: c, and my yt is ChezBeed
Explanation:
Select the terms that describe a mind map.
detailed
detailed
graphic
graphic
colorful
colorful
textual
textual
unordered
unordered
creative
creative
linear
All these terms describe a mind map detailed graphic , colorful , unordered and creative
What is a mind map ?A mind map is a diagram used to visually organize information into a hierarchyIt shows relationships among pieces of the whole.It is often created around a single concept, drawn as an image in the center of a blank page, to which associated representations of ideas such as images, words and parts of words are added. Major ideas are connected directly to the central concept, and other ideas branch out from those major ideas.The terms that describes a mind map are detailed , as lots of detailing is done using connection symbols
Graphic , they are graphical representation of an information
Colourful , They are colourful as to make it more visually interesting .
Unordered , They information might not be in sequence and so can be called unordered also
Creative , Yes it is creative as it brings out the artist inside you and you think more ideas to make it look more beautiful and understandable .
So All these terms describe a mind map detailed graphic , colorful , unordered and creative.
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What is the Molar Mass of methylammonium bromide: Use the Periodic Table and round to the nearest hundredths.
The molar mass of methylammonium bromide is 111u.
What is molar mass?The molar mass is defined as the mass per unit amount of substance of a given chemical entity.
Multiply the atomic weight (from the periodic table) of each element by the number of atoms of that element present in the compound.
Add it all together and put units of grams/mole after the number.
Atomic weight of H is 1u
Atomic weight of N is 14u
Atomic weight of C is 12u
Atomic weight of Br is 79u
Calculating molar mass of [tex]2H_3NCH_3Br[/tex] =2(1 x3+ 14+12+ 1 x 3 +79) = 111u
Hence, the molar mass of methylammonium bromide is 111u.
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A(n)_____ is a structure that consists of dna and protein molecules coiled into a definite shape
Answer:
Double helix
Explanation:
Its like two starcaises intertwined.
Answer:
D
Explanation:
D is the answer had to find out the harder way
Match the following polyatomic lons.
(Refer to picture)
Answer:
1 Nitrate
2 sulphate
3 ammonium
4 carbonate
5 permanganate
6 phosphate
7 acetate
8 chromate
9 dichromate
10 sulphite
What is the number of collaborative relationships he creates
Each of the carbon atoms in fullerene
Answer:
answer is 60
Explanation:
Which of the following changes would result in an increase of nitrogen dioxide, NO2?
N204() <---> 2NO2(g)
AH° = 58 kJ
This can be solved according to Le C ha.tellors principle
Any change in concentration, temperature, pressure can shift the equilibriumSo
Here to increase NO_2
We need to increase the temperature or increase the concentrations of reactants
The addition of N₂O₄(g) to the system would result in an increase of nitrogen dioxide, NO₂.
The balanced equation provided shows the equilibrium between nitrogen dioxide (NO₂) and dinitrogen tetroxide (N₂O₄). According to Le Chatelier's principle, a change in conditions will cause the system to shift in a way that opposes the change. In this case, if N₂O₄ is added to the system, the equilibrium will shift to the right to consume the added N₂O₄ and produce more NO₂.
Based on the given information, the enthalpy change (AH°) for the reaction is 58 kJ. This indicates that the forward reaction (from N₂O₄ to 2NO₂) is endothermic, meaning it requires heat to proceed. Adding N₂O₄ to the system will provide more reactant molecules, increasing the concentration of N₂O₄ and causing the equilibrium to shift towards the products (more NO₂) to minimize the effect of the added N₂O₄.
Therefore, the addition of N₂O₄ to the system will result in an increase in nitrogen dioxide, NO₂, as the equilibrium shifts to the right to restore equilibrium.
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Which sample has the largest volume? the density of aluminum is 2. 7 g∙cm–3, and the density of copper is 9. 0 g∙cm–3
The sample which has the largest volume is 5 grams of aluminum.
What is density?Density is the mass of per unit volume.
Given, density of aluminum is 2.7 g.cm
The density of copper is 9. 0 g.cm
Step1: Calculate the volume
a. volume of copper of 1.0 gram
[tex]\dfrac{mass}{density} = \dfrac{1}{9} = 0.112[/tex]
Volume of copper of 5.0 gram
[tex]\dfrac{mass}{density} = \dfrac{5}{9} = 0.55[/tex]
b. aluminum of 1 gram
[tex]\dfrac{1}{2.7} = 0.370[/tex]
Aluminum of 5 gram
[tex]\dfrac{5}{2.7} = 1.851[/tex]
Thus, 5 gram of aluminum has the largest volume.
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How does the parts of a seed help it carry out its function please try to use your own words it’s for my lab..
[tex]\huge\bf\maltese{\underline{\red{J0|N}}}\maltese[/tex]
What type of sugar is characterized as best for meringue and some cakes because it dissolves more easily?
Answer:
granulated sugar
Explanation:
the rate of dissolving can be increased by mixing stirring and agitating the
solution. hope this answers your question
The asphalt in the la brea tar pits is composed of hydrocarbons, but is not considered a fossil fuel. please select the best answer from the choices provided t f
The statement is true because asphalt in the la brea tar pits can not be burnt to produce energy henece they are not fossil fuels.
What are fossil fuels?Fossil fuels are those hydrocarbons that are burnt to liberate energy. They include; crude oil, natural gas, coal, etc,
The statement is true because asphalt in the la brea tar pits can not be burnt to produce energy henece they are not fossil fuels.
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Answer:
False
Explanation:
The answer is false I just took the test , the other answer is incorrect.
How many molecules of hydrogen will be required to produce 1. 60 mol of water
The number of molecules of hydrogen will be required to produce 1.60 mol of water are 9.6×10²³.
What is the stoichiometry?Stoichiometry of the reaction gives idea about the relative amount of moles of reactants and products present in the given chemical reaction.
Given chemical reaction is:
2H₂ + O₂ → 2H₂O
From the stoichiometry of the reaction,
2 moles of hydrogen = produces 2 mole of water
1.6 moles of hydrogen = produces 1.6 mole of water
As we know that in 1 mole of any substance 6.022×10²³ entities of that substance are present.
In 1.6 mole of H₂ gas = (1.6)(6.022×10²³) = 9.6×10²³ molecules of hydrogens are present.
Hence 9.6×10²³ molecules of hydrogens are present.
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For the reactions listed below, decide whether the reaction would increase, decrease, or stay the same.
The rate of the reaction is the speed at which the reactants are used to produce the products. An increase in temperature and concentration of the reactant increases the rate of reaction.
What are the factors affecting the rate of reaction?The rate of the reaction is the speed at which the products are used to produce products. The rate increases when the concentration of the reactants in a reaction is increased. Also, the smaller grounded pieces of reactants increase the reaction rate as the surface area gets increases.
The rise in temperature and the addition of the catalyst also increases the rate of reaction as temperature and the catalysts increase the chemical reaction by increasing the speed.
When an inhibitor is added to a reaction then the rate of the reaction decreases as they inhibit the formation of the products and block the reaction pathways.
Therefore, the inhibitors decrease the rate of the reaction.
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