Answer:
1.51 × 10⁻⁵
Explanation:
Step 1: Given data
pKa value: 4.82
Step 2: Write the reaction for the acid ionization of butanoic acid, HC₄H₇O₂
Butanoic acid is a weak acid that ionizes according to the following equation.
HC₄H₇O₂(aq) ⇄ C₄H₇O₂⁻(aq) + H⁺(aq)
The acid ionization constant for this reaction is Ka
Step 3: Calculate the value of the ionization constant for butanoic acid
We will use the following expression.
pKa = -log Ka
Ka = antilog -pKa = antilog -4.82 = 1.51 × 10⁻⁵
Approximately 220 million tires are discarded in the U.S. each year. These tires present a disposal problem because they take up space, harbor pests, and have been known to catch fire. One tire can generate about 250,000 BTUs (1 BTU = 3 x 10 -4 kWh) when it is burned. The average American home consumes about 10,000 kWh of electricity per year. How many tires would be needed to meet the annual electricity demand of ten homes for one year if the production of electricity from tires is 50% efficient?
Answer:
2667 tires are needed to meet the demand of ten homes for one year.
Explanation:
According to the Second Law of Thermodynamics, only a part of generated energy when tires are burned can be utilized due to irreversibilities associated with finite temperature differences. The energy from a tire that can be transformed into electricity ([tex]E_{out}[/tex]), measured in kilowatt-hours, is estimated by definition of efficiency:
[tex]E_{out} = \eta \cdot E_{in}[/tex]
Where:
[tex]\eta[/tex] - Efficiency, dimensionless.
[tex]E_{in}[/tex] - Energy liberated by burning, measured in kilowatt-hours.
Given that [tex]\eta = 0.5[/tex] and [tex]E_{in} = 75\,kWh[/tex], the amount of energy per year generated by a tire is:
[tex]E_{out} = 0.5\cdot (75\,kWh)[/tex]
[tex]E_{out} = 37.5\,kWh[/tex]
Now, the amount of tires needed to meet the demand of then homes for one year is:
[tex]n = \frac{(10\,homes)\cdot \left(10000\,\frac{kWh}{home} \right)}{37.5\,\frac{kWh}{tire} }[/tex]
[tex]n = 2666.667\,tires[/tex]
2667 tires are needed to meet the demand of ten homes for one year.
plz help me the plz argent
Answer:
Baking powder is combination of baking soda and an edible acid such as tartaric acid. When its added to water it reacts to form carbon dioxide. This carbon dioxide produces wet dough and makes cake soft and spongy
Atomic number of a Carbon atom is 6. How many electrons does it have?
1) Describe enthalpy and the role specific heat plays in the formula. 2) Explain the significance of the sign of the enthalpy value (+ or -) . Provide a specific example. 3) Explain Collision theory and describe the two factors required for a chemical reaction to occur. 4) Connect each of these circumstances to the rate of a reaction. Explain how the change in circumstances could be implemented in a lab and describe the predicted outcome: - Increased temperature - Decreased solution concentration - Increased surface area - Speeding up the reaction without being involved in the reaction. 5) Analyze Le Chatelier’s principle. 6) Based on this theory, what is the overriding guide to predicting outcomes when changes are imposed upon a reaction. What is the impact on equilibrium?
Explanation:
5) Le Chatelier's principle says, when in a reversible reaction any of the concentration or temperature or pressure are changed, then the equilibrium shifts such a way to nullify the changes occurred. (hope you get it)
6) 1.change in concentrationR ======= P
if concentration of reactant R is increased then eqm shifts towards the one with lower concentration ,that is product P.
forward direction is favoured.
2.Change in temperatureif the above's reaction is endothermic, that is temp of product is low. So increasing temperature in such case reaction goes towards product.
forward direction is favoured.
If reaction is exothermic ,temp of reactant is more. So increasing temperature in such case, reaction goes towards reactants.
forward direction is favoured
........ plz brainliest my answer I definitely write you the complete explanation asap!
The central Xe atom in the XeF4 molecule has ________ unbonded electron pair(s) and ________ bonded electron pair(s) in its valence shell.
Answer:
XeF4 has two unbounded pairs of electrons and four bonded pairs of electrons on its valence shell
Explanation:
XeF4 is a square planar compound with Xe-F distance of about 1.95 angstroms. The compound has six electron pair domains on its outermost shell. Four bond pairs occupy four corners of a square to give a square planar geometry while two electron pairs are found above and below the plane of the square.
Hence the molecule is square planar.
What are the parts of the water system? Label the water wheel to show the matter and forms energy that flow through the system.
Answer:
Source, processing and distribution are the components of water system.
Explanation:
There are three parts of water system i. e. the source, the processing and distribution. Water is extracted from a source such as underground water, lake or river etc. After extraction this water is transported to the processing unit where it can be purified and after purification it is distributed to all places where it is needed. Potential energy is a form of energy that flows through this water system because the water is extracted from a depth and we know that depth and height refers to potential energy.
How many moles of CO2 are produced when 2.5 moles of O2 react according to the following equation?
C3H8 + 5O2 ? 2FeO + 3SO2
Answer:
1.5 moles of CO₂ are produced
Explanation:
Based on the chemical equation:
C₃H₈ + 5O₂ → 3CO₂ + 4H₂O -The reaction of the question is wrong-
5 moles of oxygen reacts per mole of propane, C₃H₈, to produce 3 moles of CO₂ and 4 moles of water.
If 2.5 moles of oxygen react and, 5 moles of oxygen produce 3 moles of CO₂, moles of CO₂ produced are:
2.5 moles O₂ * (3 moles CO₂ / 5 moles O₂) =
1.5 moles of CO₂ are produceddefine the term solubility,saturated solution, solubility product constant
Answer:
Hey!I will try to help with the ones I know.
solubility is a means of comparing the extent to which different solutes can dissolve in a particular solvent at a definite temperature.
A saturated solution of a solute at a particular temperature is one which contains as much solute as it can dissolve at that temperature in the presence of undissolved solute particles....
This is what I know I hope it helps you
Which is a symbol that represents SI units for temperature?
0 °C
g
OL
OF
Answer:
0 °C
Explanation:
Answer:
0 C
Explanation:
In an experiment, shining which type of light on a strip of metal would be least likely to
produce the photoelectric effect?
ultraviolet light
dim blue light
bright red light
bright yellow light
Answer:
bright red light on edge
In an electromagnetic spectrum, bright red light would produce photoelectric effect on a strip of metal .
What is an electromagnetic spectrum?The electromagnetic spectrum consists of electromagnetic radiation consists of waves made up of electromagnetic field which are capable of propogating through space and carry the radiant electromagnetic energy.
The radiation are composed of electromagnetic waves which are synchronized oscillations of electric and magnetic fields . They are created due to change which is periodic in electric as well as magnetic fields.
In vacuum ,all the electromagnetic waves travel at the same speed that is with the speed of air.The position of an electromagnetic wave in an electromagnetic spectrum is characterized by it's frequency or wavelength.They are emitted by electrically charged particles which undergo acceleration and subsequently interact with other charged particles.
Learn more about electromagnetic spectrum,here:
https://brainly.com/question/23727978
#SPJ2
Please someone can help with this answer?
Answer:
6,000kg/m3
Explanation:
6.00g/1cm3 x 1kg/1000g x 1cm3/0.000001m3
= 6.00kg/0.001m3
= 6,000kg/m3
A sample of V weighs 61.9 grams. Will a sample of He that contains the same number of atoms weigh more or less than 61.9 grams
Answer:
Weigh less than 61.9 g
Explanation:
The symbol V represents the element Vanadium and He represents Helium.
Generally, 1 mol of any atom contains 6.022 * 10^23 atoms. This means we have to find the number of moles of each elements.
For V;
Number of moles = Mass / Molar mass = 61.9 / 50.94 = 1.215 mol
1 mol = 6.022 * 10^23 atoms
1.215 = x
Number of atoms = 6.022 * 10^23 * 1.215 =7.317 * 10^23
For He;
Since equal number of moles contain equal number of atoms;
Number of mol of He = 1.215 mol
Number of moles = Mass / Molar mass
Mass = Molar mass * Number of moles = 4 * 1.215 = 4.86 g
This means it would weigh less.
What function does adding a coefficient in a chemical equation serve?
Answer:
coefficients increase the products to increase the efficiency of the reaction.Coefficients balance the equation with respect to the law of conversation of mass. coefficients also increases the reactants to help the reaction proceed.
Which one of the following is the highest temperature? A. 302 K B. 38 degrees Celsius C. 96 degrees Fahrenheit D. None of the above E. The freezing point of water
Answer:
If it's cold it's going to be E, and if it's the hottest it's going to be C.
Explanation:
What element is being oxidized in the following redox reaction? Sn 2+(aq) + NH4 +(aq) → Sn(s) + NO3 -(aq)
Answer:
Nitrogen
Explanation:
Hello,
In this case, for the given reaction we first need to assign the oxidation state for each species in the chemical reaction:
[tex]Sn ^{2+}(aq) + (N^{-3}H^+_4)^ +(aq) \rightarrow Sn^0(s) + (N^{5+}O_3^{2-})^ -(aq)[/tex]
In such a way, since the tin is decreasing its oxidation state it is being reduced whereas the nitrogen is being oxidized as its oxidation state is being increased from -3 to +5.
Best regards.
The element which is oxidized in the redox reaction shown below is Nitrogen.
Sn²⁺(aq) + NH⁴⁺(aq) → Sn(s) + NO₃⁻(aq)
In this scenario, the oxidation state of Sn changed from +2 to 0 while the
oxidation state of Nitrogen changed from -3 to +5. The Nitrogen(N) present
in the equation experienced an increase in the oxidation state which means
it was oxidized.
The Tin(Sn) on the other hand experienced a reduction in the oxidation state
which means it was reduced.
Read more on https://brainly.com/question/25544428
How can you determine which bond in a structure is more polar without using an electronegativity table?
Answer:
How can you determine which bond in a structure is more polar without using an electronegativity table?
Explanation:
When we say something is polar, it has a very specific meaning. It means that there is a spatial separation of charges, or a dipole moment. In the simplest case, this is given by:
μ=Qr
Where μ is the dipole moment, Q is the charge on each pole (equal and opposite) and r is the distance between the charges.
Anything with charges can have a dipole moment, and therefore be polar. In chemistry, we typically worry about whether or not two things are polar:
Bonds
Molecules
Bond Polarity
Chemists are concerned with the polarity of bonds because polarity affects the character of the bond - the more polar the bond is, the more it behaves like an ionic bond. The less polar, the more it behaves like a covalent bond. This has implications for everything from naming rules to reactivity, but all you need to know for this problem is:
All bonds between two atoms are polar, unless the atoms are identical.
(This is including whatever else the atoms may be bonded to). The only question after that is "how polar is the bond," and that is where tables of electronegativity come in. Using an arbitrarily defined scale, we can measure the relative polarity of bonds by comparing the difference in electronegativity between the two elements.
Molecule Polarity
For molecules, polarity isn't quite so simple. We know that all bonds between dissimilar atoms are polar, but in a molecule, sometimes the dipole moments add up to form a net dipole moment of zero. This is a little bit difficult to explain if you don't have a mathematics and physics background that includes vectors and summations of forces/moments.
If you do, then when I say something like:
The net dipole moment for a molecule is equal to the sum of dipole moments over each bond.
It will make sense to you. If you don't, then you have to get a little more creative. I tell my students to imagine that there are ropes connecting each outer molecule to the central molecule, along each bond. Then imagine pulling each rope towards the side that is more electronegative (has a higher electron density). The more polar the bond, the harder you pull on the rope. Then imagine whether the molecule moves. If the forces balance, it stays put, so the net dipole moment is zero and it is not polar. If it does move, there was a net dipole moment, so it is polar.
This works pretty well - as long as you can visualize the molecular geometry. That's the hard part. To know how the bonds are oriented in space, you have to have a strong grasp of Lewis structures and VSEPR theory. Assuming you do, you can look at the structure of each one and decide if it is polar or not - whether or not you know the individual atom electronegativity. This is because you know that all bonds between dissimilar elements are polar, and in these particular examples, it doesn't matter which direction the dipole moment vectors are pointing (out or in).
Let's look at each one, using wikipedia's geometric pictures.
BrF5
BrF5
As you can see, there is a lone pair at the bottom (this is a square pyramidal geometry). The net dipole moment will be pointing "up", which makes this a polar molecule.
PBr5
PBr5
This one has a trigonal bipyramidal geometry, with each bond symmetrically opposed to each of the others. If you add up the vectors, they result in a net dipole moment of zero. Therefore, it is non-polar.
EDIT: As ron points out in the comments below, this is not really a binary molecular compound, and in reality forms an ionic crystal structure with PBr4+ and Br−. I don't think the author of the question intended you to worry about that, but if they did, the answer is still "non polar," although we wouldn't really call it a "molecule" any more.
CCl4
CCl4
Carbon tetrachloride has a tetrahedral geometry, and all the dipole moment vectors cancel. Therefore, it is non-polar.
XeF2
XeF2
This one is linear - no net dipole moment, so it is non-polar.
XeF4
enter image description here
I could only find the ball-and-stick model for this one. It is square planar - there is a lone pair of electrons (not shown) on each "face" of the square on Xe. There is no net dipole moment, so it is also non-polar.
Out of all of these, the only polar molecule is BrF5 (the first one).
If the net dipole moment is zero, it is non-polar. Otherwise, it is polar.
Suppose that you wanted to prepare a acetate ion/acetic acid buffer solution with a pH of 4.35. What is the value 34 Marks: 2 off [A l/IHA) for the correct buffer solution for this event? The Ka for acetic acid is 1.8 x 10 5.
a. 0.39
b. 0.407
c. 0.372
d. 4.74
Answer:
b. 0.407
Explanation:
Acetic acid / Acetate ion is a buffer (Mixture of a weak acid, acetic acid, with its conjugate base, acetate ion) with pKa = -log Ka = 4.74.
The simplest way to determine the pH of a buffer is using Henderson-Hasselbalch formula:
pH = pKa + log [Conjugate base] / [Weak acid]
For acetic buffer with pH = 4.35:
4.35 = 4.74 + log [A⁻] / [HA]
-0.39 = log [A⁻] / [HA]
0.407 = [A⁻] / [HA]
Thus, right option is:
b. 0.407Which of the following compounds would be more soluble in 1 M NH3 than in pure water? BaSO 4 AgBr Pbl 2 BaF 2 Ca(OH) 2
Answer:
AgBr
Explanation:
The salt, AgBr has a very low solubility is pure water. However, it has a high solubility in 1 M NH3. The reason behind this higher solubility of AgBr in 1 M aqueous ammonia solution is the formation of a complex as shown below;
AgBr(s) + 2NH3(aq) ----> [Ag(NH3)2]^+(aq) + Br^-(aq)
The formation of this linear silver diammine complex accounts for the higher solubility of AgBr in 1 M aqueous ammonia solution.
Where is the majority of Earth’s water found?
glaciers
Answer:
Oceans
Explanation:
The majority of water is found in the ocean where it contains 96.5% of earths water. :)
There is an electrolytic cell in which Mn2+ is reduced to Mn and Sn is oxidized to Sn2+.
A. Write an equation for the half-reaction occurring at each electrode. Express your answers as chemical equations separated by a comma. Identify all of the phases in your answer.
B. What minimum voltage is necessary to drive the reaction? Vmin =
Answer:
-1.05 V
Explanation:
At the anode;
Sn(s) -----> Sn^2+(aq) + 2e
At the cathode;
Mn^2+(aq) + 2e ------> Mn(s)
Given that it is an electrolytic cell,
E°cell= E°cathode - E°anode
But;
E°cathode= -1.19 V
E°anode= -0.14 V
E°cell= -1.19-(-0.14)
E°cell= -1.05 V
Therefore
Vmin = -1.05 V
Knowing what intermolecular forces are, if I took two electrons (negatively
charged particles) and tried to put them near each other, what would happen?
Explain your reasoning.
Answer:
They will repel each other.
Explanation:
According to Coulomb's law, the force between two chargee is directly proportional to the product of the magnitude of the both charges and inversely proportional to their distance apart.
The force of attraction between electric charges may be attractive or repulsive in nature. When two negative charges are placed in close proximity to each other, they repel each other because like charges repel each other.
What is the mass of a bar of aluminum with length 5.3cm, width 0.32 cm and height 2.34cm? The density of aluminum is 2.70g/cm3.
Answer:
mass = 10.72 gExplanation:
Density of a substance can be found by using the formula
[tex]Density = \frac{mass}{volume} [/tex]
Making mass the subject we have
[tex]mass = Density \times volume[/tex]
From the question
Density = 2.70 g/cm³
We assume that the aluminum is a cuboid
and volume of a cuboid is given by
Volume = length × width × height
length = 5.3 cm
width = 0.32 cm
height = 2.34 cm
Volume = 5.3 × 0.32 × 2.34 = 3.97 cm³
Substitute the values into the above and solve for the mass
We have
mass = 2.70 × 3.97
We have the final answer as
mass = 10.72 gHope this helps you
Describe what is meant by synthesis. How do the functions of analysis, synthesis, and evaluation relate to each other
Answer:
New element formed by combination of reactants.
Explanation:
Synthesis refers to the production of a new product from the combination of two or more reactants. Analysis, synthesis, and evaluation are related to each other because in synthesis a new product is formed while in analysis, we examine the structure of the new product in detailed and in evaluation, we assess the quantity of a new product. So analysis and evaluation gives a lot of information about the product which is formed in synthesis.
A 100.0 mL buffer solution is 0.175 M in HClO and 0.150 M in NaClO. What is the pH after addition of 0.090 g of NaOH?A
Answer:
pH = 7.51
Explanation:
The pKa of the HClO/NaClO buffer is 7.46. To determine the pH of this buffer we can use H-H equation:
pH = pKa + log [A⁻] / [HA]
pH = 7.46 + log [NaClO] / [HClO]
Where [] is molarity -or moles- of each compound
Initial moles of HClO and NaClO:
HClO: 0.100L * (0.175mol / L) = 0.0175 moles HClO
NaClO: 0.100L * (0.150mol / L) = 0.0150 moles NaClO
Now, HClO reacts with NaOH producing NaClO:
HClO + NaOH → NaClO + H₂O
The moles of NaOH that reacts (Molar mass: 40g/mol) are:
0.090g * (1mol / 40g) = 0.00225 moles NaOH.
That means after the reaction, 0.00225 moles of HClO are consumed and 0.00225 moles of NaClO are produced.
And after the reaction, moles are:
Final moles:
HClO: 0.0175 mol - 0.00225 mol = 0.01525 moles
NaClO: 0.0150 mol + 0.00225 mol = 0.01725 moles
Replaing in H-H equation:
pH = 7.46 + log [0.01725moles] / [0.01525moles]
pH = 7.51For a certain chemical reaction, the standard Gibbs free energy of reaction at 30.0 °C is 110. kJ. Calculate the equlilibriunm constant K for this reaction. Round your answer to 2 significant digits.
Answer:
Explanation:
The equation that relates standard Gibbs free energy, ΔG, with equilibrium constant, K, is:
ΔG = -RT ln K
Where R is gas constant, 8.314J/molK, and T is absolute temperatue (30.0°C + 273.15 = 303.15K).
Replacing (110kJ = 110000J):
110000J/mol = -8.314J/molK*303.15K ln K
-43.644 = lnK
1.11x10⁻¹⁹ = K
A sample of 325 mg of neon occupies 2 dm^3 at 20.0 c. use the perfect gas law to determine the pressure of the gas.
Answer:
0.1935atm is the pressure of the gas.
Explanation:
In the problem you have the mass of Neon (You can obtain moles using molar mass), you have volume, and temperature. You can use general ideal gas law to solve pressure:
PV = nRT
P = nRT / V
Where P is pressure in atm, n are moles, R is gas constant (0.082atmL/molK), T is absolute temperature (20.0°C + 273.15 = 293.15K), and V is volume in L = Volume in dm³
Moles gas:
Molar mass Ne = 20.1797g/mol
0.325g * (1mol / 20.1797g) = 0.0161 moles
Replacing:
P = nRT / V
P = 0.0161 moles * 0.082atmL/molK * 293.15K / 2L
P = 0.1935atm is the pressure of the gas
explain how the shape of the root hair cell is adapted to help it do its job
a cooking cylinder can withstand a pressure of 24 ATM at 27 degree Celsius the pressure of the containing gas is a 12 ATM than the minimum temperature above which cylinder will explode is
1)327⁰c
2)273⁰c
3)300k
4)600k
Answer:
Option A. 327 °C
Explanation:
The following data were obtained from the question:
Initial pressure (P1) = 12 atm
Initial temperature (T1) = 27 °C
Final pressure (P2) = 24 atm
Final temperature (T2) =?
Next, we shall convert 27 °C to Kelvin temperature. This can be obtained as follow:
Temperature (K) = Temperature (°C) + 273
Initial temperature (T1) = 27 °C
Initial temperature (T1) = 27 °C + 273
Initial temperature (T1) = 300 K
Next, we shall the temperature at which the cylinder will explode as follow:
Initial pressure (P1) = 12 atm
Initial temperature (T1) = 300 K
Final pressure (P2) = 24 atm
Final temperature (T2) =?
P1/T1 = P2/T2
12/300 = 24/T2
Cross multiply
12 × T2 = 300 × 24
Divide both side by 12
T2 = (300 × 24) /12
T2 = 600 K
Finally, we shall convert 600 K to celsius temperature.
This can be obtained as follow:
Temperature (°C) = Temperature (K) – 273
Temperature (K) = 600 K
Temperature (°C) = 600 – 273
Temperature (°C) = 327 °C
Therefore, the minimum temperature at which the cylinder will explode is
327 °C.
Three different samples were weighed using a different type of balance for each sample. The three were found to have masses of 0.6160959 kg, 3.225 mg, and 5480.7 g. The total mass of the samples should be reported as?
Answer:
6.1 kg
Explanation:
To obtain the total mass of the sample, we must first express each mass of the sample in the same unit of measurement.
Since the SI unit of mass is kilogram (kg), we shall express the total mass of the samples in kilogram (kg).
This is illustrated below:
Mass of the samples are:
M1 = 0.6160959 kg
M2 = 3.225 mg
M3 = 5480.7 g.
Conversion of 3.225 mg to kg
1 mg = 1×10¯⁶ kg
Therefore,
3.225 mg = 3.225 × 1×10¯⁶
3.225 mg = 3.225×10¯⁶ kg
Conversion of 5480.7 g to kg
1000 g = 1 kg
Therefore,
5480.7 g = 5480.7 /1000
5480.7 g = 5.4807 kg
Thus, we can obtain the total mass of the samples as follow:
M1 = 0.6160959 kg
M2 = 3.225×10¯⁶ kg
M3 = 5.4807 kg
Total mass =?
Total mass = M1 + M2 + M3
Total mass = 0.6160959 + 3.225×10¯⁶ + 5.4807
Total mass = 6.096799125 ≈ 6.1 kg
Therefore, the total mass of the samples is approximately 6.1 kg.
HELP MEEEE! ‘’’’’’’’’’
Answers
1) 0.55 meters
2) 3500 millimoles
3) 1600 grams
4) 0.0025 kilograms
5) 40 millimeters
6) 5000 milliliters
7) 43200 seconds in 12 hours
86400 seconds in 24 hours
HOPE THIS HELPS:)
Whoever made this needs to do it their self because this took lots of googling. I see that this was just a practice problem so if you have a test google has a great conversion tool, it gives answers right away.
Explanation: