The standard enthalpy of formation (ΔHf) for nitromethane can be calculated using the enthalpy of combustion. The enthalpy of combustion for nitromethane is -709.2 kJ/mol. By comparing the balanced combustion equation for nitromethane with a general combustion equation, we can determine that the ΔHf for nitromethane is 1418.4 kJ/mol.
Explanation:The standard enthalpy of formation (ΔHf) for nitromethane can be calculated using the enthalpy of combustion and other known values. The enthalpy of combustion for nitromethane is -709.2 kJ/mol. The balanced combustion equation for nitromethane is 2CH3NO2(l) + 3/2O2(g) → 2CO2(g) + 3H2O(g) + N2(g).
By comparing this equation to the general equation for combustion of hydrocarbons (CxHy + zO2 → xCO2 + (y/2)H2O), we can see that the molar ratio between nitromethane and CO2 is 2:2, which means that the ΔHf for nitromethane is twice the enthalpy of combustion, resulting in a value of -2 * (-709.2 kJ/mol) = 1418.4 kJ/mol.
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Dead space is the portion of the respiratory system that: Select one: A.. must be filled with air before gas exchange can take place. B. contains no alveoli and does not participate in gas exchange. C. includes the alveoli and capillaries surrounding the alveoli. D. receives oxygen but is unable to release carbon dioxide.
Answer: Option B
Explanation:
Dead space is the volume of sir in the body which is inhaled but it does not takes part in the gaseous exchange this is because it does not contains alveoli.
Not all the air that is inhaled inside the body is used in the process of respiration.
The dead space in the lungs is the region which helps in conducting airways, the air is not perfused to the alveoli.
Dead space is the portion of the respiratory system that contains no alveoli and does not participate in gas exchange. Therefore, option B is correct.
The respiratory system is a complex network of organs and tissues involved in the process of respiration.
Dead space refers to the portion of the respiratory system where there is no gas exchange occurring. It includes areas such as the trachea, bronchi, and bronchioles, which do not have alveoli. In these regions, the primary function is to conduct air to and from the alveoli, but no actual gas exchange occurs.
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Solution A is 0.44 M and reacts with 0.11 M of solution B. Assume that the value of x is 0, the value of y is 1, and r is 1.07 × 10⁻¹ /s. Find the rate constant for this reaction.
Final answer:
The rate constant for the reaction is 0.973 L/mol/s.
Explanation:
In the given question, we are provided with the initial concentration of solution A and solution B, as well as the values of x, y, and r. To find the rate constant for this reaction, we can use the rate equation:
rate = k[A]^x[B]^y
Substituting the given values:
0.107/s = k(0.44 M)^0(0.11 M)^1
Simplifying the equation:
0.107/s = k(0.11 M)
Dividing both sides by 0.11 M:
k = 0.107/s / 0.11 M = 0.973 L/mol/s
Broad-spectrum pesticides: kill beneficial organisms in addition to the targeted pest. are readily broken down into safe materials such as water and CO2. are ineffective.
Answer:
kill beneficial organisms in addition to the targeted pest
Explanation:
The use of pesticides have emerged as one of the main options used in the control of invertebrate pests in different parts of the world. Organophosphate is the mostly used form of pesticide in places like Australia. There have been reported issues of crops losses from the incidences of pests, despite the increase in the use of pesticides. Broad spectrum pesticides end up kill non-target invertebrate species together with the insects and mites they are out to eliminate
Where would you expect to find many hydrophobic amino acids in the 3-D structure of a folded protein that functions in an aqueous solution?
Answer:
Hydrophobic amino cluster on the inside of the 3-D structure of the folded protein
Explanation:
Hydrophobic interactions, describe the process in which nonpolar, hydrophobic amino acids cluster or aggregate together in the internal part of the protein, to allow the hydrophilic amino acids interact with surrounding water molecules on the outside.
Lead has a density of 11.34 g/ml where as mercury has a density of 13.6 g/ml. If 1 kg of each were placed in buckets of water which one would displace more water?
If you are involved in a vehicle accident, you should not drink any alcohol up to ___ hours after the accident or you could be legally charged with operating a vehicle while under the influence of alcohol.
Answer: 6
Explanation:
Alcohol is a psychoactive drug with a high number of side effects that can seriously affect our body. The amount and circumstances of consumption play an important role in determining the duration of intoxication. For example, consuming alcohol after a large meal is less likely to produce visible signs of intoxication than on an empty stomach.
Alcohol has a two-phase effect on the body, meaning that its effects change over time. Initially, it produces feelings of relaxation and joy, but later consumption can lead to blurred vision and coordination problems. Cell membranes are highly permeable to alcohol, so once alcohol is in the bloodstream, it can spread to almost all body tissues.
Unconsciousness can follow excessive consumption, and extreme levels of consumption can lead to alcohol poisoning and death. Death can also be caused by asphyxiation, if vomit - a frequent result of excessive drinking - blocks the windpipe and the individual is too drunk to respond. An appropriate first-aid response to an unconscious, drunk person is to place him or her in the recovery position.
When alcohol enters the bloodstream (30-90 minutes after ingestion), there is a decrease in the sugars present in the bloodstream, causing a feeling of weakness and physical exhaustion. This is because alcohol accelerates the transformation of glycogen (a substance that stores sugar in the liver) into glucose, which is then eliminated more quickly.
After the ingestion of alcohol, a series of effects or symptoms occur in the short term, depending on the dose ingested (although other individual factors are affected).
Euphoria and excitement phaseIntoxication: The nervous system is affected as the loss of the capacity to coordinate movements is caused, producing imbalance and sometimes falls. If abused, locomotor ataxia can occur, which is a paralysis characteristic of alcoholics. Hypnotic or confused phase: Irritability, agitation, drowsiness, headache, ysarthria, ataxia, dysmetry, nausea and vomiting. Anaesthetic phase or stupor and coma, inconsistent language. Bulbar or death phase: Cardiovascular shock, inhibition of the respiratory center, cardio-respiratory arrest and death.Alcohol is broken down mainly in the liver, which can metabolize about 1 drink per hour for men. Factors such as age, weight, gender, and the amount of food eaten can affect how quickly the body can process alcohol. The amount of time alcohol can be detected in blood is up to 6 hours. Then it is not recommended to drink alcohol until after 6 hours if you have been involved in an accident, since alcohol can be detected in the blood in that time range. Because of the effects alcohol has on the body and how it can affect driving, if alcohol is detected you can be legally charged with driving under its influence.
A block weighing 8.5 N requires a force of 2 Nto push it along at constant velocity.What is the coefficient of friction for thesurface?
Answer:
The coefficient of friction of the surface μ = 0.235
Explanation:
Values of the given variables:
Weight of block = 8.5 N
Pushing force F = 2 N
velocity = constant
Solution:
Newton's Second Law of motion states that acceleration of an object depends on the mass of the object and the force applied
F = m a
Since v =constant, a = 0. Thus
Net force Fnet = 0.
Now F_net is the sum of the pushing force and the frictional force along the horizontal, which opposes the motion:
Fnet = Fpushing - Ffrictional_force
Given that Fnet = 0, Fpushing = Ffrictional_force. and Ffrictional_force = 2 N
Equation of friction is given by
Ffrictional_force = μ*W
2 = μ*8.5
μ = 2/8.5 = 0.235
The coefficient of friction for the surface is approximately 0.235.
Explanation:The coefficient of friction can be determined using the equation:
frictional force = coefficient of friction × normal forceGiven that the weight of the block is 8.5 N, and the force required to push it at constant velocity is 2 N, we can determine the normal force as follows:
normal force = weight of the blocknormal force = 8.5 NSubstituting the values into the equation:
2 N = coefficient of friction × 8.5 NSolving for the coefficient of friction:
coefficient of friction = 2 N / 8.5 Ncoefficient of friction ≈ 0.235Therefore, The coefficient of friction for the surface is approximately 0.235.
Check all that apply.
a. Cathode rays have mass.
b. There are subatomic size particles in an atom.
c. In the atom, the particles of the cathode rays are embedded in a diffuse cloud of positive charge.
d. Matter contains negative charge and by inference positive charge.
e. Particles of the cathode rays are fundamental to all matter.
Answer:
a.Cathode rays have mass.
b.They are subatomic size particles in an atom.
d. Matter contains negative charge and by inference positive charge.
e. Particles of the cathode rays are fundamental to all matter.
Explanation:
The statements above reflect the Thompson model of the atom. Electrons were first known as cathode rays. The Thompson's model viewed the atom as a sphere of negative charges into which positive charges were embedded. This is the plum pudding model of the atom.
A student obtains a mixture of the chlorides of two unknown metals, X and Z. The percent by mass of X and the percent by mass of Z in the mixture is known. Which of the following additional information is most helpful in calculating the mole percent of XCl(s) and of ZCl(s) in the mixture?
Answer:
the Molar masses of Z and X
Explanation:
The percent by mass of X states how many grams of X are in 100 grams of the mixture. Then, we know how many grams of X, Z (we also know its percent) and of Cl ( = 100 - X % - Z %). Taking 100 g of the mixture as a base, we have:
x grams of X
z grams of Z
y grams of Cl
With the molar masses of Z and X (and of Cl) we can transform all masses into moles and then compute the mole percent of XCl(s) and of ZCl(s) in the mixture
From the given information:
The percent by mass of X = KnownThe percent by mass of Z = KnownThe percentage mass is given as the mass of the element which is divided by mass of compound multiplied by 100.
it is estimated using the formular:
[tex]\mathbf{percentage \ mass = \dfrac{\text{mass of element in 1 mole of compound}} { \text{mass of 1 mole of compound}} \times 100}[/tex]
From there;
The mole percentage is determined, which is the ratio of moles in a substance (element or compound) divided by the total amount of the mixture.
Using the formula:
Mole percentage = mole fraction × 100
Since the mole fraction is not given, it can be estimated as well by using the formula:
[tex]\mathbf{Mole\ fraction = \dfrac{\text{No of moles of a component} }{\text{total number of moles of the compound}}}[/tex]
Eventually; To determine the unknown number of moles, we will need the value of their respective molar masses(i.e. for X and Z) by using the formula:
[tex]\mathbf{Number \ of \ moles = \dfrac{Mass}{Molar \ Mass}}[/tex]
In conclusion, the additional information required in calculating the mole percent of XCl(s) and ZCl(s) in the mixture is the molar mass of X and Z.
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A 44.0mg sample of carbon reacts with sulfur to form 122 mg of the compound.
What is the empirical formula of the carbon sulfide? Express answer as a chemical formula.
Answer:
Empirical formula = C₃S₂
Explanation:
Given data:
Mass of carbon = 44.0 mg (44/1000 = 0.044 g)
Mass of sulfur = 122 mg - 44.0 mg = 78 mg = 78/1000 = 0.078 g)
Empirical formula = ?
Solution:
First of all we will calculate the number of moles.
Number of moles of carbon = mass / molar mass
Number of moles of carbon = 0.044 g/ 12.01 g/mol
Number of moles of carbon = 0.0037 mol
Number of moles of sulfur:
Number of moles = mass / molar mass
Number of moles = 0.078 g/ 32,066 g/mol
Number of moles = 0.0024 mol
Now we will compare the moles:
C : S
0.0037/0.0024 : 0.0024/0.0024
1.5 : 1
C : S = 2(1.5 : 1)
C : S = 3 : 2
Empirical formula = C₃S₂
A solution surrounding a cell is hypertonic solution if: a. It contains fewer nonpenetrating solute particles than the interior of the cell b. It contains more nonpenetrating solute particles than the interior of the cell c. It contains the same amount of nonpenetrating solute particles as the interior of the cell
Answer:
The answer is B. It contains more non-penetrating solute particles than the interior of the cell.
Explanation:
This means that it has a greater concentration or number of solute particles outside a membrane than there are inside it.
A typical example is Saline solution.
In a hypertonic solution, the extracellular fluid has a higher concentration of solutes than the cell's cytoplasm. Water will leave the cell, causing it to shrink.
Explanation:A hypertonic solution is any external solution that has a high solute concentration and low water concentration compared to body fluids. In a hypertonic solution, the net movement of water will be out of the body and into the solution.
This means that the solution contains more nonpenetrating solute particles than the interior of the cell. As a result, water will leave the cell, causing it to shrink.
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(a) How many moles of CO2 contain 2.42 ✕ 1024 molecules?
WebAssign will check your answer for the correct number of significant figures. [blank] mol CO2
(b) What number of moles is equivalent to 6.23 ✕ 1021 atoms of Hg?
WebAssign will check your answer for the correct number of significant figures. [blank] mol Hg
Please fill in the blanks
When calculating the number of moles of CO₂ and Hg, we have:
a) There are 4.02 moles of CO₂ in 2.42x10²⁴ molecules.
b) There are 0.010 moles of Hg in 6.23x10²¹ atoms.
a) The number of moles of CO₂ that are in 2.42x10²⁴ molecules can be calculated with Avogadro's number (N = 6.022x10²³)
[tex] n = \frac{1 mol}{6.022 \cdot 10^{23} \:molecules}*2.42 \cdot 10^{24} \:molecules = 4.02 moles [/tex]
Hence, the number of moles of CO₂ is 4.02.
b) To find the number of moles of Hg equivalent to 6.23x10²¹ atoms, we need to use Avogadro's number:
[tex] n = \frac{1 mol}{6.022 \cdot 10^{23} \: atoms}*6.23 \cdot 10^{21} \: atoms = 0.010 moles [/tex]
Therefore, the number of moles of Hg is 0.010.
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Titanium (III) chloride, a substance used in catalysts for preparing polyethylene, is made by high-temperature reaction of TiCl4 vapor with H2 :
2TiCl4(g) + H2(g) --> 2TiCl3(s) + 2HCl(g)
a) how many grams of TiCl4 are needed for complete reaction with 155L if H2 at 430 degrees C and 780mmHg pressure?
b) How any liters of HCl gas at STP will result from the reaction described in part (a)?
Answer: a. 1046.98g b. 123.64 L
Explanation:
.a. To determine the mass of TiCl4 needed to complete the reaction with 155 liters of H2 at 430 degree Celsius and 780 mmHg pressure.
First, use the ideal gas equation to determine the number of moles of H2.
PV = nRT
R= 0.082 Latm/molK
Convert Pressure to atmosphere and temperature to kelvin so the units of calculation can be uniform;
1 atm is equals to 760 mmHg so 780mmHg will be (780/760) atm = 1.0263 atm
430 degree Celsius = (430 +273.15) K
= 703.15 K
Therefore, n = PV/RT
= (1.0263*155)/ (0.082*703.15)
= 2.76 of H2 will be needed to complete the reaction
From the chemistry of the reaction, it can be seen that 2 moles of TiCl4 is needed to react with 1 mole of H2.
So for 2.76 moles of H2 , (2*2.76 moles) of TiCl4 will be needed which is equals to 5.52 moles of TiCl4.
The mass of TiCl4 can be calculated using the formular;
Mass = molar mass * number of moles
The molar mass of TiCl4 cab be calculated using the molar mass of each of its element (Ti =47.87 g/mol, Cl= 35.45 g/mol).
The molar mass of TiCl4 = 47.87 + (4*35.35) = 189.67 g/mol
Therefore,
The mass of TiCl4 = 189.67 g/mol * 5.52 mols
= 1046.98 g of TiCl4.
b. The amount of liters of HCl gas to be produced at STP. STP means standard temperature and pressure which is 273.15 K and 1 atm
From the chemistry of the reaction, it can be seen that with 1 mole of H2 is needed to produce 2 moles of HCl.
So for 2.76 moles of H2, (2*2.76 moles) of HCl will be produced which is equals to 5.52 moles of HCl. Therefore, the volume of HCl produced at 430 degree Celsius and 780 mmHg pressure will be;
V = nRT/P
= 5.52* 0.082 *703.15 / 1.0263
= 310.118 L
The combined gas law states that PV/T = constant. Therefore
P1V1/T1 = P2V2/T2
Now using the combined gas law;
P1 = 1.0263 atm, V1 = 310.118 L, T1 = 703.15 K
P2 = 1 atm, V2 =?, T2 = 273.15 k
So,
V2 = (1.0263*310.118*273.15)/ (1*703.15)
= 123.64 L
To find the grams of TiCl4 needed, use the ideal gas law equation and the balanced chemical equation. To find the liters of HCl gas at STP, use the ideal gas law equation and the balanced chemical equation.
Explanation:In order to determine the grams of TiCl4 needed, we need to use the ideal gas law equation: PV = nRT. First, we need to convert the given volume of H2 to moles by using the ideal gas law. Then, we can use the balanced chemical equation to find the ratio of moles of H2 to moles of TiCl4. Finally, we can convert moles of TiCl4 to grams using the molar mass of TiCl4.
To determine the liters of HCl gas at STP, we can use the ideal gas law equation again. We can find the moles of HCl gas produced by using the balanced chemical equation, and then convert the moles to liters at STP using the molar volume of a gas at STP.
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1. Do you think evolution is still taking place in the Galapagos finches? Why or why not?
2. Discuss whether or not human activities lead to speciation. Explain your reasoning.
The answers are as follows:
1) Evolution is still taking place in the Galapagos finches
Why?
Evolution basically consists on random mutations that affect the population of a species, that are conserved when those mutations help the affected individuals to better adapt to their environment, in a process known as natural selection.
Random mutations are still affecting the finch population in the Galapagos Islands, and when one of those mutations provides an advantage, the species will continue to evolve. However, these changes occur over long periods of time, and its unlikely that we will see the evolved species in our lifetime.
2) Human activities can lead to speciation
Speciation is the process in which new species are created by natural or artificial selection.
Why?
Human activities can speed up this process by creating external pressure in the form of artificial selection. There are many examples of this in our history, but common cases are the separation of the Dog (Canis familiaris) from the Wolf (Canis lupus). Wolves with desirable traits (non-aggressive, cooperative, small size) were artificially selected by humans and in time, a new species was created. Other examples can be the different species of cattle and sheep.
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____ are weak bonds that are not strong enough to hold atoms together to form molecules but are strong enough to form bridges between molecules. a. Hydrogen bonds
b. Covalent bonds
c. Ionic bonds
d. Anionic bonds
e. Polar covalent bonds
Answer:Hydrogen bonds
Explanation:
Hydrogen bonds occur between molecules when hydrogen is covalently bonded to a highly electronegative element in each molecule of the compound E.g water. Hydrogen bonds are intermolecular bond forces. They hold molecules of a substance together in a particular state of matter. They do not link atoms together but they form bridges between molecules. Hydrogen bonds exist in liquid, solid and gaseous states of matter.
Hydrogen bonds are weak bonds that form bridges between molecules. They occur when a hydrogen atom is attracted to an atom with a partial negative charge.
Explanation:Hydrogen bonds are weak bonds that are not strong enough to hold atoms together to form molecules but are strong enough to form bridges between molecules. These bonds occur when a hydrogen atom with a partial positive charge is attracted to an atom with a partial negative charge.
An example of hydrogen bonding is the bond between water molecules. The partial positive charge of the hydrogen atom in one water molecule is attracted to the partial negative charge of the oxygen atom in a neighboring water molecule, resulting in hydrogen bonding.
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A student obtained 1.69 g of pure caffeine following recrystallization from a crude sample, which originally weighed 2.51 g. What is the percent recovery of pure caffeine from crude?
Answer:
The recovery of pure caffeine is 67.3% of the original, crude sample.
Explanation:
Step 1: Data given
Mass of pure caffeine = 1.69 grams
Original mass of sample = 2.51 grams
Step 2: What is the percent recovery of pure caffeine from crude?
Percentage = (mass of recovery / original mass) *100%
Percentage = (1.69 grams/2.51 grams) *100%
Percentage = 67.3 %
The recovery of pure caffeine is 67.3% of the original, crude sample.
"A sphere of radius 0.50 m, temperature 27oC, and emissivity 0.85 is located in an environment of temperature 77oC. What is the net flow of energy transferred to the environment in 1 second?"
Explanation:
It is known that formula for area of a sphere is as follows.
A = [tex]4 \pi r^{2}[/tex]
= [tex]4 \times 3.14 \times (0.50 m)^{2}[/tex]
= 3.14 [tex]m^{2}[/tex]
[tex]T_{a}[/tex] = (27 + 273.15) K = 300.15 K
T = (77 + 273.15) K = 350.15 K
Formula to calculate the net charge is as follows.
Q = [tex]esA(T^{4} - T^{4}_{a})[/tex]
where, e = emissivity = 0.85
s = stefan-boltzmann constant = [tex]5.6703 \times 10^{-8} Wm^{-2} K^{-4}[/tex]
A = surface area
Hence, putting the given values into the above formula as follows.
Q = [tex]esA(T^{4} - T^{4}_{a})[/tex]
= [tex]0.85 \times 5.6703 \times 10^{-8} Wm^{-2} K^{-4} \times 3.14 \times ((350.15)^{4} - (300.15)^{4})[/tex]
= 1046.63 W
Therefore, we can conclude that the net flow of energy transferred to the environment in 1 second is 1046.63 W.
A sample of argon gas has a volume of 500 mL at a pressure of 1.5 atm. If the pressure is increased to 4.0 atm, the new volume is given by
Answer:
187.5 mL
Explanation:
From the question we are given;
Initial volume of the gas, V₁ = 500 mLInitial pressure of the gas, P₁ = 1.5 atmNew pressure of the gas, P₂ = 4.0 atmWe are required to determine the new volume of the gas;
We are going to use Boyle's law of gases.
According to Boyle's law, the volume of a fixed mass of a gas and pressure are inversely proportional at a constant absolute temperature.That is;[tex]P\alpha\frac{1}{V}[/tex]
[tex]P=\frac{k}{V}[/tex]
At different pressures and volume with constant temperature, then
[tex]P_{1}V_{1}=P_{2}V_{2}[/tex]
Rearranging the formula;
[tex]V_{2}=\frac{P_{1}V_{1}}{P_{2}}[/tex]
Thus;
[tex]V_{2}=\frac{(500mL)(1.5 atm)}{4.0 atm}[/tex]
[tex]=187.5 mL[/tex]
Thus, the new volume of the gas is 187.5 mL
Answer:
1.5x500
————-
4.0
Explanation:
The combustion of palmitic acid in a bomb calorimeter yields energy in the form of heat released upon oxidation. From a thermodynamic perspective and with respect to the calorimeter experiment, what would you expect the combustion of the same amount of palmitic acid in our body to yield?a. less energyb. more energyc. the same amount of energyd. The calorimeter experiment is irrelevant to the combustion of palmitic acid in the human body.
Answer:
"The same amount of energy" is the combustion of the same amount of palmitic acid in our body to yield.
Explanation:
A bomb calorimeter is an apparatus used to measure the amount of heat out or fascinated by a chemical reaction. This apparatus is airtight and has thermal insulation, which means that the organization doesn't alteration heat with the environments. So, by the variance of the temperature measured on the system (ΔT), the mass of a solution (m) and the specific heat of water (c) it's likely to compute the heat in a reaction that happens in aqueous solution, by the equation below:
Q = [tex]m \times c\times \delta T[/tex]
The heat, or the energy, of the response doesn't depend on where the response is happening, so the sum of energy measured on the bomb calorimeter will be the same in our body.
If an atom of thorium-234 were to undergo beta emission twice, which atom would result?
Rn-226
U-234
Th-230
U-238
Answer:
The answer to your question is U-234
Explanation:
Data
Thorium-234
beta emission twice
Definition
Beta emission is when a beta particle (electron) is emitted from an atomic nucleus.
First beta emission
²³⁴₉₀Th ⇒ ²³⁴₉₁Pa + e⁻
Second beta emission
²³⁴₉₁ Pa ⇒ ²³⁴₉₂U + e⁻
The atom will be Uranium-324
Answer: U-234
Explanation: no matter how much of beta decay, the mass number of the resulting element is unchanged
Mendeleev organized the elements
a. alphabetically by name.
b. by the number of electrons.
c. by increasing the atomic number and similar properties.
d. by increasing atomic weight and similar properties.
Answer:
D
Explanation:
Mendeleev was a Russian scientist. His works provided the framework for the present day periodic table. What Mendeleev did was to arrange the elements in order of their atomic weights.
He however had some gaps in his periodic table. He impressively predicted the elements that would fill in these blank spaces even though they were yet to be discovered as at then.
How many hydrogen atoms are connected to the indicated carbon atom?
Answer:
Your question is incomplete, but it could deal with organic structures just like the ones I attached in this answer. So I hope it helps you.
Q1. A) One hydogen atom
Q2. E) None
Q3. A) One Hydrogen atom
Explanation:
Each carbon can make 4 covalent bonds with Hydrogene because of its 4 valencies. If a carbon has only three covalent bonds, the C atom will be charged; in the 3 questions that I´m aswering here, the carbons are charged and they are carbocations (there is no lone pair of electrons and the charge is positive). We can also find carbanions (there is one lone pair of electrons and the charge is negative).
In the molecules on the attachement file, you can notice that the first one has already 2 bonds with adjacent carbons, the next one has 3 bonds and the last one has 2; in every structure, the indicated carbon is a carbocation (no lone pairs of electons). A cabocation can make 3 covalent bonds, so, for the first and the last molecules, there is one hyrogen atom connected to it, for the second there is none.
The removal of silver tarnish from silverware using aluminum foil and a solution of electrolyte is an example of
A) oxidation of aluminum metal.
B) reduction of silver ions.
C) an electrochemical cell.
D) all of the above
Answer:
The answer is C. An electrochemical cell.
Explanation:
The aluminum ion react with the sulfide to form aluminum sulfide.
If a proton and an electron are released when they are 5.50×10−10 mm apart (typical atomic distances), find the initial acceleration of each of them.
Answer: The initial acceleration of the proton = (4.56 × 10^23) m/s2
The initial acceleration of the electron = (8.36 × 10^26) m/s2
Explanation: The force of attraction between the proton and electron can be computed using the statements of Coulomb's law which state that the force of attraction between two charged particles is directly proportional to the product of the two charges and inversely proportional to the square of their distances apart.
F = (Kq1q2)/(r^2) where K = (9 × (10^9) Nm(C^-2))
But q1 is the charge on a proton = (1.6 × (10^-19)) C
q2 is charge on an electron = -(1.6 × (10^-19)) C
r = (5.50 × (10^-10))mm = (5.50 × (10^-13))m
Computing all that, F = 0.0007616529 N = (7.62 × 10^-4) N
But the force of attraction is converted to that required for motion when they're released.
F = ma.
For proton, m = (1.67 × 10^-27) kg
a = F/m = 0.000762/(1.67 × 10^-27) = (4.56 × 10^23) m/s2
For electron, m = (9.11 × 10^-31) kg
a = F/m = 0.000762/(9.11 × 10^-31) = (8.36 × 10^26) m/s2
QED!
Final answer:
The initial acceleration of a proton and an electron, when released 5.50×10−10 mm apart, can be found using Coulomb's law and Newton's second law. The electrostatic force is first calculated using the charge of the particles and the separation distance, then divided by their respective masses to find their accelerations.
Explanation:
To calculate the initial acceleration of a proton and an electron when they are 5.50×10−10 mm apart, we use Coulomb's law which states that the electrostatic force (F) between two charges is proportional to the product of the charges and inversely proportional to the square of the distance between them. The formula is F = k × (q1 × q2) / r2, where k is the electrostatic constant (8.99×109 N×m2/C2), q1 and q2 are the charges of the proton and electron, and r is the separation distance. The acceleration (a) of each particle can then be found using Newton's second law (F = m × a), by dividing the electrostatic force by the mass (m) of the proton or electron respectively.
For a proton, the charge is +1.602×10−19 C and mass is 1.67×10−27 kg. For an electron, the charge is −1.602×10−19 C and mass is 9.11×10−31 kg. The initial acceleration for each particle can be calculated by using their respective masses and the electrostatic force derived from Coulomb's law.
Manganese nodules are considered a valuable resource from the ocean floor because they are abundant and contain not only manganese but also?
Answer: iron (oxides of iron)
Explanation: manganese nodules usually contain layers of iron and manganese oxides in a concentric arrangement and are called polymetallic nodules.
Which of the following pairs of substances best illustrates the law of multiple proportions?
Answer:
Answer:
Which of the following pairs of substances best illustrates the law of multiple proportions?
A. H2 and O2
B. NO and NO2
C. P2O5 and PH3
D. CaCl2 and CaBr2
B. NO and NO2
best shows the law of multiple proportions.
Explanation:
Which of the following pairs of substances best illustrates the law of multiple proportions?
A. H2 and O2
B. NO and NO2
C. P2O5 and PH3
D. CaCl2 and CaBr2
B. NO and NO2
best shows the law of multiple proportions.
law of simple multiple proportions. Law of multiple proportions, states that when two elements react with oneaother to form more than one compound, the weights of one element that combine with the fixed weight of the other element are in small whole number ratios.
Here Nitrogen, N which is fixed combines with Oxygen in two compounds in ratios 1 to 1 and 1 to 2
If an aqueous solution of lead(II) nitrate (Pb(NO3)2) is mixed with an aqueous solution of potassium chloride (KCl) the precipitate is:
Answer: lead(II) chloride PbCl2
Explanation:
Pb(NO3)2 + 2KCl —> PbCl2 + 2KNO3
Taking into account the definition of net ionic equation, a precipitate of PbCl₂ is formed when an aqueous solution of lead(II) nitrate (Pb(NO₃)₂) is mixed with an aqueous solution of potassium chloride (KCl) .
The net ionic equation is a chemical equation for a reaction that lists only the species that participate in the reaction.
In other words, an ionic equation is a chemical equation where electrolytes in aqueous solution are written as dissociated ions.
In this case, the balanced equation will be:
Pb(NO₃)₂ (aq) + 2 HCl (aq) → PbCl₂ (s) + 2 HNO₃ (aq)
where (aq) means aqueous and (s) solid.
Taking into account that:
All Cl⁻, Br⁻ and I⁻ salts are soluble. All salts of NO₃⁻, C₂H₃O₂⁻, ClO₃⁻ and ClO₄⁻ are soluble.All Ag⁺, Pb²⁺ and Hg₂²⁺ salts are insoluble.The total ionic equation in separated aqueous solution will be:
Pb²⁺(aq) + 2 NO₃⁻(aq) + 2 H⁺ (aq) + 2 Cl⁻ (aq) → PbCl₂ (s) + 2 H⁺ (aq) + 2 NO₃⁻ (aq)
A spectator ion is an ion that appears both as a reactant and as a product in an ionic equation.
Spectator ions can be either cations (positively charged ions) or anions (negatively charged ions).
When writing a net ionic equation, spectator ions found in the original equation are ignored. Thus, the total ionic reaction is different from the net chemical reaction.
In this case, H⁺ and NO₃⁻ are the spectator ions because they appear unchanged in both the product and the reagent. So these ions cancel out by writing the net ionic equation and you get:
Pb²⁺(aq) + 2 Cl⁻ (aq) → PbCl₂ (s)
Since PbCl₂ is an insoluble salt, it will precipitate.
Finally, a precipitate of PbCl₂ is formed when an aqueous solution of lead(II) nitrate (Pb(NO₃)₂) is mixed with an aqueous solution of potassium chloride (KCl) .
Learn more:
brainly.com/question/18896765?referrer=searchResults brainly.com/question/10553963?referrer=searchResults brainly.com/question/7018960 brainly.com/question/24099019?referrer=searchResults brainly.com/question/10538922?referrer=searchResultsA white substance melts with some decomposition at 730oC. As a solid it does not conduct electricity, but it dissolves in water to form a conducting solution. With explanation, which type of solid might the substance be?
Answer:
Ionic solid
Explanation:
Ionic solids -
These are the type of solids , which is composed of ions , which are bond by very strong electrostatic force of attraction , are referred to as ionic solids.
And due to very strong force of attraction between the ions , they generally have very high melting point.
When the solid is dissolved in water , the ions gets separate out , and these free ions are capable to conduct electricity , and hence they are very good conductor in molten form , and are insulator in solid form.
Hence , from the given information of the question ,
The correct term is ionic solids.
Which response includes all the following that are properties of most metals, and no other properties?
Z1) They tend to form cations.
Z2) They have high first ionization energies.
Z3) They have outer electronic shells that are more than half-filled.
Z4) They tend to form ionic compounds when they combine with the elements Group VIIA.
1. Z3 and Z4 only
2. Z2, Z3, and Z4 only
3. Z1, Z2, and Z3 only
4. Z1 and Z4 only
5. Z1 and Z3 only
Answer:Z1 and Z4 only
Explanation:
One general property of all metals is that they form positive ions (cations) by electron loss. Secondly, elements of group VIIA have high electron affinities hence they easily accept electrons to form negative ions. The bonding between metals and elements in this group is almost always ionic in nature.
If you start with 10.0 grams of lithium hydroxide and an excess of hydrogen bromide, how many grams of lithium bromide will be produced?
Answer:
grams of lithium bromide produced = 36.2642309286 ≈ 36.30 g
Explanation:
The equation of the reaction is as follows ;
Lithium hydroxide + hydrogen bromide → Lithium Bromide + water
LiOH + HBr → LiBr + H2O
The equation is already balanced
Molecular mass of LiOH = 6.941 + 15.999 + 1.00784
Molecular mass of LiOH = 23.94784 g
Molecular mass of LiBr = 6.941 + 79.904 = 86.845 g
From the equation
LiOH + HBr → LiBr + H2O
23.94784 g of lithium hydroxide produces 86.845 g of lithium bromide
10 g of lithium hydroxide will produce ?
cross multiply
grams of lithium bromide produced = 10 × 86.845/23.94784
grams of lithium bromide produced = 868.45/23.94784
grams of lithium bromide produced = 36.2642309286 ≈ 36.30 g