1) Resting potential is generated mainly by the outward movement of K+ ions from inside the cell. (True)
2) The voltage changes shown in the figure are measured just across the plasma membrane (True)
3) The changes in voltage seen at #2 and #4 in the figure are caused by similar movements, in the same direction, of the same types of ions across the membranes.(false)
4) The trace in the figure is following the voltage change as it moves down the axon. (false)
5) The voltage change shown in the figure is an all-or-nothing response. (True)
Definition of Electric VoltageElectric Voltage is the amount of energy needed to move a unit of electric charge from one place to another. The electric voltage expressed in volts is also often referred to as the electric potential difference because basically the electric voltage is a measure of the potential difference between two points in an electric circuit.
An object is said to have a higher electric potential than other objects because the object has a greater amount of positive charge than the number of positive charges on other objects. While what is meant by electric potential itself is the amount of charge contained in an object.
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The ions formed when mgi₂ dissociates in water are?
When magnesium iodide (MgI₂) dissociates in water, it produces two Mg2+ cations and two I- anions, according to the following equation:
MgI₂(aq) → Mg2+(aq) + 2I-(aq).Chemical reactions are processes in which atoms or molecules of one or more substances are rearranged to form new substances with different properties. Chemical reactions involve the breaking and forming of chemical bonds, which releases or absorbs energy.
For example, a reaction between hydrogen and oxygen can form water, which has different properties than the two gases. During a chemical reaction, the starting materials, or reactants, are transformed into new substances, or products. Chemical equations can be used to represent chemical reactions, which allow us to calculate the amount of reactants and products that are involved.
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TRUE or FALSE. Believing that, with training, you will be able to run two miles without stopping by the end of the semester demonstrates self-efficacy.
The statement "Believing that, with training, you will be able to run two miles without stopping by the end of the semester demonstrates self-efficacy." is True.
Self-efficacy is an individual's belief in their ability to successfully perform a specific task or complete a particular goal. Believing that, with training, you will be able to run two miles without stopping by the end of the semester is a demonstration of self-efficacy. This belief in one's abilities can have a significant impact on motivation, effort, and performance, as individuals who have high self-efficacy are more likely to set challenging goals and persist in the face of obstacles and setbacks.
Self-efficacy can be developed and strengthened through various experiences, including mastery experiences (successes), vicarious experiences (observing others), emotional and physiological states, and social persuasion. An individual's self-efficacy can also be affected by situational and dispositional factors, such as their confidence, past experiences, and the difficulty of the task at hand.
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an amino acid that does not derive its carbon skeleton at least in part from oxaloacetate is
Proline is an amino acid that does not, at least partially, get its carbon skeleton from oxaloacetate. Because proline is a nonessential amino acid, the body may make it from other molecules.
Amino and carboxylic acid functional groups can both be found in organic compounds known as amino acids. Of the many different amino acids found in nature, alpha-amino acids, which are the building blocks of proteins, are by far the most important. There are just 22 alpha amino acids in the genetic code. The primary structural functional groups of alpha, beta, gamma, or delta-amino acids can be categorised; further classifications relate to polarity, ionisation, and the type of side chain group (aliphatic, acyclic, aromatic, containing hydroxyl or sulfur, etc.). After water, proteins made of amino acid residues make up the second-largest portion of human muscles and others tissue.
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what is the mass of 7.11x10^24 particles of potassium oxide?
hydrogen has the same number of valence electrons as which family
All of the elements in Group I (alkali metals and hydrogen) have one electron in the outer shell.
All of the elements in Group 1 only have one valence electron. Examples include lithium (Li), sodium, and hydrogen (H) (Na). Group 18 elements all have eight valence electrons (except for helium, which has a total of just two electrons). Neon (Ne), argon (Ar), and krypton are some examples (Kr). The periodic table's hydrogen is a particularly unique element that does not fall under any family. Despite being a member of Group I, hydrogen is not an alkali metal. The group IV elements and carbon share the most similarities with hydrogen in terms of thermodynamic parameters (ionization energy, electron affinity).
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f the mass percent of sulfur in al2(so4)3 is 28.1%, what is the mass of sulfur atoms in grams in 14.8 grams of al2(so4)3?
The mass of sulfur atoms in grams in 14.8 grams of al2(so4)3 is equal to 3.9g
We are informed that this chemical contains 28.1% Sulphur by mass.
This implies that any sample of this substance Additionally, this molecule is Al2 SO4 3. Therefore, sulphur will account for 0.1% of the mass in any sample size of this 28. Therefore, 28.1% of that, whether we have a one g sample or a 1000 g sample, will be attributed to the sulphur. We therefore have a 14 g sample in this inquiry. In order to locate the sulphur mass. Okay, we must multiply the percentage of 28.1 by mass by the sample size, which is 14 g. The quantity of Sulphur in this sample is therefore going to be 3.9 g And I rounded that to two significant digits since 14 only had two significant digits.
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If the pressure of each gas is increased at constant temperature until condensation occurs, which gas will condense at the lowest pressure? responses.
Butane is the gas that will condense at the lowest pressure.
Condensation is the process through which matter transitions from its initial gaseous state into its final liquid state. For instance, condensation happens when water vapour in the air, which is in its gaseous state, comes into touch with a colder surface and turns into liquid water.
The process of condensation, which is the reverse of evaporation, converts airborne water vapor to liquid water. Because it causes clouds to develop, condensation is essential to the water cycle.
When warm air meets cold surfaces or when your home is too humid, condensation happens. This moisture-rich heated air immediately cools down and releases the water, which condenses into liquid droplets on the chilly surface when it comes into contact with it.
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in how many years will the substance contain exactly 202020 grams(\text{g})(g)(, start text, g, end text, )of carbon-141414? give an exact answer expressed as a natural logarithm. years
The substance contain exactly 20 grams(g) of Carbon-14 in 1859 years.
The following equation can be used to determine an isotope's general rate of decay:
A(t) = A₀e^λt
where where A0 is the isotope's initial amount at time t = 0
A(t) is its amount at time t,
and λ is the isotope's decay constant
We have the following equation for the carbon-14 isotope:
A(t) = 25e^0.00012t
which mean
A₀ = 25 g
λ = 0.00012y⁻¹
The time (t) at which there is no more substance is what we're trying to determine.
A(t) = 20 g
Rearranging the equation for t, we thus discover:
t= - ln (A(t)/25) = 1859 years
0.00012
Your question is incomplete but most probably your full question was
A scientist measures the initial amount of Carbon-14 in a substance to be 25 grams. The relationship between A, the amount of Carbon-14 remaining in that substance, in grams, and t, the elapsed time, in years, since the initial measurement is modeled by the following equation.
A= 25e -0.00012t
In how many years will the substance contain exactly 20 grams(g) of Carbon-14?
Give an exact answer expressed as a natural logarithm. years
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a 275.0 μl water sample was analyzed for cadmium. calculate this volume in cubic centimeters (cm3).
The volume in cubic centimetres is 0.275 cubic cm.
We know that
1 millilitre = 1 cubic centimetre
1 litre = 1 cubic metre
275.0 μl water sample = 275 microlitres
275 microlitres = 0.275 mililitre
= 0.275 cubic cm
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Phosphorus trichloride gas and chlorine gas react to form phosphorus pentachloride gas. Pcl3(g) + cl2(g) equilibrium reaction arrow pcl5(g) a gas vessel is charged with a mixture of pcl3(g) and cl2(g), which is allowed to equilibriate at 450 k. At equilibrium the partial pressures of the three gases are ppcl3 = 0. 124 atm, pcl2 = 0. 157 atm, and ppcl5 = 1. 30 atm
When 100 ml of 0.10 m HCN and 0.10 m NaOH are titrated, the pH at the equivalence point is 11.04.
Titration is a common laboratory method for quantitative chemical analysis to determine the concentration of an identified analyte. The reagent sometimes referred to as the titrant or titrator, is prepared as a standard solution with a specified concentration and volume. Titration is widely used in the food industry as an analytical technique. It enables food manufacturers to gauge the amount of a reactant present in a sample. For example, it can be used to determine a food's salt, sugar, or vitamin C or E concentration, which changes the product's hue. At the equivalent point, 200 mL of the solution may hold 10 mmol of cyanide ions.
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the lattice energy of naoh is -900 kj/mol. when 2.990 g of naoh is dissolved in water, 3.33 kj of heat is released. calculate the enthalpy of hydration of naoh.
The lattice energy of NaOH is -900 kj/mol. when 2.990 g of naoh is dissolved in water, 3.33 kj of heat is released. The enthalpy of hydration of naoh is 70.6 kJ/mol.
The enthalpy of hydration is the amount of heat released or absorbed when a substance dissolves in water.
To calculate it, we need to subtract the heat of solution due to the breaking of the solid lattice of the solute from the total heat released during the solution process.
First, we need to convert the mass of NaOH to moles:
2.990 g / (40.0 g/mol) = 0.07475 moles
Next, we can calculate the heat of solution due to the breaking of the solid lattice:
0.07475 moles * (-900 kJ/mol) = -67.3 kJ
Finally, we can calculate the enthalpy of hydration:
ΔHhydration = ΔHsolution - ΔHlattice
ΔHhydration = 3.33 kJ - (-67.3 kJ) = 70.6 kJ/mol
So, the enthalpy of hydration of NaOH is 70.6 kJ/mol.
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Bed bugs might sound like an old-fashioned problem, but now they are back with a vengeance. Fifty years ago, the blood-sucking pests were nearly eradicated in the united states thanks in part to the use of pesticides like ddt. Today, they are creeping over sheets and tormenting sleepers across the country. New york was recently declared america's most bed-bug-infested city in america. In the past, we countered the bed bugs by using pesticides called pyrethrins and pyrethroids. These compounds work by attacking the nervous system. Insects have channels in the membranes of their nerve cells that can be opened to allow sodium into the cells, triggering a nerve impulse. Pyrethrins and pyrethroids alter the nervous system by binding to the sodium channels, locking them in the open position. This allows sodium to pour into the cell continuously, causing the nerve to fire repeatedly and eventually leading to paralysis. Todays bed bugs seem to be more resistant to the chemicals that previously killed them. Cases of resistance have been reported in all classes of pests: crop diseases, human diseases, weeds, rodents, and insects, with crises in insect control beginning shortly after the introduction of pesticide use in the 20th century. Why do insect pests become resistant so readily to the pesticides used for control?.
The use of pesticides widely and frequently, genetic heterogeneity among the insect population, and the process of natural selection all play a role in the fast evolution of pesticide resistance.
Due to natural selection, pest insects develop a resistance to insecticides. The insects that are most vulnerable to pesticides die out when pesticides are employed to manage bug populations, leaving behind the insects that are less vulnerable. These less vulnerable insects eventually reproduce and pass on their resistance to their progeny.
In addition, the extensive and regular use of pesticides can hasten the development of resistance. When pesticides are used frequently and in large quantities, the population of pests that are resistant to them will rise.
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Because there are only 26 letters in the alphabet, we could not give every element and one-letter symbol. We would have run out of letters after element 26 (Iron). To solve this problem, most elements have a two-letter symbol.
When an element has a two-letter symbol, what is the rule that must be followed?
Question 1 options:
Both letters are lower-case.
There is no rule; capitalization has no significance in chemistry.
The first letter is capitalized and the the second letter is lower-case.
Both letters are capitalized.
When an element has a two-letter symbol, the rule is that the first letter is capitalized while the second letter is in lowercase. Option 3.
Writing two-letter symbols of elementsIn writing two-letter symbols of elements, the first letter is usually capitalized while the second letter is retained in lowercase. Some examples are highlighted below:
The Latin name of silver is Argentum. Thus, the symbol of silver is Ag.The Latin name of mercury is Hydrargyrum. Thus, the chemical symbol of mercury is HgLead is PbIron is FeIn other words, the number one rule guiding the writing of two-letter chemical symbols is that the first letter must be in the capital while the second letter would be in lowercase.
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Suppose you are hiking through the woods and see many flowers of different colors, shapes, and sizes. You decide to create a taxonomic key to help you identify the flowers. What
characteristics would you include in the key?
Help me figure out what the answer to this is, organic chemistry confuses me
The name of the compound is 1- methyl cyclopropane.
How do you name the cyclo alkane?
Cycloalkenes are named using the same basic system as alkenes, with a few additional considerations.
Identify the parent hydrocarbon: The parent hydrocarbon is the longest continuous chain of carbon atoms that includes the double bond.
Number the parent chain: Number the carbon atoms in the parent chain such that the double bond has the lowest possible number.
Give the prefix "cyclo-" to indicate the presence of a ring: The prefix "cyclo-" is added to indicate that the parent chain forms a ring.
Indicate the location of the double bond: The location of the double bond is indicated by listing the two numbers of the carbons in the double bond.
Name the alkene: Finally, the suffix "-ene" is added to indicate the presence of a double bond.
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reaction order is always defined in terms of both reactant and product concentrations. True or false?
Answer:
False
Explanation:
Reaction order is always defined in terms of both reactant and product concentrations. True or false?
False. The number of species whose concentration directly influences the rate of reaction is indicated by the sequence of reactions. The reactant concentrations are always used to specify the sequence of the reactions (but not with product concentrations).
The power dependence of the rate on the concentration of each reactant is the definition of the order of reaction. The rate law of a reaction can be used to fully comprehend the composition of the reaction mixture once that rule has been established. In other words, the reaction order is an exponent that increases the concentration of a certain species, and it demonstrates the extent to which this concentration impacts the rate of reaction. Additionally, it shows the range in which the species has a large impact.
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the lone pair of electrons on the nitrogen atom in following compound are located in which atomic orbital
The nitrogen atom in the following molecule has a single pair of electrons that are situated in the sp3 hybrid orbital.
In chemistry, the idea of combining atomic orbitals to create new hybrid orbitals (with varied energies, forms, etc.) suited for the pairing of electrons to form chemical bonds in valence bond theory is known as orbital hybridisation (or hybridization). For instance, the valence-shell s orbital joins with three valence-shell p orbitals to generate four equivalent sp3 mixes that are arranged in a tetrahedral configuration around the carbon atom to connect to four distinct atoms. Hybrid orbital are symmetrically arranged in space and are helpful in the explanation of molecular geometry and atomic bonding characteristics. In most cases, hybrid orbitals are created by combining atomic orbitals with similar energies.
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The pKa values for arginine are: pK1 = 2.17, pK2 = 9.04, pKR = 12.48.
a. Draw the structure of arginine at pH 11.
b. Estimate the pI of arginine. Show your work.
The pKa values for arginine are: pK1 = 2.17, pK2 = 9.04, pKR = 12.48.
a. Structure of arginine at pH 11 is attached in the image below.
b.The pI of arginine can be estimated using the pKa values as follows:
pI = (pK1 + pK2) / 2
In this case:
pI = (2.17 + 9.04) / 2 = 5.605
So, the estimated pI of arginine is approximately 5.605.
Amino acids contain both acidic and basic functional groups. The isoelectric point or pI is the pH of a solution wherein the net charge of the amino acid becomes zero. It can be calculated by taking the average of the pKa values.
Arginine (Arg or A) have 3
pKa values:
pKa(3) =1.82;
pKa(3) = 8.99;
pKa(3) = 12.48
What is the pI for arginine?
10.76
The isoelectric point (pI) of arginine is 10.76, which is the highest among the protein amino acids.
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7. When writing a correct formula for a compound we must balance the
by using the correct subscripts.
When writing a correct formula for a compound we must balance the elements in the compound according to their oxidation state by using correct subscripts.
What are elements and compounds?
Pure chemical elements and compounds can be found in nature. An element is a substance made of the same type of atoms as a compound, whereas a compound is made of various elements mixed together in a specific ratio. The elements iron, copper, hydrogen, and oxygen are a few examples. Compounds include, for instance, salt and water (H2O) (Sodium Chloride - NaCl).
So when writing a correct formula for a compound we must balance the
elements in the compound according to their oxidation state by using correct subscripts.
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roller coasters does energy get transferred or transformed worksheet
A roller coaster basically gets energy transformed from potential energy to kinetic.
What is a roller coaster?An elevated train track with sharp twists, steep slopes, and occasionally inversions is used in roller coasters, which are a type of amusement ride. The rides are frequently found in theme parks and amusement parks around the world. Passengers go along the track in open vehicles.
Furthermore, a roller coaster is an elevated railway with steep ascents and descents that transports people in a train through tight turns and abrupt changes in speed and direction. It is a well-liked leisure activity that can be found as a continuous loop primarily in amusement parks.
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As concentration increases, a solution's vapor pressure______ and its osmotic pressure _________A. increases, increases B. increases, decreases C. decreases, increases D. decreases, decreases E. increases, stays the same
As concentration increases, a solution's vapor pressure decreases and its osmotic pressure increases. Hence, option A is correct.
What happens when concentration increases?Osmotic pressure of a solution is proportional to the molar concentration of solute particles in the solution and as soon as the solute molecules increases, osmotic pressure of solution increase.
When non-volatile solute is dissolved in volatile solvent, vapor pressure of the solvent is reduced. As concentration of the solute increases, then the vapor pressure of the solvent decreases.
Po = pgh= psp log ; where Po is osmotic pressure corresponding to a solution at the bottom of column and solvent pressure p, p is mean density of the column, h is its height.
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what is observed when water (in the presence of an acid) is added to 2-methyl-2-pentene?
When we add the water in the presence of the sulfuric acid to 2-methyl-2-pentene , then the product formed is 2-methyl-2-pentanol.
The sulfuric acid acts as the catalyst, in the reaction when the water to added to the carbon double bond of the 2-methyl-2-pentene molecule. The reaction is expressed as :
CH₃-C = CH₂-CH₂-CH₂ + H₂O + H₂SO₄----> CH₃-C(CH₃) - CH₂ - CH₂ - CH₂
| |
CH₃ OH
2-methyl-2-pentene 2-methyl-2-pentanol
This is an example of the addition reaction. The reaction is the exothermic, that means it releases the heat energy and the hydroxyl group will attached to the carbon atom, that is the alcohol-functional group.
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how many grams in a mg
In the metric system, a milligram equals one gram. a unit being used measuring systems to express weight and mass.
How would a gram have weight or mass?Not weight but mass is measured in milligrams. Mass would be a measurement of how much matter an object contains, whereas weight relates to the earth's gravitational pull on it. Knowing an object's mass is essential since it allows you to determine how so much effort will be needed to move it.
What dimensions does a gram have?A gram is a unit of mass equal to one thousandth of a kilogram, or roughly the amount of one cubic millimeter of water.
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True /False 1. Aluminum chloride is a chemical compound with a chemical formula equivalent to AlCl3 or Al3Cl3.
False; the true sentence is: Aluminum chloride is a chemical compound with the chemical formula equivalent to AlCl3.
What is a chemical compound?
A chemical compound is a substance composed of two or more elements chemically combined in a fixed proportion. An example of a chemical compound is water (H2O), which is composed of two hydrogen atoms and one oxygen atom chemically combined in a fixed ratio.
Chemical compounds have unique properties that are different from the elements that make them up, and they can only be separated into their constituent elements through chemical reactions.
For example, water can be separated into hydrogen and oxygen gas by electrolysis, but these elements cannot be combined to form water unless they are subjected to the right conditions of temperature, pressure, and energy.
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A system that does no work but which transfers heat to the surroundings has ___________________.
Answer
a. q < 0, ?E > 0
b. q > 0, ?E < 0
c. q > 0, ?E > 0
d. q < 0, ?E < 0
e. q < 0, ?E = 0
A system that does no work but which transfers heat to the surroundings has , the correct option is d) q < 0 , ΔE < 0.
The expression between the heat , the work and the internal energy is as follows :
ΔE = q + w
If no work is done by the system means w will be zero, The formula for the internal energy is as follows :
ΔE = q + w
ΔE = -q + 0
ΔE = -q
The internal energy is less than zero and the value of the heat is less than the zero.
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what is the molality of ethanol in a solution made by dissolving 14.6 g of ethanol, c2h5oh, in 53.6 g of water?
The molality of the ethanol in the solution is 5.89 mol/kg
The quantity of a material dissolved in a given mass of solvent is known as its molality (m), also known as molal concentration. The moles of a solute per kilogram of a solvent are how it is defined.
Molal concentration is another name for molality. It is a measurement of a solution's solute concentration. Solute and solvent are the two elements that make up the solution.
From the given information:
mass of ethanol = 14.6 g
mass of water = 53.6 g
The number of moles of ethanol is:
= 14.6 g/46.07 g/mol
= 0.316 mol of ethanol
There are 1000 g in 1 kg of water. In 53.6 g of water, there is 0.0536 kg of water.
Therefore, the molality of ethanol
=0.316/ 0.0536
=5.89 mol/ kg
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A half-cell containing Hg2 +2 and Hg is connected to a half-cell containing Mg+2 and Mg to form a voltaic cell. Determine the proper direction for each half-cell reaction to assure a spontaneous, complete cell reaction. Find the value of the complete cell electrode potential (E°).
Answer:
Look up the standard reduction potentials for
Br and Mg. I find the following:Mg2+ +2e-=>
Mgls) E = -2.38 VBr2() +2e-==> 2Br-(aq) E°
calculate the ph of a 6.5×10−2 m solution of butyric acid.
pH of a 6.5 × 10^-2 M solution of butyric acid is 6.07 and the calculation part is below.
The pH of a 6.5 × 10^-2 M solution of butyric acid can be calculated as follows:
Calculate the concentration of hydronium ions (H3O+) in the solution:
Butyric acid (HC4H7O2) is a weak acid, which means that only a small fraction of it dissociates into its ions in solution. The dissociation reaction can be represented as follows:
HC4H7O2 + H2O ⇌ H3O+ + C4H7O2-
The concentration of hydronium ions can be calculated using the acid dissociation constant (Ka) for butyric acid and the initial concentration of butyric acid:
Ka = [H3O+][C4H7O2-] / [HC4H7O2]
[H3O+] = Ka * [HC4H7O2] = 1.3 × 10^-5 * 6.5 × 10^-2 = 8.45 × 10^-7
Calculate the pH:
The pH of a solution is defined as the negative logarithm of the hydronium ion concentration:
pH = -log[H3O+] = -log(8.45 × 10^-7) = 6.07
So, the pH of a 6.5 × 10^-2 M solution of butyric acid is 6.07.
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The chemical equation below shows the reaction between tin (Sn) and hydrogen fluoride (HF).
Sn + 2HF Right arrow. SnF2 + H2
The molar mass of HF is 20.01 g/mol. How many moles of Sn are required to react completely with 40 g of HF?
1 mole
2 moles
3 moles
4 moles
Answer:
1 mole of Sn
Explanation:
The balanced equation tells us that 2 moles of HF react with every 1 mole of Sn. That's a molar ratio of 1/2. We need half as many moles of Sn as we have of HF. Lets determine the moles of HF that are in 40 g of the material. The molar mass of HF is (1 + 19) = 20 grams/mole.
40 grams of HF means we have 2 moles of HF: (40g HF)/(20 grams/mole HF) = 2 moles HF. Since the molar ratio is 1/2, we only need 1 mole of Sn for this reaction.
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Changes in precipitation and snowmelt patterns, withdrawal of ground water for drinking, irrigation, and other human uses, and impervious paved surfaces that prevent precipitation from recharging ground water are all stressors that can deplete aquifers. It may take thousands of years to replenish some deep aquifers.
What are the two main causes of groundwater pollution?There are two types of groundwater contaminants: point sources and distributed, or non-point sources. Point sources include landfills, leaking gasoline storage tanks, leaking septic tanks, and accidental spills.
Deforestation, unscientific agricultural methods, chemical effluents from industries, and a lack of sanitation all contribute to groundwater pollution, rendering it unusable.
Thus, Some deep aquifers may take thousands of years to fill again.
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