The formula for pH at a weak acid-strong base titration's equivalence point must be used to determine the pH at each stage of the titration:
[tex]pH = pK_a + log \frac{[A^-]}{[HA]}[/tex]
where pK a is the weak acid's acid dissociation constant, [A-] is the concentration of the acid's conjugate base, and [HA] is the acid's concentration.
The weak acid (formic acid) is at a concentration of 0.100 M at the start of the titration (0 mL of additional base), and the conjugate base (formate ion) is at a concentration of 0.00 M, resulting in a pH of:
[tex]pH = pK_a + log \frac{[A^-]}{[HA]} [/tex]
[tex]= pK_a + log \frac{0}{0.100} [/tex]
= pK_a + log(0)
We are unable to determine the pH at this time since the logarithm of 0 is undefinable.
The weak acid concentration falls as the titration goes along and more base is added, while the conjugate base concentration rises. The concentration of the weak acid is 15.0 mL when 15.0 mL of additional base is used.
[tex]0.100 M - \frac{0.200 M \times15 mL }{50 mL} [/tex]
= 0.080 M,
and the concentration of the conjugate base is
[tex] \frac{0.200 M \times 15 mL}{50 mL} [/tex]
= 0.060 M. The pH at this point is:
[tex]pH = pK_a + log \frac{[A^-]}{[HA]}[/tex]
[tex]= pK_a + log \frac{0.060}{0.080} [/tex]
= pK_a + log(0.75)
= pK_a + (-0.122)
You may use the same formula and the appropriate numbers for [A-] and [HA] to determine the pH at the other points in the titration.
It should be noted that the pH at the equivalence point (when the ratio of acid to base is equal) will be the same as the weak acid's pK a. Since the concentration of the weak acid is zero at the equivalence point, the pH is:
[tex]pH = pK_a + log \frac{[A^-]}{[HA]}[/tex]
[tex]= pK_a + log \frac{[A^-]}{0}[/tex]
[tex]= pK_a + log([A^-])[/tex]
The pH at the equivalence point will be lower than the pK a of the weak acid since the logarithm of a number less than 1 has a negative value. Beyond the equivalence point, adding more base will cause the pH to continue to drop.
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how did the study of the atom contribute to our understanding of the periodic table of the elements?(1 point) responses
The study of the atom contribute to our understanding of the periodic table of the elements by providing information about the structure of the atom and the arrangement of the elements.
What does research into the atom show?This study reveals how the elements are arranged.
Atomic weight (number of protons).Atomic weight (number of protons and neutrons).electron arrangement.Understanding atoms let scientists learn more about the building blocks of elements, which helped organize the periodic table. Scientists were able to organize the periodic table using the atomic weights and atomic numbers obtained from experiments that revealed the properties of individual atoms. Which is a system of categorizing the elements based on their atomic qualities, by comprehending the structure of the atom and the arrangement of the components.
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at what temperature in k will 0.950 moles of oxygen gas occupy 7.50 l and exert 2.60 atm of pressure
At 25 K temperature, 0.950 moles of oxygen gas occupy 7.50 l and exert 2.60 atm of pressure.
Ideal gas law will be used to calculate the temperature -
PV = nRT, where Pis pressure, V is volume, n is number of moles, R is gas constant and T is temperature. The value of gas constant to be used in the formula is 0.082 L atm/mol/K
Temperature = (2.60×7.5)/(0.082×0.95)
Performing multiplication in both numerator and denominator on Right Hand Side of the equation
Temperature = 19.5/0.78
Performing division on Right Hand Side of the equation
Temperature = 25 K
Thus, the temperature of oxygen gas is 25 K.
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The diagram illustrates an experiment where baking soda was
added to a container of vinegar. After five minutes, the balloon on
the top of the bottle started expanding. Explain what happened and
how this experiment demonstrates the Law of Conservation of
Matter.
A reaction between an acid and a base occurs when vinegar and baking soda are combined. Baking soda serves as the base, and vinegar is the acid. A gas known as carbon dioxide bubbles and foams as a result of this reaction between the two. Because there is nowhere else for this gas, it expands the balloon, resulting in the self-inflating balloon.
What happens when vinegar and baking soda are combined in a bottle and a balloon is inserted into the bottle's mouth?SCIENCE: Carbon dioxide is a gas produced when baking soda and vinegar are combined. The gas starts to extend in the jug and begins to expand the inflatable. The balloon will expand in size the more gas produced.
What is the balloon experiment's conclusion?Because their particles travel at high speeds in all directions, gases expand quickly. Since the carbon dioxide gas has nowhere else to go, it begins to fill the balloon as it fills the bottle. The balloon expands as the carbon dioxide gas fills it.
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citrate and oxalate are usually added to embalming fluids to act as question 90 options: a) surfactants b) buffers c) preservatives d) vehicles
Option (c) is correct. Citrate and oxalate are usually added to embalming fluids to act as Preservatives.
A Preservative is defined as a substance or a chemical that is added to products such as food products, beverages, pharmaceutical drugs, paints, biological samples, cosmetics, wood, and many other products to prevent decomposition by microbial growth or by undesirable chemical changes. preservation is implemented in two modes, chemical and physical. Chemical preservation entails adding chemical compounds to the product. Physical preservation involves the processes such as refrigeration or drying. Preservatives are of various types that are suited to certain products and are effective against specific chemical changes.
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In Chemistry class, students have been discussing the differences between physical and chemical changes.
The students carried out several procedures and recorded their observations. The students determined that
one of the procedures is an example of a physical change, but not a chemical change.
Which of the following tests conducted shows a physical change?
A A colorless liquid changes to blue when another solution is added.
B Two clear liquids are combined, and the beaker becomes cloudy.
A cube of metal aluminum is flattened to create aluminum foil.
D Two clear liquids are combined, and the beaker becomes hot.
C
The option that shows a physical change would be a cube of aluminum metal being flattened to create aluminum foil. Option C.
What are physical changes?In chemistry, physical changes refer to reactions that only alter the physical properties of substances and not their chemical properties.
It is opposed to chemical changes which are changes that alter the chemical properties of substances, often along with their physical properties.
The changes to the color of a liquid when another liquid is added is a chemical change because the original color may not be recoverable.
The combination of two clear liquids resulting in a cloudy solution is a chemical change. So also is the combination of two clear liquids resulting in the beaker becoming hot.
The only physical change is the flattening of an aluminum cube to create aluminum foil. The chemical properties of the aluminum remain intact.
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a radioactive nuclear isotope spontaneously decays with a half-life of 63.3 min. if you begin with a 589 mg sample of that isotope, how much of it will be left after 3.40 hours?
The amount of sample left after 3.40 hours will be 338 mg.
T= Half life x log (m./m)/log(2)
You could use this formula:
Where Th = half-life.
M. = the beginning mount
M = the ending amount
T= 3.40 hours
Half life = 2.4463.3 min
M.= 0.589g
m= ?
Then plug the number into the given equation:
T= 2.4463 x log(0.589 /m)/log(2)
T= 2.4463 x log (0.589/m) /log(2)
T= 2.4463× -0.22/ log m× 0.3
3.4× 60 = 2.4463× log m ×0.3
log m= 3.4× 60/ 2.4463 ×0.3
log m= 279.4
m= 2.511 g = 251mg
So the amount left after the 3.40 hours will be = 589- 251 mg = 338 mg of the sample.
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xx grams of water were added to 80 grams of a strong solution of acid. if as a result, the concentration of acid in the solution became 1y1y times of the initial concentration, what was the concentration of acid in the original solution? (1) x
The concentration of acid in the original solution is equal to (80/ (xxx + 80)) * (1/1y1y).
What is concentration?Concentration is the ability to focus one's attention on a particular task or activity. It involves the ability to block out distractions and other stimuli in order to concentrate on the task at hand. Concentration requires mental effort and discipline, and it is an essential skill for success in many areas of life. It is particularly important in education, as it helps students to stay focused and retain information. Concentration can also be beneficial for athletes, allowing them to stay focused and in the zone during competition. Finally, it is important for anyone attempting to achieve any sort of goal, as it helps to stay focused and motivated in order to reach that goal.
The concentration of acid in the original solution can be calculated using the following formula:
Concentration = (Mass of Acid/Total Volume of Solution)
Given that 80g of acid was added to the solution, and the resulting concentration of acid is 1y1y times stronger, we can calculate the initial concentration of acid.
Original Concentration = (80 g/80 g + xxx g) * (1/1y1y)
Original Concentration = (80 g/ (80 + xxx)) * (1/1y1y)
Original Concentration = (80/ (80 + xxx)) * (1/1y1y)
Original Concentration = (80/ (xxx + 80)) * (1/1y1y)
Therefore, the concentration of acid in the original solution is equal to (80/ (xxx + 80)) * (1/1y1y).
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if you are bombarded with 1.00 mol of photons with a wavelength of 390. nm, what amount of energy, in kilojoules per mole of photons, are you being subjected to?
The amount of energy required is 319kJ mol ⁻¹.
Wavelength is the distance between identical points in adjacent cycles of a waveform signal propagating in space or along a wire. In wireless systems, this length is usually expressed in meters, centimeters, or millimeters. Wavelength is the distance between two wave crests and the same for wave troughs.
Wavelength can be defined as the distance between two consecutive peaks or valleys. Measured in the direction of the wave. Wavelength is the distance between two wave crests and the same for wave troughs. Frequency is the number of oscillations that pass through a particular point in one second, measured in cycles per second.
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methanol (ch3oh) can be made by the controlled oxidation of methane: ch4(g)+12o2(g)→ch3oh(g)
The standard Gibbs free energy change for the reaction at 25°C is approximately - 111.158 KJ/mol.
To calculate the standard Gibbs free energy (ΔG°) at 25°C for the reaction CH4(g) + 1/2 O2(g) → CH3OH(g), we can use the formula:
ΔG° = ΔH° - TΔS°
where ΔH° is the standard enthalpy change for the reaction, T is the temperature in kelvin, and ΔS° is the standard entropy change for the reaction.
Assigning the respective values given in the question, we have:
ΔG° = (-126.4 kJ/mol) - (298 K)(-51.1 J/mol*K)
= -126.4 kJ/mol - (-15.2418 KJ/mol)
= - 111.158 KJ/mol
Therefore, the standard Gibbs free energy change for the reaction at 25°C is approximately - 111.158 KJ/mol. This value tells us that the reaction is thermodynamically favorable and will tend to occur spontaneously under standard conditions.
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Complete question:
Methanol, CH3OH, can be made by oxidation of methane in limited quantity.
CH4(g) + 1/2 O2(g) CH3OH(g)
ΔH = -126.4
ΔS = -51.1
Calculate ΔG° at 25°C.
if a radiometric analysis of an isotope and its stable element yielded 50% of each, how many half-lives would have occurred? a. 5 b. 4 c. 3 d. 2 e. 1
The half-lives that have occurred if a radiometric analysis of an isotope and its stable element yielded 50% is 1. Hence, the option E is correct.
The half-life of a chemical reaction can be described as the time taken for the concentration of a given reactant to reach 50% of its initial concentration (i.e. the time taken for the reactant concentration to reach half of its initial value). Half-live of a reaction is denoted by the symbol 't(1/2)' and is usually expressed in seconds.
Radiometric analysis is one of the oldest methods used for the quantitation of drug molecules. Radiometric analysis generally involves quantitation of radiation from beta-emitting radioactive isotopes such as ¹⁴C, ³H or ³²P.
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8) the above molecule is composed of/contains ? a) riboflavin b) deoxyribose c) phosphodiester bonds d) a and c only e) a and b only
The correct option is e)t a and b only. Riboflavin and deoxyribose are both components of the molecule, while phosphodiester bonds link the two together.
What is molecule?Molecule is a group of two or more atoms held together by covalent bonds. The atoms that make up a molecule can be from the same element, such as two hydrogen atoms, or from different elements, such as a hydrogen atom and an oxygen atom. Molecules can be as small as two atoms or as large as thousands of atoms. The properties of a molecule depend on how the atoms are arranged and the type of bonds that are formed.
Riboflavin is a B vitamin found in foods such as milk, eggs, and green vegetables, while deoxyribose is a five-carbon sugar that forms the backbone of DNA. Phosphodiester bonds are covalent chemical bonds which link the two components of the molecule together.
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a compound contains 27.04% sodium, 16.48% nitrogen and 56.52% oxygen what is the empirical formula of the compound?
NNaO3 is the empirical formula of the compound, a compound contains 27.04% sodium, 16.48% nitrogen and 56.52% oxygen
⇒Find molar mass of each component: N=14.0067, Na=22.98976928, O=15.9994
⇒Convert to moles: N=1.1765797796769, Na=1.1761753530743, O=3.5295073565259
⇒Find smallest mole value: 1.1761753530743
⇒Divide all components by the smallest value: N=1.0003438489011, Na=1, O=3.0008343120781
⇒Round to closest whole numbers: N=1, Na=1, O=3
⇒Combine to get the empirical formula: NNaO3,
The scientific name for nitrogen is N, and it is an element that has no colour nor smell. The ground beneath our feet, the water we drink, and the air we breathe all contain nitrogen. In reality, nitrogen makes up the majority of the atmosphere on Earth, making up around 78% of the atmosphere.
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irradiation of quartz that contains traces of aluminum will produce what gem? group of answer choices jadeite cairngorm garnet amphibole chrysoberyl
irradiation of quartz that contains traces of aluminum will produce cairngorm
To produce the morion variety of peaty quartz, any quartz can be irradiated. Furthermore, when exposed to 0.5 to 1.5 mrd of ores 60, gamma, X-ray, or electron radiation, all quartz would then turn a blackish or brownish colour. However, this will not result in uniform colour. Irradiated smoky quartz does not present any radiation risk. Irradiating a crystal causes some energy to accumulate in the crystalline structure, which can change the optical characteristics, most notably the colour. For centuries, gem nutrients have indeed been prized and sought after. If they are transparent, they can be segmented and refined to create attractive stones to be used in jewellery and other ornamental purposes
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a constant current of 0.912 a is passed through an electrolytic cell containing molten mgcl2 for 17.5 h. what mass of mg is produced?
An electrolytic cell holding molten mgcl2 is subjected to a continuous current of 0.912 a for 22.5 hours mg is generated
the act of calculating,
electrolytic cell holding molten mgcl2
0.912 A is the constant current (I).
time (t) = 22.5 hours = 81,000 seconds
Mg's molar mass is 24.31 g/mol.
in which there were electrons in reaction 2
Mass (w) is calculated as (molar mass (I) / t / nF =
(w) = 24.31 g/mol, 0.912 A, 81000 sec/2, 96500, and 9.35 gram.
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for each of the reactions at constant pressure, determine whether the system does work on the surroundings, the surroundings does work on the system, or essentially no work is performed.
Answer:
It is not possible to accurately determine whether the system or the surroundings performs work in a chemical reaction without more information about the specific reaction and the conditions under which it occurs.
In general, the work done in a chemical reaction can be affected by several factors, including the pressure, volume, and temperature of the system, as well as the nature of the reactants and products. Some reactions may result in the system doing work on the surroundings, such as when gases expand and do work on their surroundings by pushing against a piston or other external object. Other reactions may result in the surroundings doing work on the system, such as when gases are compressed and their surroundings do work on them. Still other reactions may result in essentially no work being performed, such as when the reactants and products are in equilibrium or when the volume of the system remains constant.
Without more information about the specific reaction in question, it is not possible to accurately determine whether the system or the surroundings performs work.
qualitatively estimate the relative melting points for each of the solids, and rank them in decreasing order.
The relative melting points for each of the solids, and rank them in decreasing order Graphite> sodium chloride> solid ammonia.
What determines melting point?More energy is required to overcome them the strong the forces of interaction between the particles are. The melting point rises with increasing energy demand. Thus, a crystalline solid's melting temperature serves as a barometer for stability of it's own lattice.
Why is the melting point important?A solid's freezing temperature is a physical characteristic that can be used to identify a substance. In reality, a solid typically melts across a wide temperature range as opposed to at a single, set temperature. For this reason, speaking of a range of melting point is more useful.
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PLEASE HELP!! DUE SOON ILL GIVE BRAINLIST
A teacher divides her class into groups and assigns each group the task of measuring the length of the same object three times. The teacher already knows that the length of the object is 78.5 mm
based on the results the students record, which group makes the most accurate measurements of the object?
A. Group D: 75.0 mm,75.0 mm, 75.0 mm
B. Group B: 75.5 mm, 75.00 mm, 74.8 mm
C. Group C: 78.5 mm, 72.9 mm, 79.8 mm
D. Group A : 78.5 mm, 77,5 mm, 79.5 mm
There are two terms that are related to measurements, one is accuracy and other is precision. Therefore, Group A makes the most accurate measurements of the object. The correct option is option D.
What is accuracy?The capacity of an instrument to measure an exact number is known as accuracy. In other words, it refers to how closely the measured value resembles a reference or genuine value.
Small readings can be taken to determine accuracy. The modest reading decreases the calculation's inaccuracy. Group A makes the most accurate measurements of the object.
Therefore, Group A makes the most accurate measurements of the object. The correct option is option D.
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Which of the following best explains why atomic radius decreases from left to right across a period?
Atomic radius decreases because the effective nuclear charge increases. Option C
What is the atomic radius?We know that the atomic radius can be defined as the measured distance between the nucleus and the electrons that lies far outside in the outermost shell of the atom.
We know that the atomic radius is one of the periodic properties that we have in the atom. It is a periodic property that decereases across the period but increases adown the group.
As we add more protons to the nucleus of the atom, the attractive forces would increase and the atomic radius would now tend to decrease across the period for the atoms of elements.
Thus, the greater the effective nuclear charge that we have in the atom, the lesser the atomic radius of the atom.
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Kinetic energy___ the speed and/or the masse of a raised object
Kinetic energy directly proportional to the speed and/or the masses of a raised object.
What is kinetic energy?An item possesses kinetic energy when it is in motion. Applying force is necessary if we wish to accelerate an item. We must put forth effort in order to apply a force. Once the job is finished, energy is transferred to the item, which then moves at a new, constant speed.
The amount of kinetic energy that is transmitted is determined by the mass and speed attained. The relationship between kinetic energy and an object's mass and squared velocity is given by K.E. = 1/2 mv².
Thus, Kinetic energy directly proportional to the speed and/or the masses of a raised object.
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how would you change the concentrations of the solutions at each electrode in the voltaic cell below in order to increase the cell potential
The potential of the cell helps to evaluate the voltage difference between two half-cells.
Changing the concentration of one solution in the cell will increase the voltage potential of the cell because putting the system further out of equilibrium.
A chemical reaction is affected by three main variables mainly temperature, surface area, and concentration. In an electrochemical cell, the higher concentration allows the increase in voltage difference.
The higher concentration of reactant moves the reaction in the forward direction to react at a higher pace, and as a result, higher voltage is observed.
A concentration cell acts to dilute the more concentrated solution and concentrate the more dilute solution, creating a voltage as the cell reaches an equilibrium.
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what is the concentration, in m/v percent, of a solution prepared from 50. g nacl and 2.5 l of water?
The concentration, in m/v percent, of a solution prepared from 50. g nacl and 2.5 l of water is 2 %.
The mass/volume percent is the ratio of a solution's total volume to the mass of the solute that makes up that solution. Since this type of concentration has been expressed as a percentage, the given proportion should be multiplied by 100.
The calculation if concentration is shown as:
It can be calculate as follows:
% NaCl = Mass of NaCl / Total mass × 100 %
% NaCl = 50 gram / 2500 × 100 %
% NaCl = 2 %.
As a result, the solution made from 50 g of nacl and 2.5 l of water will have a 2% concentration.
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Which among the chemicals is NOT an approved sanitizer for kitchen tools
D. Steam
and equipment?
A. Chlorine B. Iodine C. Quaternary ammonium D. Timsen
if a solution containing 33.17 g of lead(ii) perchlorate is allowed to react completely with a solution containing 8.564 g of sodium sulfate, how many grams of solid precipitate will be formed?
18.3 g of solid precipitate formed during the reaction.
Formula of lead(ii) perchlorate = [tex]Pb(ClO4)_{2}[/tex]
Formula of sodium sulfate = [tex]Na_2(SO_4)[/tex]
Reaction of lead(ii) perchlorate and sodium sulfate
[tex]Pb(ClO4)_{2}[/tex] + [tex]Na_2(SO_4)[/tex] ----------> [tex]PbSO_4(s)[/tex] + [tex]2Na(ClO4)_{2}[/tex]
moles of [tex]Pb(ClO4)_{2}[/tex] = [tex]\frac{given mass}{ Molar mass}[/tex]
molar mass of [tex]Pb(ClO4)_{2}[/tex] =207+(35.5+ 16*4)*2
molar mass of [tex]Pb(ClO4)_{2}[/tex] =207+ 99.5*2
molar mass of [tex]Pb(ClO4)_{2}[/tex] =406
given mass = 33.17g
moles of [tex]Pb(ClO4)_{2}[/tex] = [tex]\frac{given mass}{ Molar mass}[/tex]
moles of [tex]Pb(ClO4)_{2}[/tex] = [tex]\frac{33.17}{406}[/tex]
moles of [tex]Pb(ClO4)_{2}[/tex] = 0.0817 moles
molar mass of [tex]Na_2(SO_4)[/tex] = 2*23+ 32+ 4*16
molar mass of [tex]Na_2(SO_4)[/tex] = 46+32+64
molar mass of [tex]Na_2(SO_4)[/tex] = 142
moles of [tex]Na_2(SO_4)[/tex] = [tex]\frac{given mass}{ Molar mass}[/tex]
moles of [tex]Na_2(SO_4)[/tex] = [tex]\frac{8.564}{142}[/tex]
moles of [tex]Na_2(SO_4)[/tex] = 0.0603 moles
since in the above reaction [tex]Pb(ClO4)_{2}[/tex] is the solid precipitate so we have to find the weight of [tex]PbSO_4(s)[/tex] formed after the reaction.
Given that the reaction is complete so one of the 2 reactant must completely ends since [tex]Na_2(SO_4)[/tex] have less number of moles than [tex]Pb(ClO4)_{2}[/tex] so , [tex]Na_2(SO_4)[/tex] will disappear and hence according to Stoichiometry same number of moles of [tex]PbSO_4(s)[/tex] will form
so number of moles of [tex]PbSO_4(s)[/tex] formed = 0.0603
so, the weight of [tex]PbSO_4(s)[/tex] formed = number of moles formed * molar mass of [tex]PbSO_4(s)[/tex]
so weight of [tex]PbSO_4(s)[/tex] formed =0.0603 * 303
weight of [tex]PbSO_4(s)[/tex] formed= 18.27 g ≈ 18.3 g
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Which one of the following is not an agent of weathering?
SoilGlaciersWindRain Water
Answer: Soil
Explanation:
Wind, rain, water, and glaciers are all agents of weathering because they can erode materials. Even though Glaciers need certain conditions they can still do damage to the surface of the earth. While soil is what gets eroded or sometimes is the product of erosion occurring.
given that s is the central atom, draw a lewis structure of osf4 in which the formal charges of all atoms are zero.
A Lewis structure shows the valence electrons surrounding the atoms.
Your structure has two problems:It shows too many valence electrons
It violates the octet rule for O — there are 10 electrons around the O atom.
Count the valence electrons in the trial structure
5 BP + 15 LP = 10 + 30 = 40 electrons
3. Check the number of valence electrons available1 S = 1 × 6 = 6 electrons
1 O = 1 × 6 = 6
4 F = 4 × 7 = 28
TOTAL = 40 electrons
The trial structure has the correct number of electrons.
4. Determine the formal charge on each atom.To get the formal charges, we cut the covalent bonds in half.
Each atom gets the electrons on its side of the cut.
Formal charge = valence electrons in isolated atom - electrons on bonded atom
FC = VE - BE
(a) On S
VE = 6
BE = 5 bonding electrons = 5
FC = 6 - 5 = +1
(b) On O:
VE = 6
BE = 3 LP(six electrons) + 1 bonding electron = 7
FC = 6 - 7 = -1
(c) On F:
VE = 6
BE = 3 lone pairs(6 electrons) + 1 bonding electron = 6 + 1 =7
FC = 7 - 7 = 0
5. Minimize the formal chargesWe must rearrange the valence electrons so that S gets one more and O gets one fewer.
6. Recalculate the formal charges(a) On S
VE = 6
BE = (3 bonding electrons) = 6
FC = 6 - 6 = 0
(b) On O:
VE = 6
BE = 2 LP(four electrons) + 2 bonding electrons = 6
FC = 6 - 6 = 0
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Question is Incomplete:
Given that S is the central atom, draw a Lewis structure of OSF4 in which the formal charges of all atoms are zero. Draw the molecule by placing atoms on the grid and connecting them with bonds. Include all lone pairs of electrons.
the decay rate for a radioactive isotope is 5.4 percent per year. find the half-life of the isotope.
The half-life of a radioactive isotope is the amount of time it takes for half of the atoms in a sample to decay.
What is radioactive isotope?A radioactive isotope is an unstable form of an element that emits radiation as it decays. It is produced when a neutron is added to the nucleus of an atom, making it unstable and prone to radioactive decay. Radioactive isotopes are used in a variety of medical, scientific and industrial applications. In medicine, they are used to diagnose and treat diseases, while in industry they are used to detect flaws in materials. In scientific research, they are used to measure age and composition of materials.
Therefore, the half-life of this isotope is 12.75 years, since it takes 5.4 percent of the atoms in a sample to decay per year. This means that if we start with a sample of 100 atoms, after 12.75 years, only 50 atoms would remain in the sample. After 25.5 years, only 25 atoms would remain, and so on. This can be calculated by taking the natural log of 2 and dividing it by the decay rate of the isotope, which in this case is 5.4%.
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copper (63.546 amu) has two isotopes: 63 cu (62.9396 amu) and 65 cu (64.9278 amu). what percent of copper atoms are 65 cu?
Isotopes are two or more atom types that share the same atomic number (number of protons in their nuclei), location in the periodic table, and chemical element. Still, they have different nucleon numbers (mass numbers) as a result of having a different number of neutrons in their nuclei. Although the chemical properties of each isotope of a given element are nearly identical, they differ in their atomic weights and physical characteristics.
Along with 27 radioisotopes, copper (29Cu) has two stable isotopes: 63Cu and 65Cu. The radioisotope 67Cu, with a half-life of 61.83 hours, is the most durable; 54Cu, with a half-life of roughly 75 ns, is the least stable. A minute or less is the average half-life.
The percentage of copper atoms in 65 Cu is 25%.
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a compound is a chemical substance with a given set of properties that cannot be broken down into substances with other properties. true false
Lithium ha two iotope with ma number 6 and 7. If the relative atomic ma of
lithium i 6. 94, determine the percentage abundance of each iotope
The percentage abundance of lithium 6 is 6% and percentage abundance of lithium 7 is 94%.
Relative atomic mass is defined as the ratio of the average mass of atoms of a chemical element in a given sample to the atomic mass constant. The atomic mass constant is defined as being 1/12 of the mass of a carbon-12 atom.
R.A.M = (Mass.no ×Abundance) / (Total abundance)
Let the abundance of Li-6 be x
Relative abundance of Li-7 will be 100−x.
6.94 = (6 × x)+ 7(100−x) / 100
6x + 700 – 7x = 694
X = 6%
Li-6 has 6%, Li-7 has 94% because the sum of the percent natural abundances of all the isotopes of any given element must total 100%. atoms that have the same atomic number (number of protons), but different mass numbers that is number of protons and neutrons are called isotopes.
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each drug has chemical and physical properties that must be considered when developing the pharmaceutical formulation, these include:
That the breakdown or dissolution of the drug after administration constitutes the pharmaceutic phase of drug activity, which must occur in medicine composition.
Describe healthcare.
Healthcare can be simply defined as organised medical care provided to an individual, group, or even community by a physician, nurse, or other qualified healthcare practitioner.
However, medically related Patients may contract infections from bacteria, viruses, fungi, and other pathogens while receiving therapy for another ailment.
For this reason, the primary goal of healthcare is to improve quality of life and healthy living through the provision of high-quality healthcare services.
As a result, the nurse is aware that the pharmaceutic phase of drug action, which must occur after administration of the medication, is the drug's breakdown or dissolution.
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