Answer:
8.09x10⁻⁵M of Fe³⁺
Explanation:
Using Lambert-Beer law, the absorbance of a sample is proportional to its concentration.
In the problem, the Fe³⁺ is reacting with KSCN to produce Fe(SCN)₃ -The red complex-
The concentration of Fe³⁺ in the reference sample is:
4.80x10⁻⁴M Fe³⁺ × (5.0mL / 50.0mL) = 4.80x10⁻⁵M Fe³⁺
Because reference sample was diluted from 5.0mL to 50.0mL.
That means a solution of 4.80x10⁻⁵M Fe³⁺ gives an absorbance of 0.512
Now, as the sample of the lake gives an absorbance of 0.345, its concentration is:
0.345 × (4.80x10⁻⁵M Fe³⁺ / 0.512) = 3.23x10⁻⁵M.
As the solution was diluted from 20.0mL to 50.0mL, the concentration of Fe³⁺ in Jordan lake is:
3.23x10⁻⁵M Fe³⁺ × (50.0mL / 20.0mL) = 8.09x10⁻⁵M of Fe³⁺
The concentration of Fe³⁺ in Jordan Lake is = 8.09* 10⁻⁵ M
According to Lambert-Beer law ;The rate of absorbance of a sample is directly proportional to concentration of the sample
The reaction that produces a red complex
Fe³⁺ + KScN ----> Fe ( SCN )₃ ( red complex )
First step: Determine the Concentration of Fe³⁺ in reference sample
= 4.80x10⁻⁴ * ( 5.0 / 50.0 ) = 4.80 * 10⁻⁵M
reference sample was diluted from 5.0 mL to 50.0 mL
∴ Concentration of 4.80 * 10⁻⁵M has an absorbance = 0.512
Given that Lake sample absorbance = 0.345
Next step : Determine the concentration of the lake sample
Concentration of lake sample :
= absorbance of lake sample * ( conc of reference sample / absorbance )
= 0.345 * ( 4.80* 10⁻⁵ / 0.512 ) = 3.23* 10⁻⁵M.
Final step : Determine the concentration of Fe³⁺ in Jordan lake
= 3.23 * 10⁻⁵ * ( 50.0mL / 20.0mL) = 8.09* 10⁻⁵ M
Note : Solution was diluted from 20.0 mL to 50.0 mL
Hence we can conclude that The concentration of Fe³⁺ in Jordan Lake is = 8.09* 10⁻⁵ M .
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Predict the products of the following elimination reaction, and draw the major product formed. Make sure to consider the stereochemistry of the reaction. 3-chloro-3-methylpentane reacts with sodium tertbutoxide in tertbutanol.
Predict the products of the following elimination reaction, and draw the major product formed. Make sure to consider the stereochemistry of the reaction. 3-chloro-3-methylpentane reacts with sodium ethoxide in ethanol.
Answer:
see explanation below
Explanation:
In the first case, we have a reaction where we have the 3-chloro-3-methylpentane reacting with t-butoxide. The t-butoxide is a very voluminous base, so the strength of substracting a hydrogen atom is reduced. Therefore, the reaction taking place here will be an E2 but instead of substracting the hydrogen from the carbons 2 or 4, it will substract it from the methyl group, cause it has less steric hindrance there and the reaction will go faster.
In the second case, the sodium ethoxide is a strong base, so it will rapidly substract an atom of hydrogen from carbon 2 or 4 to form the (Z) - 3 - methyl - 2- pentene and the substitution product.
Look picture for mechanism and products.
Given the equation 2KCIO3(s)=2KCI(s) + 3O2(g). A 3.00-g sample of KCIO3 is decomposed and the oxygen at 24 degrees C and 0.982 atm is collected. What volume of oxygen gas will be collected assuming 100% yield?
Answer:
0.912 L or 912 mL
Explanation:
M(KClO3) = 122.55 g/mol
3.00 g KClO3 * 1 mol/122.55 g = 3.00/122.55 mol =0.02449 mol
2KCIO3(s)=2KCI(s) + 3O2(g)
from reaction 2 mol 3 mol
given 0.02449 mol x
x = 0.02449*3/2 =0.03673 mol O2
T = 24 + 273.15 = 297.15 K
PV = nRT
V= nRT/P = (0.03673 mol*0.082057 L*atm/K*mol*297.15 K)/0.982 atm =
= 0.912 L or 912 mL
A student states that the graduated cylinder contains 150 mL of water his statement is
A. A prediction
B. An observation
C. A theory
D. A hypothesis
The correct answer is B. An observation
Explanation:
An observation is defined as a statement or conclusion you made after observing or measuring a phenomenon, this includes statements based on precise instruments. For example, if you conclude a plant grows 2 inches every month by measuring the plant during this time, this is classified as an observation. The conclusion of the student is also an observation because he concludes this after analyzing the volume of the water in the cylinder through the lines in the graduated cylinder, considering the water is just in the middle of 100 mL and 200 mL which indicates there are 150 mL of water.
Answer:
B. An observation
Explanation:
Hello,
Given the illustration, such statements is considered as an observation, since it came up from something the student realized with his/her own eyes, as in the volumetric cylinder the level of the liquid reached 150 mL of water. Predictions are not observed but assumed, theories are stated when experimentation is already deeply studied and hypothesis are assumptions before experimenting.
Regards.
The decay of a radioactive material is monitored using a Geiger counter. At the start, the count rate is 2000 decays/minute. Four hours later the decay rate is 500 counts/min. What is the half-life of the material?
Answer:
The half-life of the material is 2 years
Explanation:
Given;
initial count rate = 2000 decays/minute
final count rate = 500 counts/min
decay time = Four hours
To determine the half life of the material; we create a simple decay table that matches the decay time and count rates.
time (years) count rate
0 2000 decays/minute
2 1000 decays/minute
4 500 decays/minute
Half life is the time intervals = 2 years
Also using a formula;
[tex]N = \frac{N_o}{(t/2)^2} \\\\N_o-is \ the \ initial \ count\ rate\\\\N-is \ the \ final \ count\ rate\\\\t/_2 - is \ the\ half\ life \\\\N = \frac{N_o}{(t/2)^2} \\\\500 = \frac{2000}{(t/2)^2}\\\\(t/_2)^2 = \frac{2000}{500} \\\\(t/_2)^2 = 4\\\\t/_2 = \sqrt{4} \\\\t/_2 = 2 \ years[/tex]
Therefore, the half-life of the material is 2 years
What is the balanced form of the chemical equation shown below?
Na2SO4(aq) + Sr(NO3)2(aq) → SrSO4(s) + NaNO3(aq)
A. Na2SO4(aq) + Sr(NO3)2(aq)
SISO4(s) + NaNO3(aq)
B. NaSO4(aq) + SINO3(aq) → SSO4(s) + NaNO3(aq)
C. Na2SO4(aq) → SrSO4(s) + 2NaNO3(aq)
Ο Ο
D. Na2SO4(aq) + 2Sr(NO3)2(aq) → 2SSO4(s) + 2NaNO3(aq)
Answer:
C. Na₂SO₄(aq) + Sr(NO₃)₂(aq) → SrSO₄(s) + 2 NaNO₃(aq)
Explanation:
Based on the equation:
Na₂SO₄(aq) + Sr(NO₃)₂(aq) → SrSO₄(s) + NaNO₃(aq)
As you can see, sulfate ions (SO₄) are been replaced for nitrate ions (NO₃). That is a double replacement reaction and is a very important information because 2 NO₃ ions in Sr(NO₃)₂ are producing 1 NO₃ ion. To balance NO₃:
Na₂SO₄(aq) + Sr(NO₃)₂(aq) → SrSO₄(s) + 2 NaNO₃(aq)
1 SO₄ ion in Na₂SO₄ produce 1 SO₄ ion in SrSO₄. And Na and Sr metals are balanced yet. Thus, the balanced form of this chemical equation is:
Na₂SO₄(aq) + Sr(NO₃)₂(aq) → SrSO₄(s) + 2 NaNO₃(aq)What is the oxidation number of nitrogen in N20?
00
O+1
O +2
O +4
Propane (C3H8) burns in a combustion reaction. How many grams of C3H8 are needed to produce 80.3 mols CO2 ?
Answer:
1177.88g of C3H8
Explanation:
We'll begin by writing the balanced equation for the reaction. This is given below:
C3H8 + 5O2 —> 3CO2 + 4H2O
Next we shall determine the number of mole of C3H8 required to produce 80.3 moles of CO2. This is illustrated below:
From the balanced equation above,
1 mole of C3H8 reacted to produce 3 moles of CO2.
Therefore, Xmol of C3H8 will react to produce 80.3 moles of CO2 i.e
Xmol of C3H8 = 80.3/3
Xmol of C3H8 = 26.77 moles
Finally, we shall convert 26.77 moles of C3H8 to grams.
Molar mass of C3H8 = (3x12) + (8x1) = 44g/mol
Mole of C3H8 = 26.77 moles
Mass of C3H8 =..?
Mass = mole x molar mass
Mass of C3H8 = 26.77 x 44
Mass of C3H8 = 1177.88g
Therefore, 1177.88g of C3H8 are needed for the reaction
A semipermeable sac containing 4% NaCl, 9% glucose, and 10% albumin is suspended in a solution with the following composition: 10% NaCl, 10% glucose, and 40% albumin. Assume that the sac is permeable to all substances except albumin. State whether each of the following will (a) move into the sac, (b) move out of the sac, or (c) not move.
glucose: a. moves into sac
water: b. moves out of sac
albumin: c; does not move
NaCl: a; moves into sac
Answer:
Glucose: (a) moves into sac
Water: (b) moves out of sac
Albumin: (c) does not move
NaCl: (a) moves into sac
Explanation:
A semi-permeable membrane is a membrane that allow certain molecules or ions to pass through by diffusion.
Diffusion is the movement of molecules from a region of higher concentration to a region of lower concentration until equilibrium is attained. A special form of diffusion known as osmosis transports water molecules across a semi-permeable membrane.
Osmosis is the movement of water molecules from a region lower solute concentration (high water molecules concentration) to a region of higher solute concentration (low water molecules concentration) until equilibrium is attained.
From the above definitions and the given data;
Glucose concentration is higher in solution outside the sac, thus, glucose molecules will move into the sac.
Water molecules are higher in the sac as a result of the lower concentration of solutes, therefore, water molecules will move out of the sac into the solution outside.
Since the sac is impermeable to albumin, it does not move.
NaCl concentration is lower in the sac, therefore, it will move ro the solution outside into the sac.
Glucose will move into the sac, water will move out of the sac, albumin will neither move in nor out, and NaCl will move into the sac.
The molecules of each of the substances will move by diffusion from the region of higher concentration to the region of lower concentration of each substance as long as there is a permeable membrane. Water, on the other hand, will move by osmosis from the region of high to low water potential through a permeable membrane. Regions with higher concentrations of substances usually have low water potentials and vice versa.Thus, both glucose and NaCl molecules will diffuse from the solution into the sac, and water molecules will move from the sac into the surrounding solution. Since the sac is not permeable to albumin, then the movement in or out is inhibited.
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One of the many remarkable enzymes in the human body is carbonic anhydrase, which catalyzes the interconversion of carbon dioxide and water with bicarbonate ion and protons. If it were not for this enzyme, the body could not rid itself rapidly enough of the CO2 accumulated by cell metabolism. The enzyme catalyzes the dehydration (release to air) of up to 107 CO2 molecules per second. Which components of this description correspond to the terms enzyme, substrate, and turnover number?
Answer:
Enzyme is carbonic anhydrase
Substrate is [tex]CO_2[/tex]
Turnover number is [tex]10^{7}[/tex]
Explanation:
An enzyme is used by a living organism as a catalyst to perform a specific biochemical reaction.
A substrate is a molecule upon which an enzyme acts.
Turnover number refers to the number of substrate molecules transformed by a single enzyme molecule per minute. Here, the enzyme is the rate-limiting factor.
Here,
Enzyme is carbonic anhydrase
Substrate is [tex]CO_2[/tex]
Turnover number is [tex]10^{7}[/tex]
4-Nitrophenol, NO2C6H4OH (pKa 7.15), is only slightly soluble in water, but its sodium salt, NO2C6H4O-Na+, is quite soluble in water. Describe the solubility of 4-nitrophenol in solutions of sodium hydroxide, sodium bicarbonate (NaHCO3), and sodium carbonate (Na2CO3). The pKa values for the conjugate acids of sodium hydroxide, sodium bicarbonate (NaHCO3), and sodium carbonate (Na2CO3) are 15.7, 6.36, and 10.33, respectively. Aqueous NaOH: _________ Aqueous NaHCO3: _________ Aqueous Na2CO3: _________
Answer:
Aqueous NaOH: soluble
Aqueous NaHCO₃: insoluble
Aqueous Na₂CO₃: soluble
Explanation:
The organic acid is insoluble. Its salt (ionic) is soluble.
The important principle is:
If you have two acids in a flask, the stronger acid (smaller pKₐ) will protonate the weaker one. The stronger acid will become ionic and therefore more soluble.
1. In NaOH
Let's write the formula for 4-nitrobenzoic acid as HA.
The equation for the reaction is
HA + OH⁻ ⇌ A⁻ + H₂O
pKₐ: 7.15 15.7
HA is the stronger acid. It will protonate the hydroxide ion and be converted to the soluble 4-nitrobenzoate ion.
4-Nitrophenol is soluble in NaOH.
2. In NaHCO₃
HA + HCO₃⁻ ⇌ A⁻ + H₂CO₃
pKₐ: 7.15 6.36
HCO₃⁻ is the stronger acid. It will protonate 4-nitrophenol.
4-Nitrobenzoic acid is insoluble in NaHCO₃.
3. In Na₂CO₃
HA + CO₃²⁻ ⇌ A⁻ + H₂CO₃
pKₐ: 7.15 10.33
HA is the stronger acid. It will protonate the carbonate ion.
4-Nitrophenol is soluble in Na₂CO₃.
A chemistry student is given of a clear aqueous solution at . He is told an unknown amount of a certain compound is dissolved in the solution. The student allows the solution to cool to . At that point, the student sees that a precipitate has formed. He pours off the remaining liquid solution, throws away the precipitates, and evaporates the water from the remaining liquid solution under vacuum. More precipitate forms. The student washes, dries and weighs the additional precipitate. It weighs 50,0 g.
Using only the information above, can you calculate the solubility of X in water at 16. C. If you said yes, calculate it.
Answer:
Solubility cannot be calculated.
Explanation:
To calculate the solubility of X it is necessary to know the value of the mass of the solute (X) that can be dissolved in 100 g of water.
[tex]Solubility = \frac{Solute mass}{100 grams of water}[/tex]
Taking into account that we do not know the value of the mass of the solution, therefore the value of the solubility of the compound cannot be determined.
what is the correct ionic equation, including all coefficients, charges, and phases for the following sets of reactants? Assume that the contribution of protons from H2SO4 is near 100%.
Ba(OH)2(aq)+H2SO4(aq) —>
help, I have no clue
Answer:
Ba(OH)2(aq)+H2SO4(aq) gives us 2BaH+H2O
Explanation:
3.01 × 1023 molecules H2O
Answer:
0.5 mole
Explanation:
The question isn't even clear
But I'm guessing you want to ask the number of moles
n= Number of molecules/ Avogadros number
n= 1/2
In the compound Fe2O3, iron's oxidation number is +3, and oxygen's oxidation
number is
Answer here
Answer: The oxygen's oxidation number is -2.
Explanation:
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
In [tex]Fe_2O_3[/tex], Fe is having an oxidation state of +3 called as cation and oxygen is an anion with oxidation state of -2. Thus they combine and their oxidation states are exchanged and written in simplest whole number ratios to give neutral [tex]Fe_2O_3[/tex]
The cations and anions being oppositely charged attract each other through strong coloumbic forces and form an ionic bond.
The wolf gets enegry from____
The rabbit gets energy from____
The plant gets energy from___
The mushoom gets energy from___
Answer:
The wolf gets energy from other Animals through Cellular respiration. it's a carnivore
The rabbit gets energy from Carbohydrates,Fats.... obtained through different sources. A common example is the grass. It's an herbivore
The plant gets energy from the sun during photosynthesis. It's Autotrophic.
The mushroom gets energy from the decomposition of other organic matter. It's heterotrophic.
Explanation:
In a food chain; The Wolf eats the rabbit, when the Wolf dies, decomposers such as mushrooms breaks down its body returning it to the soil, where it provides nutrients for plants
8) What is the molarity (M) of an aqueous solution containing 22.5 g of sucrose (C12H22011) in 35.5 mL of solution?
A) 3.52 M
B) 1.85 x 10-2M
C) 0.104 M
D) 0.0657 M
E) 1.85 M
Answer:
E) 1.85 M
Explanation:
M(C12H22O11) = 342.3 g/mol
22.5 g * 1mol/342.3 g = 0.0657 mol
35.5 mL = 0.0355 L
Molarity = mol solute/L solution = 0.0657 mol/0.0355L =1.85 mol/L = 1.85 M
The molarity of the aqueous solution is 1.85 M. The correct option is E) 1.85 M
From the question,
We are to determine the molarity (that is, concentration) of the given sucrose solution
First, we will determine the number of moles present in the given mass of sucrose
Mass of sucrose = 22.5 g
Using the formula
[tex]Number\ of\ moles = \frac{Mass}{Molar\ mass}[/tex]
Molar mass of sucrose = 342.2965 g/mol
∴ Number of moles of sucrose present = [tex]\frac{22.5}{342.2965}[/tex]
Number of moles of sucrose present = 0.0657325 moles
Now, for the molarity (concentration) of the sucrose solution
From the formula
Number of moles = Concentration × Volume
Then,
[tex]Concentration = \frac{Number\ of\ moles}{Volume}[/tex]
From the question,
Volume = 35.5 mL = 0.0355 L
∴ [tex]Concentration = \frac{0.0657325}{0.0355}[/tex]
Concentration = 1.85 M
Hence, the molarity of the aqueous solution is 1.85 M. The correct option is E) 1.85 M
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ch3-ch2-ch-ch(cl)-ch=o IUPAC name
Answer:
2-chloropentanal
Answer:
2-chloropentanal
Explanation:
ch3-ch2-ch-ch(cl)-ch=o IUPAC name
H H H H
H - C - C - C - C - C = O
H H H Cl
So as can be seen 2 as the Chlorine is on the second carbon.
Chloro because of the chlorine.
Pent because there's 5 carbon
al because there's an aldehydes
Aldehyde = −CHO
2-chloropentanal
What is the conjugate acid in the following equation hbr + H2O yields h30 positive + BR negative
Answer:
HBr + H2O = H3O+ + Br-
So our conjugate acid is the H3O+ to H2O
Explanation:
A conjugate acid of a base results when the base accepts a proton.
Consider ammonia reacting with water to form an equilibrium with ammonium ions and hydroxide ions:
NH3 (aq) + H2O (l) ⇌ NH4+ (aq) + OH- (aq)
Ammonium, NH4+, acts as a conjugate acid to ammonia, NH3.
Give the IUPAC name for the following structure
Answer:
6-metyl-2-heptyne
Explanation:
C-C-C-C-C-C-C hept
2
C-C≡C-C-C-C-C 2-heptyne
C
| 6
C-C≡C-C-C-C-C
6-metyl-2-heptyne
The IUPAC name for the above structure is 6 methyl, hept-2-yne.
What is IUPAC?IUPAC stands for international Union of pure and applied chemistry. It is the body in charge of naming organic chemical compounds.
The naming is is based on a molecule's longest chain of carbons connected by single/double/triple bonds, whether in a continuous chain or in a ring etc.
According to this question, a structure is given. The following applies;
The compound has a triple bond located on the second carbon, hence, belongs to alkyne group. It has seven carbon atoms, hence, is heptyne. The methyl group is on the sixth carbon.Learn more about IUPAC at: https://brainly.com/question/33646537
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Nitroglycerin, an explosive, decomposes according to the following equation 4C3H5(NO3)3(s) → 12CO2(g) + 10H2O(g) + 6N2(g) + O2(g) Calculate the total volume of gases produced when collected at 1.45 atm, and 18.0°C from 2.70 × 102 g of nitroglycerin.
Answer:
6.65dm³
Explanation:
Equation of reaction,
4C3H5(NO3)3(s) → 12CO2(g) + 10H2O(g) + 6N2(g) + O2(g)
From the equation of reaction, 4 moles of Nitroglycerin gave 29 moles of various gases.
Molar mass of nitroglycerin C₃H₅(NO₃)₃ = 908g
Since all the product of the reaction are in gaseous phase, let's assume that law of conservation of matter is held hence there's no loss in mass.
908g of C₃H₅(NO₃)₃ = 908g of products
2.70×10²g of C₃H₅(NO₃)₃ = 2.70×10²g of products
Number of moles = mass / molar mass
Molar mass of C₃H₅(NO₃)₃ = 908g/mol
Number of moles = 2.70×10² / 908
Number of moles = 0.297 moles
But 1 mole = 22.4dm³
0.297mole = x dm³
x = (0.297 × 22.4) / 1
x = 6.65dm³
The volume of gas that'll be produced when 2.70×10²g of C₃H₅(NO₃)₃ would be 6.65dm³
how many molecules (not moles) of NH3 are produced from 5.25x10^-4 g of H2?
due in a few, please help. will mark as brainliest
Answer:
not 100% but i think its 1.57x10^20
Explanation:
5.25x10^-4g / 2.016g
2.60x10^-4 x 6.022x10^23= 1.56x10^20 molecules
Find the age ttt of a sample, if the total mass of carbon in the sample is mcmcm_c, the activity of the sample is AAA, the current ratio of the mass of 14 6C 614C to the total mass of carbon in the atmosphere is rrr, and the decay constant of 14 6C 614C is λλlambda. Assume that, at any time, 14 6C 614C is a negligible fraction of the total mass of carbon and that the measured activity of the sample is purely due to 14 6C 614C. Also assume that the ratio of mass of 14 6C 614C to total carbon mass in the atmosphere (the source of the carbon in the sample) is the same at present and on the day when the number of 14 6C 614C atoms in the sample was set. Express your answer in terms of the mass mamam_a of a 14 6C 614C atom, mcmcm_c, AAA, rrr, and λλlambda. View Available Hint(s)
Answer:
Explanation:
An artifact is found in a desert cave. The anthropologists who found this artifact would like to know its age. They find that the present activity of the artifact is 9.25 decays/s and that the mass of carbon in the artifact is 0.100 kg. To find the age of the artifact, they will need to use the following constants:
r=1.2
The activity of carbon 14 is
[tex]A=A_0e^{\lambda t}[/tex]
where,
[tex]A_0[/tex] is the initial activity of the compound
Solve for t
[tex]-\lambda t=In\frac{A}{A_0}[/tex]
[tex]t=-\frac{1}{\lambda} In(\frac{A}{A_0} )[/tex]
[tex]=-\frac{1}{\lambda} In(\frac{A}{\lambda r(\frac{m_c}{m_a} )} )[/tex]
since,
[tex]A_0=\lambda r(\frac{m_c}{m_a} )[/tex]
[tex]=-\frac{1}{\lambda} In(\frac{A\ m_a}{\lambda r m_c} )[/tex]
Now, the age of the artifact is
[tex]=-\frac{1}{\lambda} In(\frac{A\ m_a}{\lambda r m_c} )[/tex]
[tex]=-\frac{1}{1.21\times 10^{-4}} In(\frac{(9.25)(2.32\times 10^{-26}}{1.21\times 10^{-4}(\frac{1}{3.15569\times10^7} )(1.2\times 10^{-12})(0.100)}} )\\\\=6303.4 \ years[/tex]
to two significant figure = 6300 years
What is cell culturing?
a technique that uses specific antibodies to visualize features of cells
a technique that visualizes how specific genes are used within a cell
a technique in which cells are purposefully grown under specific conditions
an imaging technology used to study features smaller than the human eye can see
Answer:
a technique in which cells are purposefully grown under specific conditions
Explanation:
Answer:
its c
Explanation:
correct edge2020
tertbutylamine and ammonia. Which is more basic
Answer:
ammonia
Explanation:
what would happen if you place two positive charges next to each other and let go. would they attract, stay still, or they would repel
Answer:
they would repel
Explanation:
unlike charges attract while like ones repel.
A laser is used in eye surgery to weld a detached retina back into place. The wavelength of the laser beam is 503 nm, while the power is 1.4 W. During surgery, the laser beam is turned on for 0.070 s. During this time, how many photons are emitted by the laser?
Answer:
Number of proton emmitted by laser=[tex]2.48*10^17proton[/tex]
Explanation:
Energy is the ability to cause change; power is directly proportional to energy and its the rate energy is utilized.
Power=energy/time.
First we need to calculate the total energy used which is equal to the total power utilized.
E(total)= P( total) = 1.4W × 0.070 s =[tex]0.098J[/tex]
CHECK THE ATTACHMENT FOR THE REMAINING DETAILED CALCULATION
Arrange the measurements from least to greatest
Answer: 1.8 micrograms, 1.8 milligrams, 1.8 grams, 1.8 kilograms
Explanation:
Indicate whether each of the following indicates that a physical or chemical change has taken place when a piece of magnesium metal is studied: (a) Can be cut into tiny pieces (b) Fizzling occurs when placed water (c) Light is emitted when burned (d) Turns to ash
Answer:
a) Can be cut into tiny pieces - Physical Change
b) Fizzling occurs when placed water -Chemical Change
c) Light is emitted when burned -Chemical Change
d) Turns to ash -Chemical Change
Explanation:
.Draw the born-Haber lattice energy cycle for sodium chloride. Explain the concept of resonance using the nitrate ion structure.
Answer:
Born-Haber cycle is consist on four to five steps. 1: ionization energy 2: electron affinity 3: dissociation energy 4: sublimation energy and last is Hess law.Nitrate ion have 3 localized sigma bonds and 1 delocalized pie bond according to the resonance structure.Explanation:
Step 1: NaCl(s) → Na(s) + 1/2 Cl2(g) ΔHf (ionization energy) in this step energy is required to change the phase of the compound
Step 2: Na(s) + 1/2 Cl2(g) → Na(g) + 1/2 Cl2(g) ΔHa (elements needed to be in gaseous state for born-haber cycle so metal changes from solid to gas state by changing the enthalpy.
Step 3: Na(g) + 1/2 Cl2(g) → Na(g) + Cl (g) 1/2ΔHd
Step 4: Na(g) + Cl(g) → Na⁺(g) + Cl⁻(g) IE+EA ( in this step both ionization energy and electron affinity was involved because in metal (Na) electron is added which needs the energy and this energy draw from the step 3 and Chlorine require releasing electron to be in ionic state so when electron leaves the orbit energy releases.
Step 5: final step is Hess Law which is the combination of all the steps which step 4 again go back to step 5 and this cycle continues by repeating same steps Na⁺(g) + Cl⁻(g)→NaCl(s)
at this step heat of formation is calculated
Heat of formation= atomization energy+ dissociation energy+ sum of ionization energies + sum of electron affinity + lattice energy.
2: if we look at the electron configuration of the nitrogen it has 5 electrons in its outermost shell which indicates it can make 5 bonds 4 bonds and 1 lone pair usually and Oxygen has 6 electrons in its outermost shell. So nitrate ion have the total number of 24 electrons including the 1 electron which shows on the compound.
So when they make nitrate ion NO₃⁻¹ it shows that nitrate has 3 resonance structures. Nitrogen's three sigma bonds are attached to oxygen and fourth one make 1 pie bond which can rotate, delocalized and change its position anytime from one Oxygen atom to other oxygen atom.
Which of the compounds below are amines?
1. H4C-NH-CH3
2. H3C-NH-C-CH3
H2C-CH3
1 +
H3C-CH2-N-CH3
CH3
N
3. H
4.
Answer:
1. H4C-NH-CH3
2. H3C-NH-C-CH3
H2C-CH3
1 +
H3C-CH2-N-CH3
CH3
N
3. H
4.
.
.
.
.
.
.
