Answer:
A photon is absorbed by the atom.
More energy is emitted or absorbed for case 2
Explanation:
According to the Bohr model of the atom, electrons occur in energy levels. The energy of each level is fixed. However, electrons can absorb photons and move from a lower to higher energy level or emit photons and move from a higher to a lower energy level.
In each case, the energy absorbed or emitted is equal to the difference in energy between the two energy levels.
Since energy level 3 is much higher than energy level 2, the electron absorbs more energy in moving from energy level 1 to energy level 3 than it absorbs when moving from energy level 1 to energy level 2.
3. 3. A 90.-mL sample of juice was titrated with the I2(aq) solution described above using a sb buret. The initial reading of the sb buret was 58.3 mL. When the endpoint was reached, the reading on the sb buret was 26.9 mL. How many mg of Vitamin C were in the juice sample
Answer:
2765mg of Vitamin C assuming the concentration of I2 = 0.500M
Explanation:
Iodine, I2, reacts with vitamin C in a ratio of 1:1 (The moles of I2 added = Moles of Vitamin C in the sample). To solve this question we must find the difference in volume from the initial reading to the endpoint reading. Now, ASSUMING the molar concentration of the I2(aq) solution is 0.500M we can find the moles of I2 = Moles of Vitamin C. With its molar mass -176.12g/mol- we can find its mass:
Moles I2:
Volume = 58.3mL - 26.9mL = 31.4mL = 0.0314L * (0.500mol / L) = 0.0157 moles I2 = Moles Vitamin C
Mass Vitamin C:
0.0157 moles * (176.12g/mol) = 2.765g of Vitamin C * (1000mg/1g) =
2765mg of Vitamin C assuming the concentration of I2 = 0.500M
2.67 Determine the density (g/mL) for each of the following:
a. A 20.0-mL sample of a salt solution has a mass of 24.0 g.
The density (g/mL) for a 20.0-mL sample of a salt solution has a mass of 24.0 g is 1.2 g/ml.
What is density?Density is the mass per unit volume. Density is a scalar quantity. It is denoted by d and the symbol for density is given as rho, a Greek symbol. Density is calculated as mass divided by volume.
Mass is the quantity of matter in a physical body. The product of the molar mass of the compound and the moles of the substance are defined as mass.
Volume is the space occupied by a three-dimensional object. Volume is calculated by dividing mass by density.
Given, the 20.0-mL sample of a salt solution, which is the volume.
The mass of the solution is 24.0 g
To calculate the density
mass/volume
24.0 / 20.0 = 1.2 g/ml
Thus, the density of the given salt solution is 1.2 g/ml.
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Question 1 of 10
What happens when a solid becomes a liquid?
Answer:it dissolves and evaporates
Explanation:
What waves are used to send signals because they can travel over very long distances and pass through buildings
Answer:
sound waves for used I think
The oxygen atom of a ketone (such as cyclohexanone) contains 2 lone pairs of electrons. These pairs of electrons most likely reside in what type of orbital
Answer: The given pairs of electrons most likely reside in [tex]sp^{2}[/tex] type of orbital.
Explanation:
As it is given that two lone pair of electrons are present on the oxygen atom of ketone (such as cyclohexanone).
Also, there will be one bond pair between carbon and oxygen atom.
Hence, total electrons present in the domain are as follows.
2 lone pairs + 1 bon pair of electron = 3 electron domains
This means that there will be [tex]sp^{2}[/tex] type of orbital present.
Thus, we can conclude that given pairs of electrons most likely reside in [tex]sp^{2}[/tex] type of orbital.
Whether or not the process is observed in nature, which of the following could account for the transformation of phosphorus-28 to silicon-28?
a. beta decay.
b. eletron capture
c. positron emission
d. alpha decay
Answer:
positron emission
Explanation:
Positron emission,involves the decrease in the nuclear positive charge thus the atomic number of the daughter nucleus decreases by one unit compared to that of the parent nucleus while the mass number of the daughter nucleus remains the same as that of the parent nucleus.
Thus, when phosphorus-28 is transformed into to silicon-28, a positron emission has taken place because the mass number of the daughter nucleus remained the same while the atomic number of the daughter nucleus was decreased by one unit.
12.0: A
Mention three body fluids that are alkaline in nature
Draw the predominant product(s) of the following reactions including stereochemistry when it is appropriate. CH3CH2 C C CH3 H2O/H2SO4/HgSO4
Answer:
Draw the predominant product(s) of the following reactions including stereochemistry when it is appropriate.
CH3CH2 C C CH3 H2O/H2SO4/HgSO4
Explanation:
The given compound is: pent-2-yne.
When it reacts with water, in presence of sulphuric acid and mercuric sulphate then a ketone is formed as shown below:
This reaction is an example of nucleophilic attack of water on carbon carbon triple bond.
The general mechanism of the reaction is hsown below:
Pent-2-yne reacts with water and form 3-pentanone.
The reaction is shown below:
Which of the following ions is formed when an acid is dissolved in a solution? (5 points)
H+
O−
OH−
SO42+
Answer:
H +
Explanation:
Acid are those species which donates the H+ ion when dissolved in a solution. In other way acid are those chemical species which donate proton to other species as proton means H+ ion so H+ ions are formed as a result of dissolution ..
For a non-inverting amplifier if R1= ∞ ohm, then the gain of the amplifier is:
(a) Zero
(b) -1
(c) +1
(d) Infinite
Answer:
its d
Explanation:
What is the speed of a wave with a frequency of 2 Hz and a wavelength of 87m (subject is science) pls answer fast
Answer:
43.5
Explanation:
Hope that helps
Round 5578 L to three significant figures.
a. 557 L
b. 558 L
c. 5.58 x 10(3) L
d. 5.58 x 10(-3) L
Answer:
b
Explanation:
The figures of a number that are noteworthy in high accuracy or precision are known as significant figures. They are as follows:
Any digit that isn't zeroAs in 20012 or 64.60007, there are zeros between non-zero numbers.Only use leading zeros when a decimal point is present, such as in 5640.0 or 532.330.If the figure is less than 5, remove it and leave the rest of the number unaffected but if more than 5 add, round it up to 1, and add it to the next figure in the line.From the given information:
To (3) sig. fig: 5578 L = 558 L
Lab 2: paper chromatography of organic dyes
Picture of questions below.
Answer:
The three primary colors used when mixing dyes or paints are red, yellow, and blue. Other colors are often a mixture of these three colors. Try running a chromatography test again with non-primary-color markers, like purple, brown, and orange.
Explanation:
Mixtures that are suitable for separation by chromatography include inks, dyes and colouring agents in food. ... As the solvent soaks up the paper, it carries the mixtures with it. Different components of the mixture will move at different rates. This separates the mixture out.
A solution of KMnO4 has an absorbance of 0.539 when measured in the colorimeter. Determine the concentration of the KMnO4 given the following data for a calibration plot.
Concentration of KMNO4 (M) Absorbance
0.0150 0.081
0.0300 0.159
0.0450 0.260
0.0600 0.334
Answer:
Concentration of unknown solution is 0.0416 M
Explanation:
As we know
Absorbance is equal to the product of molar absorptivity of KMnO4 m, path length and concentration
From the given set of graphical data, it is clear that the absorbance vs concentration is a straight line.
From the graph, we can obtain-
Y = 5.73 X – 0.0065
Absorbance = 0.232
0.232 = 5.73 X – 0.0065
X = 0.0416
Concentration of unknown solution is 0.0416 M
According to hydrogen’s chemical properties, it belongs in the same group as:
1. alkali metals
2. alkaline earth metals
3 .halogens
4. both a and c
---
Select the following group of elements that contains elements with similar chemical properties
A.
N, As, Bi
B.
Rb, Sn, In
C.
Li, Mg, Ga
D.
W, Tc, Fe
---
Propose two steps that could be taken to reduce the vulnerability of the US to hurricanes. Explain why you think those would be effective in saving lives and property.
This is not just about planning and design of buildings and towns/cities, even though those are very important. You could write about the role of research in science and technology and their contributions to emergency preparedness.
You must write at least one paragraph (roughly 150 words).
Answer:
Sensors and evacuation planning.
Explanation:
Sensors that provides information about hurricane and evacuation planning are the two steps that can reduce the vulnerability of the United States to hurricanes. Sensors provides information about hurricane so we can prepare ourselves about it and the evacuation plan helps in order to quick displacement of people from the hurricane area so these two steps can reduce the vulnerability of the US to hurricanes.
When an electron moves up to higher energy levels, the atom Choose... a photon of light whereas the atom Choose... a photon of light when an electron drops to a lower energy level. The photons emitted from an atom appear as
Answer:
Explanation:
When an electron moves from a lower energy level to a higher energy level, energy is absorbed by the atom. When an electron moves from a higher to a lower energy level, energy is released and photon is emitted.
this emitted photon is depicted as a small wave-packet being expelled by the atom in a well-defined direction.
Helllppp asapppp
Which of the following is matter?
O A. Light
O
B. Sound
O C. Atoms
O D. Radio waves
张
ci Metal displaces 50cm of water
when completely immersed in water if the mos
of the metal is 35.0q, calculate its
density
Answer:
0.70 g/cm³
Explanation:
Step 1: Given data
Volume of water displaced by the metal (V): 50 cm³ (this is equal to the volume of the metal)Mass of the metal (m): 35.0 gStep 2: Calculate the density (ρ) of the metal
Density is an intrinsic property of matter. It is equal to the mass of the metal divided by its volume.
ρ = m/V
ρ = 35.0 g/50 cm³ = 0.70 g/cm³
To determine the enthalpy and entropy of dissolving a compound, you need to measure the Ksp at multiple _______. Then, plot ln(Ksp) vs. ______. The slope of the plotted line relates to the _______ of dissolving and the intercept of the plotted line relates to the ______ of dissolving.
Answer:
To determine the enthalpy and entropy of dissolving a compound, you need to measure the Ksp at multiple temperatures. Then, plot ln(Ksp) vs. 1/T. The slope of the plotted line relates to the enthalpy (ΔH) of dissolving and the intercept of the plotted line relates to the entropy (ΔS) of dissolving.
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us use the thermodynamic definition of the Gibbs free energy and its relationship with Ksp as follows:
[tex]\Delta G=-RTln(Ksp)\\\\\Delta G=\Delta H-T\Delta S[/tex]
Thus, by combining them, we obtain:
[tex]-RTln(Ksp)=\Delta H-T\Delta S\\\\ln(Ksp)=-\frac{\Delta H}{RT} +\frac{T\Delta S}{RT} \\\\ln(Ksp)=-\frac{\Delta H}{RT} +\frac{\Delta S}{R}[/tex]
Which is related to the general line equation:
[tex]y=mx+b[/tex]
Whereas:
[tex]y=ln(Ksp)\\\\m=-\frac{\Delta H}{R} \\\\x=\frac{1}{T} \\\\b=\frac{\Delta S}{R}[/tex]
It means that we answer to the blanks as follows:
To determine the enthalpy and entropy of dissolving a compound, you need to measure the Ksp at multiple temperatures. Then, plot ln(Ksp) vs. 1/T. The slope of the plotted line relates to the enthalpy (ΔH) of dissolving and the intercept of the plotted line relates to the entropy (ΔS) of dissolving.
Regards!
Write the step-by-step mechanism for the following reactions showing, initiation, propogation and atleast one termination rections.
a. The light-initiated reaction of cyclohexane with chlorine to give chlorocyclohexane
b. The reaction between cyclobutane and bromine to give bromocyclobutane
Answer:
See explanation and image attached.
Explanation:
A free radical reaction is a reaction that involves species having an odd number of electrons.
The initiation step involves the formation of the odd electron species. The propagation steps produce more odd electron species while the termination steps eliminate the odd electron species.
The halogenation of alkanes occurs by free radical mechanism. The initiation, propagation and termination steps for the free radical chlorination of cyclohexane and cyclobutane is shown in the image attached.
calculate the relative molecular
mass of Zn (NO3)2
Answer:
Okyu
Explanation:
Mass of Zn = 65
(NO3)2 = 124
[tex]65 + (14 + 16 \times 2) \times 2 \\ 65 + 124 \\ = 184g mol[/tex]
Explanation:
Mass of Zn = 65
(NO3)2 = 124
\begin{gathered}65 + (14 + 16 \times 2) \times 2 \\ 65 + 124 \\ = 184g mol\end{gathered}
65+(14+16×2)×2
65+124
=184gmol
2.
A solution contains 50 g of KCl per 100 g of water at
90°C. Is the solution unsaturated, saturated or
supersaturated?
unsaturated, saturated or supersaturated?
4. After reaching the final titration endpoint the solution will be cloudy white. As time goes on the solution will turn back to a cloudy dark purple color. Why does this occur if you have already reached the endpoint
Answer: hello some part of your question is missing below is the missing part
In an experiment to determine the % of ascorbic acid in Vitamin C Tablets by Titration with Potassium Bromate,
answer:
Oxidation half reaction of Vitamin C
Explanation:
The solution will turn cloudy dark purple even after reaching endpoint when allowed to settle with time. because of the Oxidation half reaction of Vitamin C. also during the Titration process few drops of starch solution will be added to help determine the endpoint of the experiment .
To prepare a sample in a capillary tube for a melting point determination, gently tap the tube into the sample with the ___________ end of the tube down. Continue tapping until the sample. _____________ Then, with the __________ end of the tube down, tap the sample down slowly or __________ to move the sample down faster. Finally, make sure that you can see ___________ in the magnifier when placed in the melting point apparatus before turning on the heat.
Answer: Hello I was able to find the missing options related to your question online but I couldn't attach them hence I just used them to provide the relevant solution
answer:
Open Is a couple of millimeters highclosed Drop tube into a longer tube sample clearlyExplanation:
OPEN end of the tube down. Continue tapping until the sample. Is a couple of mm high Then, with the Closed end of the tube down, tap the sample down slowly or drop tube into a longer/larger tube to move the sample down faster. Finally, make sure that you can see sample clearly in the magnifier when placed in the melting point apparatus before turning on the heat.
once water reach its boiling point what does you notice about its temperature??
0.159 mol 2.25 M = A L of HCI
Answer:
hmmm?what?
Explanation:
ayusin mo flece:>
Which of these is a model that
represents valence electrons in
an atom as dots around the
element's chemical symbol?
What are the lengths of the diagonals of the kite?
The answer ( 13 and 8 )
x²=5²+12²
x²=25+144
x²=169
x=13
x²=5²+6²
x²=25+36
x²=61
x=7.8
x=8
Classify each compound as ionic or molecular.
a. ZnCl2
b. MgS
c. CH4
Answer:
ZnCl2=ionic
MgS=ionic
CH4=molecular
Explanation:
ZnCl₂=ionic, MgS=ionic and CH₄=molecular compounds.
Thus, Ions with opposing charges that are kept together by electrostatic forces make up ionic compounds. Typically, a metal and a nonmetal combine to make them.
Atoms share electrons through covalent bonds to form molecular compounds.
When atoms of various elements share electrons through covalent bonds, molecules are created, also known as covalent compounds. These compounds consist of molecules made up of joined atoms, and the shared electrons strengthen the bonds between the atoms.
Thus, ZnCl₂=ionic, MgS=ionic and CH₄=molecular compounds.
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