Complete Question
Determine the end (final) value of n in a hydrogen atom transition, if the electron starts in n=4 and the atom emits a photon of light with a wavelength of 486 nm. Group of answer choices
Answer:
[tex]n=2[/tex]
Explanation:
From the question we are told that:
Wavelength [tex]\lambda=486nm=>486*10^{-9}[/tex]
Generally the equation for Atom Transition is mathematically given by
[tex]\frac{1}{\lambda}=R_{\infty }(\frac{1}{n_1^2}-\frac{1}{n_2^2})[/tex]
Where
Rydberg constant [tex]R_{\infty}=1.097*10^7[/tex]
Therefore
[tex]\frac{1}{486*10^{-9}}=1.097*10^7*(\frac{1}{n_1^2}-\frac{1}{4^2})[/tex]
[tex](\frac{1}{n_1^2}-\frac{1}{4^2})=\frac{1}{486*10^{-9}*1.097*10^7}[/tex]
[tex]n_1^2=3.98[/tex]
[tex]n=1.99[/tex]
[tex]n=2[/tex]
Using the Rydberg formula, the final state of the electron is n=2.
Using the Rydberg formula;
1/λ = R(1/nf^2 - 1/ni^2)
Where;
λ = wavelength
nf = final state
ni = initial state
R = Rydberg constant
When λ = 486 × 10^-9 m and ni = 4, R = 1.097 × 10^7 m-1
1/486 × 10^-9 = 1.097 × 10^7(1/nf^2 - 1/4^2)
0.188 = 1/nf^2 - 0.0625
1/nf^2 = 0.188 + 0.0625
nf = 2
Missing parts;
Determine the end (final) value of n in the hydrogen atom transition, if electron starts in n-4 and the atom emits a photon of light with a wavelength of 486.
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Construction of battery cells
Answer:
These batteries are constructed of several single cells connected in series each cell produces approximately 2.1 volts. ... A battery cell consists of two lead plates a positive plate covered with a paste of lead dioxide and a negative made of sponge lead, with an insulating material (separator) in between.
A compound that contains only carbon, hydrogen, and oxygen is 58.8% C and 9.87% H by mass. What is the empirical formula of this substance
Answer: The empirical formula of the compound becomes [tex]C_5H_{10}O_2[/tex]
Explanation:
The empirical formula is the chemical formula of the simplest ratio of the number of atoms of each element present in a compound.
Let the mass of the compound be 100 g
Given values:
% of C = 58.8%
% of H = 9.87%
% of O = [100 - 58.8 - 9.87] = 31.33%
Mass of C = 58.8 g
Mass of H = 9.87 g
Mass of O = 31.33 g
The number of moles is defined as the ratio of the mass of a substance to its molar mass. The equation used is:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)
To formulate the empirical formula, we need to follow some steps:
Step 1: Converting the given masses into moles.Molar mass of C = 12 g/mol
Molar mass of H = 1 g/mol
Molar mass of O = 16 g/mol
Putting values in equation 1, we get:
[tex]\text{Moles of C}=\frac{58.8g}{12g/mol}=4.9 mol[/tex]
[tex]\text{Moles of H}=\frac{9.87g}{1g/mol}=9.87 mol[/tex]
[tex]\text{Moles of O}=\frac{31.33g}{16g/mol}=1.96mol[/tex]
Step 2: Calculating the mole ratio of the given elements.Calculating the mole fraction of each element by dividing the calculated moles by the least calculated number of moles that is 1.96 moles
[tex]\text{Mole fraction of C}=\frac{4.9}{1.96}=2.5[/tex]
[tex]\text{Mole fraction of H}=\frac{9.87}{1.96}=5.03\approx 5[/tex]
[tex]\text{Mole fraction of O}=\frac{1.96}{1.96}=1[/tex]
Converting the mole fraction into whole numbers by multiplying them with 2.
[tex]\text{Mole fraction of C}=2.5\times 2=5[/tex]
[tex]\text{Mole fraction of H}=5\times 2=10[/tex]
[tex]\text{Mole fraction of O}=1\times 2=2[/tex]
Step 3: Taking the mole ratio as their subscripts.The ratio of C : H : O = 5 : 10 : 2
Hence, the empirical formula of the compound becomes [tex]C_5H_{10}O_2[/tex]
The empirical formula of the substance is[tex]C_5H_{10}O_2[/tex].
Explanation:
Given:
A compound made up of 58.8% of carbon, 9.87% hydrogen, and oxygen.
To find:
The empirical formula of this substance.
Solution
The percentage of carbon in a given substance by mass = 58.8%
The percentage of hydrogen in a given substance by mass = 9.87%
The percentage of oxygen in a given substance by mass :
[tex]= 100\%-58.8\%- 9.87\%=31.33\%[/tex]
Consider 100 grams of a substance.
In 100 grams of substance:
The mass of carbon =58.8% of 100 g = 58.8 g
The mass of hydrogen = 9.87% of 100 g = 9.87 g
The mass of oxygen = 31.33% of 100 g= 31.33 g
The moles of carbon [tex]=\frac{58.8 g}{12.0107 g/mol}=4.90 mol[/tex]
The moles of hydrogen[tex]=\frac{9.87g}{1.00784g/mol}=9.79 mol[/tex]
The moles of oxygen[tex]=\frac{31.33g}{15.999g/mol}=1.96 mol[/tex]
let the empirical formula of the substance = [tex]C_xH_yO_z[/tex]
The value of subscript x:
[tex]=\frac{4.90 mol}{1.96 mol}=2.5[/tex]
The value of subscript y:
[tex]=\frac{9.79mol}{1.96 mol}=5[/tex]
The value of subscript z:
[tex]=\frac{1.96mol}{1.96 mol}=1[/tex]
The empirical formula of a substance :
[tex]C_{2.5}H_5O_1=C_{\frac{25}{10}}H_5O_1=C_{25}H_{50}O_{10}[/tex]
Reducing to the lowest whole numbers:
[tex]C_{25}H_{50}O_{10}=C_5H_{10}O_2[/tex]
The empirical formula of the substance is [tex]C_5H_{10}O_2[/tex].
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You are stowing items and come across an aerosol bottle of hairspray. What should you do? Please choose all that apply
Answer:stow the hairspray
Explanation:
How many molecules of C 2H 5Br will be present if you had 4.52 g of this compound?
Evaporation is commonly used to concentrate dissolved solids in a liquid feed stream and produce pure water vapor.
a. True
b. False
Answer:
True
Explanation:
Evaporation is the process by which a substance changes its state from liquid to gas. evaporation occurs at all temperatures but it's rate increases as temperature increases.
Pure water vapour can be produced by evaporation.
As the liquids are removed, the solids present in solution becomes more concentrated.
Why ethanol is used in pectin extraction
Explanation:
is responsible for interrupting the interaction between pectins and solvent molecules
When sodium chloride, NaCl , dissolves in water, the solution contains ___________________ in addition to the water solvent. The partial charges in water help dissolve the compound as the hydrogen end of water is attracted to the ____________ and the oxygen end is attracted to the _______________
Answer:
sodium ions and chloride ions
chloride ion
sodium ion
Explanation:
Ionic substances are composed of ions. When you dissolve an Ionic substance in water, the ions that compose the substance together with water molecules are present in solution.
Hence, when sodium chloride is dissolved in water, sodium ions and chloride ions are released in solution.
Water has a dipole moment. Hence, the chloride ions are attracted to hydrogen (the positive end of the dipole) while sodium ions are attracted to oxygen (the negative end of the dipole).
This is how the solid is dissolved in water.
When sodium chloride, NaCl , dissolves in water, the solution contains sodium and chloride ions in addition to the water solvent. The partial charges in water help dissolve the compound as the hydrogen end of water is attracted to the chloride ions and the oxygen end is attracted to the sodium ions.
What molecules are soluble in water?Those molecules in which positive ion as well as negative ion is present, will show solubility in water.
Sodium chloride (NaCl) is an ionic compound, which dissociates into sodium ion and chloride ion in the water. As in the water H⁺ ions are present which get attracted towards the chloride ions (Cl⁻) and hydroxide ion (OH⁻ ion) get attracted towards the sodium ions (Na⁺) and show complete dissolution.
Hence correct answers are sodium and chloride ions, chloride ion and sodium ion.
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list four energy resources
Answer:
Nuclear
Solar
Wind
Hydro
Geo-Thermal
Explanation:
Solar energy from the sun.Geothermal energy from heat inside the earth.Wind energyBiomass from plants.hope it helps
stay safe healthy and happy....True/False: Chemical reactions can NOT proceed in the reverse direction
1 or 2 topics or two lessons should be explained in an illustrated childrens book minimum of 10 pages must have 3 or more sentences
Answer:
Yes because same topic are long
100.0 mL of a 0.780 M solution of KBr is diluted to 500.0 mL. What is the new concentration of the solution?
Draw the major product that is obtained when (2S,3S)-2-Bromo-3-phenylbutane is treated with sodium ethoxide.
Answer:
Explanation:
The mechanism of the reaction is shown in the diagram below. From the reaction, when (2S,3S)-2-Bromo-3-phenylbutane undergoes a reaction with sodium ethoxide (ETONa), the E2 elimination reaction is put into place. Here, the H and the leaving group are antiperiplanar to one another and the reaction mechanism proceeds to form an isomeric (E)-2-phenyl-2butane as the major product.
When 2.50 moles of oxygen reacts with excess hydrogen gas how many grams of water is
produced?
2 H2 + O2--> 2 H20
Answer:
90grams
Explanation:
The reaction given in this question is as follows:
2H2 + O2 → 2H20
Based on this equation, 1 mole of oxygen gas (O2) produces 2 moles of water (H2O)
Hence, 2.50moles of oxygen gas will react with excess hydrogen gas to produce (2.5 × 2) = 5.0moles of water.
Using mole = mass/molar mass
Molar mass of water (H2O) = 1(2) + 16
= 18g/mol
5 = mass/18
mass = 18 × 5
mass of H2O = 90grams
Draw a sketch showing what osmotic pressure is. Label on the sketch solute, solvent, hypertonic, hypotonic and semi permeable membrane.
Water has a density of 1.00 g/mL. If you put an object that has a density of 0.79 g/mL into water, it will sink to the bottom.
ANSWER please
True
False
Answer:
False
Explanation:
An object with a density less than the density of water will float.
And an object that is denser than water (more than 1.00g/mL) will sink when placed in water.
¿soy guapo?
si dices que si te doy una galletita
Answer:
Hindi ko po ma gets sinasabi nyu pwedeng pakiayus
Match the following terms to their correct definitions.
ResetHelp
A cell that requires energy to bring about a nonspontaneous redox reaction.
An ion-containing conducting medium used to physically and chemically connect the two half-cells in an electrochemical cell.
A cell that requires energy to bring about a nonspontaneous redox reaction.
To move to drop area press Tab key.
faraday
salt bridge
anode
cathode
voltaic cell
electrolytic cell
Answer:
Electrolytic cell. Salt bridge.
Explanation:
Match the following terms to their correct definitions.
A cell that requires energy to bring about a nonspontaneous redox reaction. Electrolytic cell. In an electrolytic cell, energy is provided from an outer source, such as a battery. An ion-containing conducting medium used to physically and chemically connect the two half-cells in an electrochemical cell. Salt bridge. The salt bridge contains a salt (strong electrolyte) and it is fundamental in a voltaic cell.if a=1/2(a+b)h,express a in terms of A,b and h. pls solve with step by step
Answer:
[tex] a = \frac {2A - bh}{h} [/tex]
Explanation:
Given the following mathematical expression;
A = ½(a + b)h
To make a the subject of formula (express a in terms of A, b and h);
First of all, we would cross-multiply;
2A = (a + b)h
Opening the bracket, we have;
2A = ah + bh
Rearranging the mathematical expression, we have;
ah = 2A - bh
[tex] a = \frac {2A - bh}{h} [/tex]
A beaker is filled to the 500 mL mark with alcohol. What increase in volume (in mL) does the beaker contain when the temperature changes from 5° C to 30° C? (Neglect the expansion of the beaker, evaporation of alcohol and absorption of water vapor by alcohol.) The volume coefficient of expansion γγ for alcohol = 1.12 x 10-4 K-1
Answer:
"1.4 mL" is the appropriate solution.
Explanation:
According to the question,
[tex]v_0=500[/tex][tex]\alpha =1.12\times 10^{-4}[/tex][tex]\Delta \epsilon = 25[/tex]Now,
Increase in volume will be:
⇒ [tex]\Delta V = \alpha\times v_0\times \Delta \epsilon[/tex]
By putting the given values, we get
[tex]=1.12\times 10^{-4}\times 500\times 25[/tex]
[tex]=1.12\times 10^{-4}\times 12500[/tex]
[tex]=1.4 \ mL[/tex]
Part A: Calculate the mass of butane needed to produce 75.6g of carbon dioxide.
Part B: Calculate the mass of water produced when 5.48g of butane reacts with excess oxygen.
Answer:
Multiply the number of moles of butane by its molar mass, 58.12g/mol, to produce the mass of butane. Mass of butane = 18.8g.
Explanation:
Part B:
The mass of water produced when 4.86 g of butane(C4H10) react with excess oxygen is calculated as below
calculate the moles of C4H10 used = mass/molar mass
moles = 4.86g/58 g/mol =0.0838 moles
write a balanced equation for reaction
2 C4H10 + 13 O2 = 8 CO2 + 10 H2O
by use of mole ratio between C4H10 to H2O which is 2:10 the moles of
H20= 0.0838 x10/2 = 0.419 moles of H2O
mass = moles x molar mass
=0.419 molx 18 g/mol = 7.542 grams of water is formed
if salt and sand is mixed with distilled water, what will be the residue? and, what will be the filtrate?
Answer:
Filtration is a technique used as a remedy to separate mixes
Explanation:
If you have a sodium, then you will explore that salt dissolves but the sand is still the same.
If the salt in the resin water solution scanners, the sand remains the residue and passes through the filter paper.
All you have to do now is pleasant the salty water so that the water can evaporate, leaving the salt behind.
g in the following three compounds(1,2,3) arrange their relative reactivity towards the reagent CH3Cl / AlCl3. Justify your order
Answer:
3 > 2> 1
Explanation:
Aromatic compounds undergo electrophilic substitution reaction with several electrophiles.
Some substituted benzenes are more reactive towards electrophilic aromatic substitution than unsubstituted benzene.
Certain groups of substituents increase the ease with which an aromatic compound undergoes aromatic substitution.
If we look at the compounds closely, we will notice that only toluene leads to easy reaction with CH3Cl / AlCl3. Thus is due to the +I inductive effect of -CH3 which stabilizes the negatively charged intermediate produced in the reaction.
Why do gases act more ideal at
lower pressures?
Answer:
Gases act more ideal at lower pressure beacuse the attractive forces between molecules will decrease or become less significant compared to the empty space between them.
Explanation:
Generally, a gas behaves more like an ideal gas at higher temperature and lower pressure as the potential energy due to intermolecular forces becomes less significant compared with the particles "kinetic energy" and the size of the molecules become less significant compared to the empty space between them.
Attractive forces between molecules, decrease the pressure of a reak gas, slowing the molecules and reducing collisions with the walls.The higher the value of a gas, the greater the attraction between molecules and the more easily the gas will compress.
HOPE IT HELPS MUCHanswered by: John Glenly Pillazo Mahusay
Which probing question lies within the scope of physics?
O A.
Are fish in the open ocean
attracted by underwater sounds?
O B.
Does increasing the saltiness of
ocean water affect the speed
of sound in the water?
O C.
What effect does the release of industrial wastewater have on
the acidity of oceans?
D. What is the effect of rising sea temperatures on
ocean currents?
Answer:
answer number C is the correct answer for this
g Calculate the percent yield when you start with 0.50 grams of salicylic acidand end with 0.33 grams of aspirin. The molecular weight of salicylic acid is 138.12 g/mol, and the molecular weight of aspirin is 180.157 g/mol.
Explanation:
hope the picture above helps you to understand:)
What does Gibbs free energy predict?
A. It predicts what the rate of the reaction will be.
B. It predicts how high the activation energy is.
C. It predicts if entropy will increase or decrease.
D. It predicts whether or not a reaction will be spontaneous.
Answer:
It predicts whether or not a reaction will be spontaneous.
Explanation:
The equation;
∆G= ∆H - T∆S enables us to obtain the Gibbs free energy of a chemical process.
The Gibbs free energy value tells us whether a chemical process will be spontaneous or not.
When;
∆G>0 the reaction is not spontaneous
∆G=0 the reaction is at equilibrium
∆G<0 the reaction is spontaneous
Suppose you need to prepare 138.1 mL of a 0.190 M aqueous solution of NaCl. What mass, in grams, of NaCl do you need to use to make the solution
Answer:
Explanation:
· 44 g NaCl Explanation: The problem provides you with the molarity and volume of the target
The answer is rounded to two sig figs, the number of sig figs you have for the molarity of the solution.
The mass of a solute needed to prepare a solution with given volume is find by molarity. The mass of NaCl need to make a 138.1 mL solution of 0.190 M is 1.53 grams.
What is molarity ?Molarity of a solution is a term to express its concentration. Mathematically, it is the ratio of no.of moles of solute to the volume of solution in litres.
Given that, the volume of solution is 138.1 mL. One litre solution is 1000 mL. Hence, 138.1 mL is 0.1381 L. The molarity of the solution is 0.190 M. From these data we can calculate the no.of moles of NaCl as below:
no.of moles = molarity × volume of solution in L
= 0.190 M × 0.1381 L
= 0.0262 moles.
This is the no.of moles required to make the solution.
Molecular mass of NaCl = 58.4 g/mol.
Thus mass of 0.0262 moles of NaCl = 0.0262 mol × 58.4 g/mol
= 1.53 g.
Therefore, the mass of NaCl required is 1.53 g.
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Does a reaction occur when aqueous solutions of copper(II) nitrate and calcium chloride are combined
Answer:
Does a reaction occur when aqueous solutions of copper(II) nitrate and calcium chloride are combined?
Explanation:
The given reaction is an example of a chemical double displacement reaction.
The mutual interchange of the ions takes place.
The balanced chemical equation of the reaction is:
[tex]Cu(NO_3)_2(aq)+CaCl_2(aq) -> Ca(NO_3)_2(aq)+CuCl_2(aq)[/tex]
All the products formed are also highly soluble.
So, all the ions are spectator ions.
Hence, all will cancel with each other and ions remain in the net ionic equation and hence, the reaction does not take place.
All --- is a good conductor of heat
Determine the kinds of intermolecular forces that are present in each element or compound. Part A KrKr Check all that apply. Check all that apply. dispersion forces dipole-dipole forces hydrogen bonding
Answer:
The kinds of intermolecular forces that are present in each element Kr-Kr.
Explanation:
Since Kr is an inert gas and in atomic form only it is highly stable.
So, Kr gas does not form molecules.
Between the atoms of inert gas, there exist London dispersion forces.
Hence, the intermolecular forces that are present between Kr-Kr atoms is London dispersion forces.