Answer:
C. either A or B
Explanation:
To calculate the energy of a photon returning to its ground state, we required either the frequency or the wavelength. Often times, not both.
The wavelength of a photon can be derived by;
E = hf
or
E = [tex]\frac{hc}{wavelength}[/tex]
h is the Planck's constant
c is the speed of light
f is the frequency
A compound composed of 3.3% H, 19.3% C, and 77.4% O3.3% H, 19.3% C, and 77.4% O has a molar mass of approximately 60 g/mol.. What is the molecular formula of the compound?
Answer:
Molecular formula of the compound = H₂CO₃
Explanation:
First, the empirical formula of the compound is determined
Percentage by mass of each element is given as shown below:
H = 3.3% ; C = 19.9%; O = 77.4%
Mole ratio of the elements= percentage mass/ molar mass
H = 3.3/ 1 = 3.3
C = 19.3/12 = 1.6
O = 77.4/16 = 4.8
whole number ratio is obtained by dividing through with the smallest ratio
H = 3.3/1.6; C = 1.6/1.6; O = 4.8/1.6
H : C : O = 2 : 1 : 3
Empirical formula = H₂CO₃
Molecular formula/mass = n(empirical formula/mass)
60 = n(2*1 + 12*1 + 16*3)
60 = n(62)
n = 60/62 = 0.96
n is approximately = 1
Therefore, molecular formula of the compound = (H₂CO₃) * 1
Molecular formula of the compound = H₂CO₃
The molecular formula of a compound composed of 3.3% H, 19.3% C, and 77.4% O and a molar mass of approximately 60 g/mol is CH2O3.
HOW TO CALCULATE MOLECULAR FORMULA:
The molecular formula of an unknown compound can be calculated from the empirical formula. The empirical formula can be calculated as follows:C = 19.3% = 19.3gH = 3.3% = 3.3gO = 77.4% = 77.4gFirst, we calculate the number of moles in each element by dividing by their respective atomic mass. C = 19.3g ÷ 12g/mol = 1.61molH = 3.3g ÷ 1g/mol = 3.3molO = 77.4g ÷ 16g/mol = 4.84molNext, we divide by the smallest mole value. C = 1.61mol ÷ 1.61 = 1 H = 3.3mol ÷ 1.61 = 2.05O = 4.84mol ÷ 1.61 = 3.01Approximately, the empirical ratio of CHO is 1:2:3. Hence, the empirical formula is CH2O3. {CH2O3}n = 60g/mol{12 + 2 + 48}n = 6062n = 60n = 60 ÷ 62n = 0.968n = 1Therefore, the molecular formula of a compound composed of 3.3% H, 19.3% C, and 77.4% O and a molar mass of approximately 60 g/mol is CH2O3.Learn more at: https://brainly.com/question/21280037?referrer=searchResults
Silver has a density of 10.5 g/cm³, and gold has a density of 19.3 g/cm³. Which would have a greater mass, 5 cm³ of silver or 5 cm³ of gold?
Gold have a greater mass
Further explanationDensity is a quantity derived from the mass and volume
Density is the ratio of mass per unit volume
The unit of density can be expressed in g/cm³ or kg/m³
Density formula:
[tex]\large {\boxed {\bold {\rho ~ = ~ \frac {m} {V}}}}[/tex]
ρ = density
m = mass
v = volume
mass of Silver :[tex]\tt mass=\rho\times V\\\\mass=10.5\times 5=52.5~g[/tex]
mass of Gold :[tex]\tt mass=\rho\times V\\\\mass=19.3\times 5=96.5~g[/tex]
A 12.0 m hcl solution has a density of 1.18 g ml. What is the concentration of tthis solution in weight percent and moliarty?
Answer:
Percentage of HCL = 37.11 % (Approx)
Molarity = 16.17 m (Approx)
Explanation:
Given:
Molarity = 12.0 M of hcl
Density = 1.18 g/ml
Computation:
1L of hcl solution contains = 12 moles
Mass = Moles x Molar mass
Mass of HCl = 12 x 36.5
Mass of HCl = 438 g = 0.438 kg
Mass of 1 L solution = 1.18 x 1,000 ml
Mass of 1 L solution = 1180 g
Percentage of HCL = [438/1180]100
Percentage of HCL = 37.11 % (Approx)
Molarity = 12 / [1.18 - 0.438]
Molarity = 12 / [0.742]
Molarity = 16.17 m (Approx)
. Calculate the entropy change associated with the isothermal compression of 0.720 mol of an ideal gas from 24.32 L to 3.90 L.
Answer:
[tex]$\Delta S = -10.95 \ \frac{J}{K}$[/tex]
Explanation:
Given :
Number of mole, n = 0.720 mol
Initial volume, [tex]$V_1$[/tex] = 24. 32 L
Final volume, [tex]$V_2$[/tex] = 3.90 L
We know entropy change,
[tex]$\Delta S = c_V\ln \left(\frac{T_2}{T_1}\right) + n R \ln \left(\frac{V_2}{V_1}\right)$[/tex]
For isothermal compression temperature constant,
[tex]$\Delta S = n R \ln \left(\frac{V_2}{V_1}\right)$[/tex]
[tex]$\Delta S = 0.720 \times 8.314 \times \ln \left(\frac{3.90}{24.32}\right)$[/tex]
[tex]$\Delta S = -10.95 \ JK^{-1}$[/tex]
[tex]$\Delta S = -10.95 \ \frac{J}{K}$[/tex]
The isotope of carbon used in archaeological dating is 14^6C . How many protons, neutrons, and electrons does an atom of 14^6C have?
Answer:
6
8
6
Explanation:
Isotope given:
¹⁴₆C
In specie written as this;
Superscript = Mass number
Subscript = Atomic number
To find the protons, it is the same as the atomic number;
Protons = Atomic number = 6
Neutrons have no charges;
Neutrons = Mass number - Atomic number =
Neutrons = 14 - 6 = 8
The number of electrons is the same as the atomic number = 6
The velocity of a car changes from 10 m/s east to 30 m/s east in 4 seconds.
What is the acceleration of the car?
A. 5 m/s2 east
B. 10 m/s2 west
c. 10 m/s2 east
D. 5 m/s2 west
Answer:
5m/s²
Explanation:
Given parameters:
Initial velocity = 10m/s due east
Final velocity = 30m/s due east
Time = 4s
Unknown:
Acceleration of the car = ?
Solution:
Acceleration is the rate of change of velocity with time.
Mathematically;
Acceleration = [tex]\frac{v - u}{t}[/tex]
v is the final velocity
u is the initial velocity
t is the time taken
Insert the parameters and solve;
Acceleration = [tex]\frac{30 - 10}{4}[/tex] = 5m/s²
Calculate the molar mass of Al(CH3O2)3
Answer:
The molar mass and molecular weight of Al(CH3CO2)3 is 204.1136.
Explanation:
Answer:
168.1 g/mol
General Formulas and Concepts:
Chemistry
Reading a Periodic TableExplanation:
Step 1: Define
Al(CH₃O₂)₃
Step 2: Find molar masses
Molar Mass of Al - 26.98 g/mol
Molar Mass of C - 12.01 g/mol
Molar Mass of H - 1.01 g/mol
Molar Mass of O - 16.00 g/mol
Molar Mass of Al(CH₃O₂)₃ - 26.98 + 3(12.01) + 9(1.01) + 6(16.00) = 168.1 g/mol
Calculate the pH of the cathode compartment solution if the cell emf at 298 K is measured to be 0.660 V when (Zn^2+)=0.22 M and(P_H2)= 0.87atm.
Answer:
pH = 2.059
Explanation:
At the Cathode:
The reduction reaction is:
[tex]2H^+ + 2e^- \to H_2 \ \ \ \mathbf{E^0_{red}= 0.00 \ V}[/tex]
At the anode:
At oxidation reaction is:
[tex]Zn \to Zn^{2+} +2e^- \ \ \ \mathbf{E^0_{ox} = 0.76 \ V}[/tex]
The overall equation for the reaction is:
[tex]\mathbf{Zn + 2H^+ \to Zn^{2+} + H_2}[/tex]
The overall cell potential is:
[tex]\mathbf{E^0_{cell}= E^0_{ox} + E^0_{red}}[/tex]
[tex]\mathbf{E^0_{cell}= 0.76 \ V +0.00 \ V}[/tex]
[tex]\mathbf{E^0_{cell}= 0.76\ V}[/tex]
Using the formula for the Nernst equation:
[tex]E = E^0 - ( \dfrac{0.0591}{n})log (Q)\\[/tex]
where;
E = 0.66
(Zn^2+)=0.22 M
Then
[tex]0.66 =0.76- ( \dfrac{0.0591}{2})log \bigg ( \dfrac{[Zn^{2+} ] PH_2}{[H^+]^2} \bigg )[/tex]
[tex]0.66 =0.76- 0.02955 * log \bigg ( \dfrac{0.22*0.87}{[H^+]^2} \bigg )[/tex]
3.4 = log ( 0.1914) - 2 log [H⁺]
3.4 = -0.7180 - 2 log [H⁺]
3.4 + 0.7180 = - 2 log [H⁺]
4.118 = - 2 log [H⁺]
pH = log [H⁺] = 4.118/2
pH = 2.059
The pH of the solution as described in the question is 2.7.
The equation of the reaction is;
Zn(s) + 2H^+(aq) ----> Zn^2+(aq) + H2(g)
The partial pressure of hydrogen can be converted to molarity using;
P= MRT
M = P/RT
M = 0.87atm/0.082 LatmK-1mol-1 × 298 K = 0.036 mol/L
We have to obtain the reaction quotient
Q = [Zn^2+] [H2]/[H^+]^2
Q = [0.22 ] [0.036]/[H^+]^2
Recall that, from Nernst equation;
E = E° - 0.0592/nlog Q
E° = 0.00V - (-0.76V) = 0.76V
0.660 = 0.76 - 0.0592/2logQ
0.660 - 0.76 = - 0.0592/2logQ
-0.1 = - 0.0592/2logQ
-0.1 × 2/ - 0.0592 = logQ
3.38 = log Q
Q = Antilog (3.38)
Q= 2.39 × 10^3
Now;
2.39 × 10^3 = [0.22 ] [0.036]/[H^+]^2
2.39 × 10^3 = 7.92 × 10^-3/[H^+]^2
[H^+]^2 = 7.92 × 10^-3/2.39 × 10^3
[H^+] = 1.82 × 10^-3
pH = -log[H^+]
pH = -log[ 1.82 × 10^-3]
pH = 2.7
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Which of the following would be a clue that a rock is metamorphic?
A It has a complete fossil in it.
B It has gas bubbles.
с It is very soft.
D It has ribbon-like layers, or bands.
How many moles of H20 are required to react completely with 7.30 moles of NO2?
3NO2(g) + H20(1)
NO(g) + 2HNO3(aq)
1.86 mol
2.19 mol
2.43 mol
6.12 mol
7.30 mol
Answer:
2.43 moles of water are required.
Explanation:
Given data:
Moles of H₂O required = ?
Moles of NO₂ present = 7.30 mol
Chemical equation:
3NO₂+ H₂O → NO + 2HNO₃
Now we will compare the moles of NO₂ and H₂O.
NO₂ : H₂O
3 : 1
7.30 : 1/3×7.30 = 2.43 mol
A 49 gram sample of an unknown metal requires 717 Joules of energy to heat it from 30.5◦C to 101◦C. What is the specific heat of this metal? Answer in units of J/g · ◦ C.
Answer:
The specific heat capacity of unknown metal is calculated using the following formula
Q=MC delta T where
Q= heat(862 j)
M= mass (17 g)
C= specific heat capacity=?
delta T = change in temperature ( 35-10= 25 c)
by making C the subject of the formula C=Q/m delta T
= 862 j/( 17 g x25 c) = 2.028 j/g/c
Explanation:
10. How many electrons did Br?- gain or lose?
It did not gain or lose any electrons, it lost a proton.
It did not gain or lose any electrons, it gained a proton.
O It lost one electron because it has a charge of negative one.
0 It gained one electron because it has a charge of negative one.
What is the Molarity 2 mol of KL discovered in 1 L water
Answer:
Molarity = 2 M
Explanation:
Given data:
Molarity of solution = ?
Number of moles = 2 mol
Volume of water = 1 L
Solution:
Molarity is used to describe the concentration of solution. It tells how many moles are dissolve in per litter of solution.
Formula
Molarity = number of moles of solute / L of solution
Molarity = 2 mol / 1 L
Molarity = 2 M
How many atoms of Chlorine would there be in 6.8 mol of Cl?
Answer:
241.08039999999588
Explanation:
If 42.389 g of Fe3Br2 is dissolved in enough water to give a total volume of 750 mL, what is the molarity of the solution
Answer:
[tex]M=0.173M[/tex]
Explanation:
Hello!
In this case, since the molarity of a solution is defined in terms of the moles of solute divided by the volume of the solution in liters and has units of mol/L or M:
[tex]M=\frac{n}{V}[/tex]
For the solute, Fe3Br2, which has a molar mass of 327.3430 g/mol, the moles in 42.389 g are:
[tex]n=42.389g*\frac{1mol}{327.3430g} =0.12949mol[/tex]
Thus, since the volume in liters is 0.750 L from those given 750 mL, the molarity turns out:
[tex]M=\frac{0.12949mol}{0.750L}\\\\M=0.173M[/tex]
Best regards!
It isa sex characteristic that has direct relation to sexual reproduction?what is it..
Which of the following examples from everyday life are made possible or explained possible or explained by modern chemistry
Answer: Where is the folowing?
Explanation:
How many moles of water would be produced from 3 moles of oxygen in the following reaction? Don’t forget to include units in your answer.
PLZHELP I'LL AWARD BRAINLIEST
Answer:
6 mol H₂O
General Formulas and Concepts:
Chemistry
StoichiometryExplanation:
Step 1: Define
RxN: 2H₂ + O₂ → 2H₂O
Given: 3 moles O₂
Step 2: Stoichiometry
[tex]3 \ mol \ O_2(\frac{2 \ mol \ H_2O}{1 \ mol \ O_2} )[/tex] = 6 mol H₂O
Step 3: Check
We are given 1 sig fig.
Our final answer has 1 sig fig, so no need to round.
Solve each of the following problems using dimensional analysis.
Answer:
12ml should be the answer
Explanation:
Which compound contains a double bond?
ethene (C2H4)
chlorine (C12)
ammonia (NH3)
methane (CH)
Answer:
ethene
Explanation:
just took the test :D
5. What is the speed (Velocity) of a cyclist who covers 10 km (convert to meters
first!) in 14 minutes and 30 seconds? Remember time must be in seconds first!
[tex]\mathfrak{\huge{\pink{\underline{\underline{AnSwEr:-}}}}}[/tex]
Actually Welcome to the Concept of the Kinematics.
Here, we know that, Velocity = Distance / Time,
So here, Distance = 10km = 10×1000 = 10000 metres.
, Time = 14 min 30 sec = 870 seconds,
so now, we get velocity as,
=> V = 10000 ÷ 870 => 11.49 m/s .
Hence, Velocity is 11.49 m/s.
What is accretion?????
Answer:
the process of growth or increase, typically by the gradual accumulation of additional layers or matter.
Explanation:
Answer:
The process of growth or increase, typically by the gradual accumulation of additional layers or matter.
Explanation:
What type of wave is shown here?
:transverse wave
:longitudinal wave
Which of the following is a consequence of humans using fossil fuels?
O A. All of these
B. Rising sea level
C. Destruction of habitats
D. More severe storms
A balloon is filled to a volume of 1.50 L with 3.00 moles of gas at 25 °C. With pressure and temperature held constant, what will be the volume (in L) of the balloon if 0.80 moles of gas are added?
We know, when temperature and pressure is constant :
[tex]\dfrac{V_1}{n_1}=\dfrac{V_2}{n_2}[/tex] ....1)
[tex]n_1 = 3\ moles,\ V_1 = 1.50\ L[/tex]
[tex]n_2 = 3 + 0.80 = 3.80 \ moles[/tex]
Let, final volume is [tex]V_2[/tex].
Putting all values in equation 1), we get :
[tex]\dfrac{V_1}{n_1}=\dfrac{V_2}{n_2}\\\\\dfrac{1.50}{3}=\dfrac{V_2}{3.80}\\\\V_2 = \dfrac{1.50\times 3.80}{3}\\\\V_2 = 1.9\ L[/tex]
Therefore, volume (in L) of the balloon if 0.80 moles of gas are added is 1.9 L.
Hence, this is the required solution.
About 25% of the world's population lives:
in the United States
without access to energy
in industrialized areas
near nuclear power plants
Answer:
I believe it is "in industrialized areas"
Explanation:
According to Calvert Academy it says "Only 25% of the world's population lives in industrial areas. Hope this helps :)
help me plz plz plz plz plz plz plz plz plz plz plz plz plz :(
Do you think these molecules are larger or smaller than a cell in the human body? Explain your answer.
Molecules which have a larger size as compared to pores of cell membrane then they can't pass through it.
Small size moleculesWater, carbon dioxide, glucose and oxygen are some of the molecules that can pass through the cell membrane of the cell by the process of diffusion while on the other hand, large molecules such as sugars and proteins can't enter inside the cell due to their large size.
Pores present in cell membraneThe cell has semipermeable membrane which has small pores. Through these pores small size materials can pass through whereas large molecules can't pass through it due to their large size so we can conclude that molecules which have a larger size as compared to pores of cell membrane then they can't pass through it.
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PLS HELP THE QUESTION IS ON THE PICTURE
Concepts used:
1 mole of an element or a compound has 6.022 * 10²³ formula units
So, we can say that: Number of formula units = number of moles * 6.022*10²³
number of moles of an element or a compound = given mass/molar mass
__________________________________________________________
003 - Number of CaH₂ formula units in 6.065 grams
Number of Moles:
We know that the molar mass of CaH₂ is 42 grams/mol
Number of Moles of CaH₂ = given mass/molar mass
Number of moles = 6.065 / 42
Number of moles = 0.143 moles
Number of Formula units:
Number of formula units = number of moles * 6.022*10²³
= 0.143 * 6.022 * 10²³
= 0.86 * 10²³ formula units
__________________________________________________________
004 - Mass of 6.34 * 10²⁴ formula units of NaBF₄
Number of Moles:
We mentioned this formula before:
Number of formula units = number of moles * 6.022*10²³
Solving it for number of moles, we get:
Number of moles = Number of Formula units / 6.022* 10²³
replacing the variable
Number of moles = 6.34 * 10²⁴ / 6.022*10²³
Number of moles= 10.5 moles
Mass of 10.5 moles of NaBF₄:
Molar mass of NaBF₄ = 38 grams/mol
Mass of 10.5 moles = 10.5 * molar mass
Mass of 10.5 moles = 10.5 * 38
Mass = 399 grams
__________________________________________________________
005 - Number of moles in 9.78 * 10²¹ formula units of CeI₃
Number of Moles:
We have the formula:
Number of moles = Number of Formula units / 6.022* 10²³
replacing the variables
Number of Moles = 9.78 * 10²¹ / 6.022*10²³
Number of Moles = 1.6 / 10²
Number of Moles = 1.6 * 10⁻² moles OR 0.016 moles
Match the description to the advancement
Answer:
i podwmk
Explanation:
What is meant by the "frequency of light"? What symbol is used for it, and what is the SI unit for frequency?
Answer: Units. The SI derived unit of frequency is the hertz (Hz), named after the German physicist Heinrich Hertz. One hertz means that an event repeats once per second.
The frequency is the number of waves that pass a point in space during any time interval, usually one second. We measure it in units of cycles (waves) per second, or hertz. The frequency of visible light is referred to as color, and ranges from 430 trillion hertz, seen as red, to 750 trillion hertz, seen as violet.
Frequency of an electromagnetic wave is the number of wave cycles per unit time. The SI unit of frequency is Hertz or Hz. Frequency is represented by the symbol v called neu.
What is electromagnetic wave?Waves are propagation or transfer of energy through air or vacuum. An electromagnetic wave is associated with a combined electric field and magnetic field.
Waves are associated with characteristic frequency and wavelength. Wavelength of a wave is the distance between its two consecutive crests or troughs.
Frequency of a wave is the number of wave cycles per unit time. Its is expressed in the unit of Hertz or Hz. Frequency and wavelength are in inverse relation. The shortest waves have greater energy and greater frequency.
Frequency is inverse of time of propagation. So that it can also be used in s⁻¹ which is equal to one hertz.
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