Answer:
439.7nm
Explanation:
Energy of a quantum can be calculated using below formula
E=hv...........eqn(1)
But v=λ/ c .........eqn(2)
If we substitute eqn(2) into eqn(1) we have
E= hc/(λ)
Where E= energy
h= Plank's constant= 6.62607004 × 10-34 m2 kg / s
c= speed of light
c= 2.998 × 10^8 m/s
λ= wavelength= ?
But the energy was given in Kj , it must be converted to Kj/ photon for unit consistency.
Energy E= 272 kJ/mol × 1mol/6.02× 10^23
Energy= 451.83× 10^-24 Kj/ photon
E= hc/(λ)...........eqn(1)
If we make λ subject of the formula
λ= hc/E
Then substitute the values we have
λ= [(6.626 × 10^-34) × (2.998 × 10^8)]/451.83× 10^-24
λ=(0.00043965) × (1Kj/1000J) × (10^9nm/1m)
λ=439.7nm
Hence, the longest wavelength of radiation with enough energy to break carbon-sulfur bonds is 439.7nm
what is the chemical symbol for fluoride
Answer:
I think F
Explanation:
One mole of a metallic oxide reacts with one mole of hydrogen to produce two moles of the pure metal
and one mole of water. 5.00 g of the metallic oxide produces 2.32 g of the metal. What is the metallic
oxide?
Answer:
Lithium oxide, Li₂O.
Explanation:
Hello!
In this case, according to the given amounts, it is possible to write down the chemical reaction as shown below:
[tex]M_2O+H_2 \rightarrow 2M+H_2O[/tex]
Which means that the metallic oxide has the following formula: M₂O. Next, we can set up the following proportional factors according to the chemical reaction:
[tex]5.00gM_2O*\frac{1molM_2O}{(2x+16)gM_2O}*\frac{2molM}{1molM_2O}*\frac{xgM}{1molM} = 2.32gM[/tex]
Thus, we perform the operations in order to obtain:
[tex]\frac{10x}{2x+16}=2.32[/tex]
So we solve for x as shown below:
[tex]10x = 2.32(2x+16)\\\\10x = 4.64x+37.12\\\\x = \frac{37.12}{10-4.64}\\\\x= 6.93 g/mol[/tex]
Whose molar mass corresponds to lithium, and therefore, the metallic oxide is lithium oxide, Li₂O.
Best regards!
Why do we see this star pattern in the winter, but not at other times of the year? (2 points)
Answer: We see constellations at different times of the year - spring, summer, fall, & winter. This occurs because the Earth is orbiting the Sun.
Explanation:
How many moles are equal to 4.11x10^23 molecules of carbon dioxide?
Answer: 0.68 mole
Explanation:
1 mole (of any atom/molecule) = 6.02214076*10^23
0.683 moles are equal to 4.11x10²³ molecules of carbon dioxide.
What do you mean by the term mole?A mole is a unit of measurement in the International System of Units (SI) used to express an amount of a substance.
One mole is defined as the amount of a substance that contains as many elementary entities as there are atoms in 12 grams of pure carbon-12.
This number is known as Avogadro's number and is approximately 6.023 x 10²³.
Given:
For the number of moles of carbon dioxide in 4.11x10^23 molecules Avogadro's number = 6.023x10²³ particles per mole.
Therefore, the number of moles of carbon dioxide can be calculated as:
moles = number of particles / Avogadro's number
moles = 4.11x10²³ / 6.022x10²³
moles = 0.683 moles
Thus, 4.11x10²³ molecules of carbon dioxide are equal to 0.683 moles of carbon dioxide.
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what Li(s) + O2(g) -> Li2O(s) balanced is
Answer:
4 1 2Explanation:
4 Li(s) + 1 O2(g) -> 2 Li2O(s)
To calculate the atoms of an element in a given molecule, we need to multiply stoichiometry by the number that is written on the foot of that element. Therefore, the balanced equation is 4 Li(s) + 1 O[tex]_2[/tex](g) [tex]\rightarrow[/tex] 2 Li[tex]_2[/tex]O(s).
What is Balanced equation?Balanced equation is the one in which the total number of atoms of a species on reactant side is equal to the total number of atoms on product side. The mass of the overall reaction should be conserved. There are so many types of chemical reaction reaction like combination reaction, displacement reaction.
The other characteristic of balanced reaction is that physical state should be written with each compound or molecule on reactant and product side. Physical state should be written in brackets. s means solid, l means liquid, g means gas. The balanced equation for the given reaction is 4 Li(s) + 1 O[tex]_2[/tex](g) [tex]\rightarrow[/tex] 2 Li[tex]_2[/tex]O(s)
Therefore, the balanced equation is 4 Li(s) + 1 O[tex]_2[/tex](g) [tex]\rightarrow[/tex] 2 Li[tex]_2[/tex]O(s).
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pertain to the following class, Point:
public class Point {
private double x;
private double y;
public Point() {
this (0, 0);
}
public Point(double a, double b) {
/* missing code */
}
// ... other methods not shown
}
Which of the following correctly implements the equals method?
public boolean equals(Point p) {
return (x == p.x && y == p.y );
}
public void equals(Point p) {
System.out.println(x == p.x && y == p.y);
}
public void equals(Point p) {
return (x == p.x && y == p.y );
}
public boolean equals(Point p) {
return (x == Point.x && y == Point.y);
}
public boolean equals(Point p) {
System.out.println(x == p.x && y == p.y);
}
_______________________
The default constructor sets x and y to (0, 0) by calling the second constructor. What could be used to replace /* missing code */ so that this works as intended?
a = 0;
b = 0;
this (x, y);
this(0, 0);
x = a;
y = b;
a = x;
b = y;
_____________________
Which of the following correctly implements a mutator method for Point?
public double getX() {
return x;
}
public void setCoordinates (double a, double b) {
x = a;
y = b;
}
None of the items listed.
public double getX() {
return a;
}
public void setCoordinates (double a, double b) {
Point p = new Point(a,b);
}
b = 0;
this (x, y);
this(0, 0);
x = a;
y = b;
a =x
This above solution is just according to the public boolean equals(Point p) { return (x == p.x && y == p.y ); and public void equals(Point p) { System.out.println(x == p.x && y == p.y);}
What is public void?An abstract class contains a pure virtual function. Pure virtual class cannot be instantiated but it can be subclassed and the subclass can provide an implementation of the function.
A virtual function declaration in the class is preceded by the virtual keyword. For example, virtual void print();
A pure virtual function declaration is followed by '=0;'
public: virtual void print()=0;
The main method header is written as public static void main(String[] args). A main method is something that is required in Java. You must have at least one class with a method named main. In Java, main is a static method, which means that it is part of its class but not parts of objects.
Therefore, This above solution is just according to the public boolean equals(Point p) { return (x == p.x && y == p.y ); and public void equals(Point p) { System.out.println(x == p.x && y == p.y);}
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You find yourself in a room with dark gray walls. Medeleev’s image says, “This element is essential for plant life to thrive and is found in heavy clay minerals and the ash from your campfire.” What element are these walls made from?
Answer:
juvn hgf jb ujvi i junk food sux
Explanation:
In order to inexpensively determine the contamination level of a sample of water, a new test is known to yield almost exactly the same value when repeatedly used on samples from the same container of water. However, these individual values are not close to the true average contamination level for the large container. The concern with using this new, cheaper test to determine the contamination level for a single sample of water is that this measurement method is not
Answer:
The correct answer is - valid.
Explanation:
In this case, there is consistency in the results measures in the experiment which makes this method reliable. The consistency of a measure is referred to the reliability.
It is also given that the level of contamination of individual containers as per the average parameter of the contamination of large containers which makes this method not valid as the measurement method is how correctly it measures the true value of the parameter.
Thus, the correct answer is - method is reliable, but not valid.
How many moles are in 3.01 x 10^23 atoms of zinc?
Answer:
What is ^ for?
Explanation:
a golf ball is hit at a distance of 300 yards in 10 seconds what is the speed of the golf ball
Answer:
30 yard per second
Explanation:
300/10 = 30
1. A gas has a volume of 5.30 mL and a mass of 24.10 grams. What is the
density?
Answer:
4.5472g/ml rounded of to 4 s.f
Explanation:
Density= Mass/ Volume
Define the following Vocabulary words
1. Archae Bacteria
2. Bacteria
3. Eukarya Kingdom
4. Domain
The following chemical reaction occurs.
2H2O2
2H20 + O2
How many atoms of hydrogen are involved in the reaction?
Answer: B. 4
Explanation:
The process of the body changes that cause a child's body to become capable of reproduction
Answer:
The process is called Puberty.
Pure acetic acid is often called glacial acetic acid because it is purified by fractional freezing at its melting point of 16.6 °C. At 1 atm, a flask containing several moles of acetic acid at 16.6 °C is briefly lowered into an infinitely large ice-water bath. When it is removed it is found that exactly 1 mol of acetic acid has frozen. Given: ΔH_fusion,acetic acid = 11.45kJ/mol and ΔH_fusion, H2O= 6.01 kJ/mol.
Required:
a. What is the change in entropy of the acetic acid?
b. What is the change in entropy of the water bath?
c. Now consider that the water bath and acetic acid are the same system. What is the entropy change for the combined system? Is the process reversible or irreversible? Why?
Answer:
Explanation:
a ) ΔH_fusion of acetic acid is 11.45 kJ / mol . It means 11.45 kJ of heat will be released when 1 mole of acetic acid will freeze . During this process temperature of acetic acid will be constant .
Temperature of acetic acid T = 16.6⁰C = 273 + 16.6 K = 289.6 K .
By definition change in entropy
ΔS = dQ / T
= dH / T
As temperature remains constant during withdrawal of heat
ΔS = ΔH / T
T = 289.6 K .
ΔH = - 11.45kJ
ΔS = - 11.45kJ / 289.6
= - 11450 / 289.6
= - 39.53 J
It will be negative as heat is released by acetic acid .
b )
Heat amounting ΔH will be absorbed by water bath so its entropy will be increased . As water bath is very large , temperature of bath also will remain constant at 289.6 K .
Increase in entropy of water bath =
ΔS = ΔH / T
T = 289.6 K .
ΔH = 11.45kJ
ΔS = 11.45kJ / 289.6
= 11450 / 289.6
= 39.53 J
c )
consider that the water bath and acetic acid are the same system : --
Total change in the heat content of the system
= 289.6 - 289.6 = 0
So for the whole system
ΔQ =ΔH = 0
Change in entropy is zero .
Δ G = ΔH - TΔS
= ΔH - ΔH = 0
ΔG = 0
Change in entropy is zero .
How many moles of O2 are needed to produce 2.5 moles of water?
Answer:
Mass of oxygen = 16 * 1.25 = 20 g
Explanation:
How many moles of aluminum will be produced from 30.0 g of Al2O3 in the following reaction?
2A1203 - 4A + 302
Moles of aluminum produced = 0.588
Further explanationGiven
30 g of Al2O3
Reaction
2Al203 ⇒ 4Al + 302
Required
moles of aluminum
Solution
mol Al2O3 :
= mass : MW
= 30 : 101,96 g/mol
= 0.294
From the equation, mol Aluminum :
= 4/2 x mol Al2O3
= 4/2 x 0.294
= 0.588
Accreditation of laboratories that do forensic investigations is:_________
a. always required
b. done voluntarily
c. done using independent nongovernmental agencies such as ASTM and ISO
d. done by a special government agency to insure uniformity of testing and results across all laboratories is never done since this
e. is expensive and does not improve the results obtained by the laboratory
Answer:
a. always required
Explanation:
Accreditation of laboratories is a mandatory requirement for forensic science providers. To manage the quality of services provided by the forensic laboratories, Accreditation, Certification, and Interagency Working Group have found it necessary to make the accreditation of forensic laboratories mandatory.
This will instill confidence in the public and ensure that the services rendered by them are always accurate and up to standard.
For the reaction between zinc metal and hydrochloric acid (aqueous) producing zinc chloride (aqueous) and hydrogen gas
write a balanced equation for this reaction
classify the reaction
Answer: Zn + 2HCl —> ZnCl2 + H2 redox
Explanation:
H+ reduced to H
Zn oxidised to Zn++
The diagram shows the electron configuration around the chlorine nucleus. Chlorine has 17 protons.
CI
Which of the following correctly completes the statement?
Chlorine has valence electrons, and the effective nuclear charge, Zett, for the chlorine atom shown is
O A. 7,7+
OB. 7,7-
O C. 10,7-
D. 17, 7+
Answer: A. [tex]7,+7[/tex]
Explanation:
Valence electrons are the number of electrons constituting the outermost shell of an atom. It is also defined as the electrons that take part in the formation of a chemical bond.
The atomic number of chlorine is 17 as it has 17 protons and the electronic configuration will be 2,8,7. Thus the electrons present in the outermost shell are 7 and hence the valence electrons are 7.
Effective nuclear charge is the net positive charge experienced by valence electrons. It is calculated by: Zeff = Z – S
where Z = atomic number , S = number of shielding electrons.
Thus for Chlorine , [tex]Z_{eff}=17-10=7[/tex]
plz help as soon as you can
Oil of Vitriol is a substance that humankind has used for thousands of years! Today the substance is known by its scientific name sulfuric acid and has the molecular formula H2SO4. What is the molar mass of H2SO4?
Question 2 options:
49.067 g/mol
73.29 g/mol
98.08 g/mol
148.72 g/mol
Answer:
98.08 g/mol
Explanation:
Hope this helps.
Earths outer core is made of ___
Answer:
iron and nickel (liquid metal )
Explanation:
The outer core is the third layer of the Earth. It is the only liquid layer, and is mainly made up of the metals iron and nickel, as well as small amounts of other substances. The outer core is responsible for Earth’s magnetic field. As Earth spins on its axis, the iron inside the liquid outer core moves around
Answer:
The outer core is the third layer of the Earth. It is the only liquid layer, and is mainly made up of the metals iron and nickel, as well as small amounts of other substances.
Explanation:
What is the density of an object that has a mass of 28.1g and a volume of 96.2mL? Select the correct answer below: 0.292g/mL 2703g/mL 1.00g/mL 3.42g/mL
Answer:
0.292 g/mL.
Explanation:
From the question given above, the following data were obtained:
Mass of object = 28.1 g
Volume of object = 96.2 mL
Density of object =..?
Density of an object is simply defined as the mass of the object per unit volume of the object. Mathematically, it can be expressed as:
Density = mass / volume
With the above formula, we can obtain the density of the object as follow:
Mass of object = 28.1 g
Volume of object = 96.2 mL
Density of object =..?
Density = mass / volume
Density = 28.1 / 96.2
Density of object = 0.292 g/mL
Thus the density of the object is 0.292 g/mL
What element has 12 protons, 12 neutrons and 12 electrons?
Answer:
magnesium atom
The most common and stable type of magnesium atom found in nature has 12 protons, 12 neutrons, and 12 electrons
a reaction vessel contains a small piece of magnesium metal and air (20%) of which is oxygen gas. The mixture is ignited and burns with a burst of light and heat, producing solid magneisum oxide. The mass of mgO, however, is less than the initital mass of magnesium and oxygen combined. What loss of mass
Answer: see below
Explanation:
Mg burning in air gives MgO and a smaller amount of Mg3N2
2Mg+O2=2MgO. 2*24.3+32=2*40.3
3Mg+N2=Mg3N2
Ignoring the nitride, MgO loss of mass during the reaction can be ascribed to
(1) relativistic loss as energy (too small to be measurable)
(2) During the reaction, which is strongly exothermic, a fraction f the material is blown off as tiny particles which adhere to the vessel.
True or false questions?
Most metal elements are brittle and do not conduct electricity. True or False
Any element can be identified by counting the protons in its neucleus. True or False
All Earths matter is made from the combination of about 100 elements. True or false
Answer:
1. False 2.True3.True? Unsure
Explanation:
What does CoH12O6 tell you about the glucose molecule?
Answer:
Glucose = C6H12O6
molecular mass = 6(12) + 12(1) + 6(16)
= 72 + 12 + 96
= 180 g
Explanation:
Glucose has a chemical formula of: C6H12O6 That means glucose is made of 6 carbon atoms, 12 hydrogen atoms and 6 oxygen atoms. ... Glucose is produced during photosynthesis and acts as the fuel for many organisms.
Compare the two shampoo
Answer:
Explanation:
I think you forgot to attach an image here!
True or False Weather is the condition or earth's atmosphere at a certain place and time.
Answer:
True
Explanation:
Weather is short term, climate is over the long term
Answer:
true, different weather patterns are found all around the world at different times, there could be a hurricane in the gulf of mexico and as a result of the storm tornadoes could break out in texas
Explanation:
In a heterogeneous chemical reaction requiring the use of a solid catalyst, the rate of the reaction could not be increased by increasing the concentration of reactants, but was doubled by doubling the amount of solid catalyst added. This probably indicated that
Answer:
The active sites on the initial amount of catalyst were fully saturated
Explanation:
A catalyst is a substance which alters the rate of a chemical reaction but largely remains unaltered at the end of the reaction. A catalyst has an active site which enables it to catalyze a reaction.
The active site provides the best possible orientation for reactant molecules to collide in order to form products.
When the active sites are not fully saturated with reactant molecules, more reactant molecules can bind and the reaction can proceed much faster. However, if the active sites of the catalysts are fully saturated, the reaction has maximum velocity and cannot go anymore faster.
Addition of more catalyst molecules can however make the reaction proceed faster as a it provides more active sites for reaction for the reactants.