Answer:
Explanation:
Element -
It is the basic unit of matter, which cannot be broken down into substances by any way but can be combined to form new substances.
It is a pure substance.
It classifies into metals, non-metals, metalloids and noble gases.
Example - Hydrogen, Carbon, Oxygen
Compounds -
It is a combination of two or more elements.
It is a pure substance.
Through chemical reactions, they can be broken down into metals.
Example - Water, Carbon dioxide
Mixtures -
It is a combination of two or more elements or compounds or both.
The substances combined in a mixture are in a particular ratio.
Example - Chalk powder, Washing Soda
If you hit the surface of Iron with a photon of energy and find that the ejected electron has a wavelength of .75 nm, what is the wavelength of the incoming photon in nanometers?
Answer:
The wavelength of the incoming photon is 172.8 nm
Explanation:
The wavelength of the incoming photon can be calculated with the photoelectric equation:
[tex] KE = h\frac{c}{\lambda_{p}} - \phi [/tex] (1)
Where:
KE: is the kinetic energy of the electron
h: is Planck's constant = 6.62x10⁻³⁴ J.s
c: is the speed of light = 3.00x10⁸ m/s
[tex]\lambda_{p}[/tex]: is the wavelength of the photon =?
Φ: is the work function of the surface (Iron) = 4.5 eV
The kinetic energy of the electron is given by:
[tex] KE = \frac{p^{2}}{2m} = \frac{(\frac{h}{\lambda_{e}})^{2}}{2m} [/tex] (2)
Where:
p: is the linear momentum = h/λ
m: is the electron's mass = 9.1x10⁻³¹ kg
[tex]\lambda_{e}[/tex]: is the wavelength of the electron = 0.75 nm = 0.75x10⁻⁹ m
Hence, the wavelength of the photon is:
[tex] \frac{(\frac{h}{\lambda_{e}})^{2}}{2m} = h\frac{c}{\lambda_{p}} - \phi [/tex]
[tex]\lambda_{p} = \frac{hc}{\frac{h^{2}}{2m\lambda_{e}^{2}} + \phi} = \frac{6.62 \cdot 10^{-34} J.s*3.00\cdot 10^{8} m/s}{\frac{(6.62 \cdot 10^{-34} J.s)^{2}}{2*9.1 \cdot 10^{-31} kg*(0.75 \cdot 10^{-9} m)^{2}} + 4.5 eV*\frac{1.602 \cdot 10^{-19} J}{1 eV}} = 1.728 \cdot 10^{-7} m = 172.8 nm[/tex]
Therefore, the wavelength of the incoming photon is 172.8 nm.
I hope it helps you!
TIMED HELP ASAP
19.11 g of MgSO₄ is placed into 100.0 mL of water. The water's temperature increases by 6.70°C. Calculate ∆H, in kJ/mol, for the dissolution of MgSO₄. (The specific heat of water is 4.184 J/g･°C and the density of the water is 1.00 g/mL). You can assume that the specific heat of the solution is the same as that of water.
Answer:
TIMED HELP ASAP
19.11 g of MgSO₄ is placed into 100.0 mL of water. The water's temperature increases by 6.70°C. Calculate ∆H, in kJ/mol, for the dissolution of MgSO₄. (The specific heat of water is 4.184 J/g･°C and the density of the water is 1.00 g/mL). You can assume that the specific heat of the solution is the same as that of water.
Answer:
-21.03 kJ/mol
Explanation:
∆H is enthalpy. Enthalpy is the total heat content of a system.
So we can establish that ∆H = q (heat)
The formula for heat (q)
q = cm∆T
c = specific heat capacity
m = mass of substance
∆T= change of temperature
Since we are calculating the enthalpy of the SOLUTION. We must account for both the mass of water and the mass of MgSO₄ in our q formula.
All you gotta do is plug and chug at this stage.
∆H = q = cm∆T = (4.184)(19.11+100.0)(6.70) = 3338.986808 Joules
We have now calculated the heat (aka enthalpy) of the solution.
BUT
Remember! The problem asked for enthalpy in kj....
Use this conversion factor.
1000 J = 1 kJ
3338.986808 Joules * 1kJ/1000 J = 3.338986808 kJ
We were asked to find ∆H for the dissolution of MgSO4 in units of kj/mol so we are not finished.
Take the grams of MgSO4 in the problem and convert it into moles using its molar mass.
MgSO4 molar mass = 120.3676 g
1 mol = 120.3676 g MgSO4 <---- Use this as a conversion factor
19.11 g MgSO4 * 1 mol MgSO4/120.3676 g = 0.15876365 mol MgSO4
Now that you've calculated the moles of MgSO4 in this solution. You can divide your heat by it.
q dissolution = 3.338.986808 kJ/ 0.15876365 mol = 21.03 kj/mol
Note that the problem tells us that the temperature of water increases.
This means that the water is experiencing an endothermic process (heat is being absorbed from MgSO4) . Mathematically, this would be indicated by a positive sign. ---> +q
We can assume MgSO4 is losing heat as it is placed into the water. It is experiencing an exothermic process (heat is being lost). Mathematically, this would be indicated by a negative sign. ----> -q
So if we're calculating the enthalpy for the dissolution of MgSO₄ ....the value we've arrived at must be negative.
Answer
∆H = 21.03 kj/mol :)))))
I hope that helped...I feel like my explanation was a bit convoluted.
Which statement includes all the steps in the change that is associated with the enthalpy of solution? solute separation and mixing reaction of reactants to form products. solute and solvent mixing and then separating solute separation, solvent separation, and then mixing
Answer: solute separation, solvent separation, and then mixing
Explanation:
The enthalpy change of solution simply means the amount of heat which can be released or absorbed when dissolving. The enthalpy of solution is usually expressed at constant temperature in kJ/mol.
The enthalpy of solution requires three main stages:
1. Solute separation: This is when the solute is broken down. In this case, all the intramolecular forces which holds the solute together is broken.
2. Solvent separation: This is when the solvent is broken down all the intramolecular forces which holds the solvent together is broken.
3. Mixing- In this case, the solute and the solvent is mixed for a solution.
How does the position of an object relate to the energy stored in a object?
Answer:
An object can store energy as the result of its position. For example, the heavy ball of a demolition machine is storing energy when it is held at an elevated position. This stored energy of position is referred to as potential energy. Similarly, a drawn bow is able to store energy as the result of its position
Answer:
you can see the attached file is scanned the same level of detail of the heart the heart and I am a little bit of an emergency you can see it on the heart the tree is the best of luck for tomorrow be in a few days and times are available in a while back and forth to be a good idea and latitude longitude of
Chromium forms a complex with diphenylcarbazide whose molar absorptivity is 4.17*10^4 at 540nm. Calculate the absorbance of a 7.68*10^-6 M solution of the complex at 540nm when measured in a 1.00cm cell and the transmittance of the solution.
Answer:
0.32 liters/mole cm.
Explanation:
According to Beer Lambert's law;
A= εcl
ε = molar absorptivity
c= concentration
l= path length
A= 4.17*10^4 × 7.68*10^-6 × 1
A= 0.32 liters/mole cm.
make a 450 gram solution with the mass by mass concentration of 7% how much salt and water do you need to mix
Exprese la concentración de una solución de H3PO4 al 30 % en masa y con una densidad de 1.39 g/mL en: M, y N.
Respuesta:
4.26 M; 12.8 N
Explicación:
Primer paso: Calcular la concentración volumétrica (Cv)
Usaremos la siguiente expression.
Cv = Cg × ρ
Cv = 30 g%g × 1.39 g/mL = 41.7 g%mL
Segundo paso: Calcular la molaridad
La concentración volumetrica es 41.7 g%mL, es decir, hay 41.7 gramos de soluto cada 100 mL de solución. Usaremos la siguiente fórmula para molaridad.
M = masa de soluto / masa molar de soluto × litros de solución
M = 41.7 g / 97.99 g/mol × 0.1 L = 4.26 M
Tercer paso: Calcular la normalidad
Usaremos la siguiente fórmula.
N = M × Z
donde Z para un ácido es igual al número de protones.
N = M × Z
N = 4.26 mol/L × 3 eq/mol = 12.8 N
hii pls help me to write the ionic equation
Answer:
net ionic equation
[tex]\boxed{ SO_4{}^{2-} {}_{(aq.)} + Ba^{2+} {}_{(aq.)} \rightarrow BaSO_4 {}_{(s)}} [/tex]
nguyên tử sắt có điện tích hạt nhân là 26+. trong nguyên tử, số hạt mang điện nhiều hơn số hạt không mang điện là 22. Hãy xác định số khối của nguyên tử sắt
Answer:
I don't know yr language
if excess nitrogen gas reacts with 600 cm³ of hydrogen gas at room conditions , calculate the maximum volume of ammonia produced from the reaction? the chemical question is N2 + 3H2 = 2NH3
Answer:
400 cm³ of ammonia, NH₃.
Explanation:
The balanced equation for the reaction is given below:
N₂ + 3H₂ —> 2NH₃
From the balanced equation above,
3 cm³ of H₂ reacted to produce 2 cm³ of NH₃.
Finally, we shall determine the maximum volume of ammonia, NH₃ produced from the reaction. This can be obtained as illustrated below:
From the balanced equation above,
3 cm³ of H₂ reacted to produce 2 cm³ of NH₃.
Therefore, 600 cm³ of H₂ will react to produce = (600 × 2)/3 = 400 cm³ of NH₃.
Thus, 400 cm³ of ammonia, NH₃ were obtained from the reaction.
HELLO EVERYONE PLEASE I NEED HELP WITH
Please I REALLY NEED A HELP WITH THIS PLEASE HELP ME
THIS HARRY POTTER LITERARY ESSAY
OUTLINE
1. Love and Friendship is a central theme in Harry Potter and the Philosopher's Stone. Prove that this statement is true using 2(two) different characters from the novel as examples.
Introductory Statement/ Hook:
Statement of Intent: reason A and B :
thesis reason A and B:
BODY PARAGRAPH
#1 Point #1: Introduce REASON A here, but use general statement
#1: Provide quotations from the novel to support Reason A
Explanation #1:
Proof #2:
Explanation #2:
BODY PARAGRAPH
#2 Point #2: Introduce REASON B here, but use general statements
#1: Provide quotations from the novel to support ReasonB
Explanation #1:
Proof #2:
Explanation #2:
CONCLUSION
Restate/ Summarize Thesis:
Restate/ Summarize Points:
Answer:
Ron and Hermoine
Explanation:
They always fought over petty things, but at the end, they did end up together!
(Answer for your question about love and friendship being a central theme in Harry Potter and the Philosopher's stone)
*ALSO, MY ANSWER MIGHT BE WRONG* so be sure to use a pencil just in case!
Which is another word for 10 meters in the metric system?
Answer:
Dekameter
Explanation:
Please help me
will give the brainliest!
Explanation:
a) The presence of sulfate ions in a solution can be confirmed by the reaction of barium chloride in an acidic medium.
The balanced chemical equation of the reaction is shown below:
[tex]BaCl_2(aq)+CuSO_4(aq)->CuCl_2(aq)+BaSO_4(s)[/tex]
Hence, the white precipitate is barium sulfate and its formation with the ionic equation is shown below:
[tex]Ba^2^+(aq)+SO_4^2^-(aq)->BaSO_4(aq)[/tex]
b) The presence of copper (II) ions can be confirmed by the following test:
Add potassium iodide solution to copper (II) solution.
Then a white ppt of cuprous iodide along with the liberation of iodine is observed and the entire solution attains brown color.
The chemical equation of the reaction is shown below:
[tex]2CuSO_4(aq)+4KI(aq)->Cu_2I_2(s)+I_2(s)+2K_2SO_4(aq)\\[/tex]
c)(i)Due to this reaction, the blue color of the solution becomes white.
Reddish-brown copper is deposited at the bottom of the container.
(ii)In this reaction, zinc is oxidized.
d) (i) Copper is produced at the cathode.
(ii)[tex]Cu^2^+(aq)+2e^-->Cu(s)[/tex]
(iii) The reaction that takes place at the cathode is reduction.
Reduction is gaining of electrons.
PLEASE HELP QUICK!!! How many molecules are there in 4.00 L of
glucose, C6H1206? Please show your work!!
Plants in forests take up carbon dioxide from the atmosphere during photosynthesis. They transform the carbon dioxide into plant material. When plants die, their organic matter is often worked into the soil by decomposers. Some of this organic matter remains within the soil and forest floor, and some of it is taken up by other living things.
Based on this information, what role do forests play in the carbon cycle?
A.
Forests are carbon sinks because they store carbon.
B.
Forests are carbon sinks because they do not absorb carbon dioxide when plants die.
C.
Forests are carbon sources because they emit carbon.
D.
Forests are carbon sources because they can be burned to emit carbon dioxide.
Answer: B. forests are carbon sinks because they store carbon
Explanation:forests take up carbon from the atmosphere through photosynthesis and from organic matter through decomposition. so, forests are carbon sinks because they store carbon
What is the pH of a 1.0 x 10-3 M KOH solution?
A. 10
B. 4.0
C. 11
D. 3.0
Answer:
Option C. 11
Explanation:
We'll begin by calculating the concentration of the hydroxide ion [OH¯] in the solution. This can be obtained as follow:
In solution, KOH will dissociate as follow:
KOH (aq) <=> K⁺(aq) + OH¯(aq)
From the balanced equation above,
1 mole of KOH reacted to produce 1 mole of OH¯.
Therefore, 1×10¯³ M KOH will also react to produce 1×10¯³ M OH¯.
Thus, the concentration of hydroxide ion [OH¯] in the solution is 1×10¯³ M
Next, we shall determine the pOH of the solution. This can be obtained as follow:
Concentration of hydroxide ion [OH¯] = 1×10¯³ M
pOH =?
pOH = –Log [OH¯]
pOH = –Log 1×10¯³
pOH = 3
Finally, we shall determine the pH of the solution. This can be obtained as follow:
pOH = 3
pH =?
pH + pOH = 14
pH + 3 = 14
Collect like terms
pH = 14 – 3
pH = 11
Question 8 of 10
Which of the following is made of matter?
A. Light
B. Energy
C. The sun
D. Heat
Answer: i Choose the sun
because it has mass
Explanation: matter is anything that has mass and occupies space / Volume
and the sun has mass though it is not a solid one, and is made up of matter
HOPE THIS HELPSS!!!!
b) The size of a star is a balance between
2 things. Explain this statement.
Answer:
Luminosity is the amount of light that a star radiates. The size of the star and its surface temperature determine its luminosity. Apparent magnitude of a star is its perceived brightness, factoring in size and distance, while absolute magnitude is its true brightness irrespective of its distance from earth
Explanation:
Analyse the temperature versus time graph of water, given below.
Which part of graph represent only liquid state and gaseous state and why?
Answer:
Phase C - Liquid State
Phase E - Gaseous State
Explanation:
Usually, in phases of water, we have the following;
When temperature is less than zero, it is said to be in its solid phase as ice.
When temperature is between 0 to 100, we can say it is in the liquid phase as water.
When temperature is above 100°C, It is said to be in the gaseous phase as vapour.
From the diagram;
Phase C is the only liquid state because it falls between temperature of 0°C and 100°
Also, only phase E is in the gaseous phase because the temperature is above 100°C.
Draw the following structures and name them :
I. CH3CH2(OH)
II.CH3CH2CH(CH3)C(Cl)2C(l)2CH(F)OH
III.CH3CH(CH3)CHO
IV.CH2=CH(OH)
V.CH3OCH2CH3
Answer:
hope this helps.answer is in the picture
Is this population more likely to grows slowly or quickly in the next 10 years
nobody can say it is uncertain but in my opinion it will grow quickly in the next 10 years
QUICK CHECK
Use the periodic table to select which type of bond is present and which of the listed properties is most
likely for each substance.
Substance
Type of bond
Likely property
A А
B
A
Cuzm
Ba
lonic
DO
covalent
02
С
D
metallic
Answer:
Coppell zinc,ironic bond
Explanation:
lt will give away two zinc atoms
Answer:
I will go with Sodium chlorine NaCl
How many moles are in 32g of O2?
Answer:
1 mol of O2
Explanation:
n = m/ M
n = 32/ ( 2× 15.999)
n= 1 mol of O2
A pupil has drawn the electronic structure of fluorine and the diagram is shown below. However,
mistakes have been made. State three mistakes that have been made.
Fl atomic number: 9
Fl atomic mass: 10
(ps i have two of these but can’t figure out the last)
Answer:
The number of electrons in the orbit is wrong they have to be 9 and not 10since flourine is in group 7 the number of electrons in the outer most shell has to be 7 and not 2the first shell has 8 instead of 2 electronsI hope this helps
plz solve the question and send the answer
I will give u branist, follow u ,rate u 5 star and also give u like ,plz help me
Answer:
64g of [tex]\bold{CH_{3}OH}\dashrightarrow[/tex]44.8L
vapour density of [tex]CH_{3}3OH=\frac{mass}{volume}[/tex] of [tex]\bold{CH_{3}OH}[/tex]
=64/44.8=10/7=1.43 g/l
Vapour density of [tex]\bold{CH_{3}OH}[/tex]=1.43g/l
64g of [tex]\bold{CH_{3}OH => 44.8L }[/tex]
vapour density of [tex]\small{\sf{CH_{3}3OH=\frac{mass}{volume} of } \bold{CH_{3}OH}}[/tex]
=64/44.8=10/7=1.43 g/l
Vapour density of [tex]\bold{CH_{3}OH = 1.43 g/L}[/tex]
Which diagram represents this molecule
Answer:
I think it is C
Explanation:
Hope this helps!! :)
If I'm wrong, then greatest apologies
How much heat must be transferred to 55 g of ice to change the ice's
temperature from -13°C to -5.0°C? (The specific heat capacity of ice is 2.11
J/g.°C)
How many moles of KOH are there in 27.5 mL of 0.250 M KOH?
Question 2 options:
4.31 × 10−3 mol KOH
6.88 × 10−3 mol KOH
7.24 × 10−3 mol KOH
8.13 × 10−3 mol KOH
9.21 × 10−3 mol KOH
Answer:
6.88 × 10^-3mol
Explanation:
Molarity = number of moles (n) ÷ volume (V)
According to this question, there in 27.5 mL of 0.250 M KOH, the number of moles of KOH can, therefore, be calculated as follows:
number of moles = molarity × volume
Volume of KOH = 27.5mL = 27.5/1000
= 0.0275L
n = 0.0275 × 0.250
n = 0.006875 mol
n = 6.88 × 10^-3mol
Name each compound. Do not capitalize element names. An example can be seen
below.
Ex. SF6: sulfur hexfluoride
a. H2O:
b. PC15:
C. SiF4:
d. N20
Answer:
a. H2O: dihydrogen monoxide
b. PCl5: Phosphorus pentachloride
c. SiF4: Silicon tetrafluoride
d. N20: dinitrogen oxide
what is transition state
Answer:
transition state is a point in which electrons been removed from the atom
Answer:
The highest energy structure in the reaction coordinate.
Explanation:
