Answer:
52.9 KJmol-1
Explanation:
From;
log(k2/k1) = Ea/2.303 * R (1/T1 - 1/T2)
The temperatures must be converted to Kelvin;
T1 = 25° C + 273 = 298 K
T2= 35°C + 273 = 308 K
R= gas constant = 8.314 JK-1mol-1
Substituting values;
log 2 = Ea/2.303 * 8.314 (1/298 - 1/308)
Ea = 52.9 KJmol-1
2) Why do transition elements show variable
oxidation states
Answer:
These elements show variable oxidation state because their valence electrons in two different sets of orbitals, that is (n-1)d and ns. The energy difference between these orbitals is very less, so both the energy levels can be used for bond formation. Thus, transition elements have variable oxidation states
Which event takes place first in the stages before the brith of a star
Answer:
nuclear fusion
Explanation:
gravity pulls gas and dust together a protostar forms as mass increases nuclear fusion begins under high pressure
Select the molecule where free rotation around one or more bonds is not possible. Group of answer choices N2H4 C2Cl4 NH3 C2H6 CCl4
Answer:
C₂Cl₄
Explanation:
To know if free rotation around a bond in a compound is possible, we need to see the structure of the compound (picture in attachment).
In single bonds, which are formed by σ bonds, the atoms are not fixed in a single position, and free rotation is permitted.
Double and triple bonds are formed by a σ bond and one or two π bonds, respectively. These bonds do not allow rotation, since it is not possible to twist the ends without breaking the π bond.
The chloroethylene (C₂Cl₄) has two carbons with an sp2-sp2 hybridization, they are bonded together by a double bond. Free rotation on this bond is not possible, because six atoms, including the carbon atoms, doubly bonded and the four chlorine atoms bonded to them, must be on the same plane.
The fact that the four new elements are Period 7 of the table means that they all
A.have seven shells of electrons
B. have seven valence electrons
C. form ions with charges of 7+
D. have an effective nuclear charge of 7+
Answer:
C
Explanation:
form ions with charges of 7+
What mass of Al(OH)3 is needed to completely react with 17.9g of HCl?
Answer:
12.8 g
Explanation:
Step 1: Write the balanced neutralization reaction
Al(OH)₃ + 3 HCl ⇒ AlCl₃ + 3 H₂O
Step 2: Calculate the moles corresponding to 17.9 g of HCl
The molar mass of HCl is 36.46 g/mol.
17.9 g × 1 mol/36.46 g = 0.491 mol
Step 3: Calculate the moles of Al(OH)₃ that completely react with 0.491 moles of HCl
The molar ratio of Al(OH)₃ to HCl is 1:3. The reacting moles of Al(OH)₃ are 1/3 × 0.491 mol = 0.164 mol
Step 4: Calculate the mass corresponding to 0.164 moles of Al(OH)₃
The molar mass of Al(OH)₃ is 78.00 g/mol.
0.164 mol × 78.00 g/mol = 12.8 g
Ocean waves are hitting a beach with a frequency of 0. 100 HZ the average weight for length is 15.0 M what is the average speed
Answer:
Speed of wave = 1.5 m/s
Explanation:
Given data:
Frequency of wave = 0.100 Hz
wavelength of wave = 15.0 m
Average speed = ?
Solution:
Speed of wave = frequency × wavelength
Speed of wave = 0.100 Hz × 15.0 m
Hz = s⁻¹
Speed of wave = 1.5 m/s
The mass of water in a single popcorn kernel was found to be 0.905 grams after it popped at a temperature of 175 °C. Using the information given in the Introduction, calculate the amount of heat in kilojoules required to pop this single kernel if the room temperature was recorded to be 21.0 °C.
Answer:
0.583 kilojoules
Explanation:
The amount of heat required to pop a single kernel can be calculated using the formula as follows:
Q = m × c × ∆T
Where;
Q = amount of heat (J)
m = mass of water (g)
c = specific heat capacity of water (4.184 J/g°C)
∆T = change in temperature
From the given information, m = 0.905 g, initial temperature (room temperature) = 21°C , final temperature = 175°C, Q = ?
Q = m × c × ∆T
Q = 0.905 × 4.184 × (175°C - 21°C)
Q = 3.786 × 154
Q = 583.044 Joules
In kilojoules i.e. we divide by 1000, the amount of heat is:
= 583.04/1000
= 0.583 kilojoules
Indicate whether each of the following statements about Joseph Priestley’s experiment is an observation or an inference.
The candle stayed lit longer because the plant gave off oxygen.
The candle went out when it was placed in a closed jar.
The candle stayed lit longer in closed jar when a plant was present.
Answer:
Inference — The candle stayed lit longer because the plant gave off oxygen.
Observation — The candle went out when it was placed in a closed jar.
Observation — The candle stayed lit longer in closed jar when a plant was present.
Explanation:
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(If helpful)
Joseph Priestley discovered the element oxygen which is most precious for living. He discovered the need of oxygen to respire and release by plants during photosynthesis.
What is photosynthesis?Photosynthesis is the process of synthesis of glucose using carbon dioxide and water with the aid of light energy. The process makes energy for all the living organism in earth.
Plants uptake carbon dioxide and release oxygen during photosynthesis which makes oxygen abundant in the atmosphere.Thus, presence of plants give us air and remove carbon dioxide formed by respiration.
Priestley's conducted an experiment with a mouse placed in a closed jar and candle light inside. When the jar is close, there will be no air inside make the rat perish and candle light off. When he placed a plant inside the jar it released oxygen which made the rat alive a little longer.
Candle light stayed a lit longer by the presence of the plant. Thus option A is correct. Priestley concluded that buring needs oxygen.
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Select the pair of compounds that you would expect to form a homogeneous solution based on intermolecular forces. Please choose the correct answer from the following choices, and then select the submit answer button. Answer choices CBr4 and NH3 CCl4 and H2O NH3 and H2O Br2 and HCl
Answer:
NH3 and H2O
Explanation:
In chemistry, the overarching principle of like dissolve like decides the solubility of one substance in another. This principle is ultimately hinged on the idea of intermolecular forces existing between substances. Polar substances dissolve polar substances while nonpolar substances dissolve nonpolar substances in accordance with this principle.
Both NH3 and H2O are polar substances that contain the hydrogen bond. Intermolecular hydrogen bonding interaction accounts for the solubility of NH3 in H20.
A steel tank contains a mixture of Ar and He gases. If the partial pressure of helium in the tank is 1085 mmHg, and the partial pressure of argon is 4867 mmHg, what is the total pressure in the tank (in atm)? Answer as a whole number
Answer:
8 atm
Explanation:
Given data:
Partial pressure of Ar = 4867 mmHg
Partial pressure of He = 1085 mmHg
Total pressure = ?
Solution:
According to Dalton law of partial pressure,
The total pressure inside container is equal to the sum of partial pressures of individual gases present in container.
Mathematical expression:
P(total) = P₁ + P₂ + P₃+ ............+Pₙ
Now we will solve this problem by using this law.
P(total) = P(Ar) + P(He)
P(total) = 4867 mmHg + 1085 mmHg
P(total) = 5952 mmHg
mmHg to atm;
5952 /760 = 7.83 atm
P(total) = 8 atm
15.0 L of an ideal gas at 298 K and 3.36 atm are heated to 383 K with a new pressure of 5.60 atm. What is the new volume in liters
Answer:
[tex]V_2=11.6L[/tex]
Explanation:
Hello!
In this case, since we volume, pressure and temperature which are all changing, we can use the combined ideal gas law to write:
[tex]\frac{P_1V_1}{T_1} =\frac{P_2V_2}{T_2}[/tex]
Thus, since the final volume V2 is required, by solving for it, we write:
[tex]V_2=\frac{P_1V_1T_2}{T_1P_2}[/tex]
In such a way, we plug in the given data to obtain:
[tex]V_2=\frac{3.36atm*15.0L*383K}{298K*5.60atm}\\\\V_2=11.6L[/tex]
Which means that the process compressed the gas.
Best regards.
A sample of carbon dioxide is contained in a 250.0 mL flask at 0.917 atm and 19.3 ∘ C. How many molecules of gas are in the sample?
Answer:
The correct answer is 5.76 x 10²¹ molecules
Explanation:
From the problem, we have the following data:
V= 250.0 mL = 0.25 L
P= 0.917 atm
T= 19.3∘C + 273 = 292.3 K
We can use the ideal gas law to find n (number of moles of gas):
PV= nRT
⇒ n = PV/RT = (0.917 atm x 0.25 L)/(0.082 L.atm/K.mol x 292.3 K) = 9.6 x 10⁻³ mol
We know that 1 mol of any compound is equal to 6.022 x 10²³ molecules of the compound⇒ ratio : 6.022 x 10²³ molecules/1 mol
Thus, we multiply n by the ratio to obtain the number of molecules of gas:
9.6 x 10⁻³ mol x 6.022 x 10²³ molecules/1 mol = 5.76 x 10²¹ molecules
Consider a three-dimensional model of methane as seen here in two dimensions. If we use VSEPR theory to describe the geometry of a methane molecule we say its shape is. A) Linear. B) Tetrahedral. C)Trigonal Planar. D)Trigonal Bipyramidal
Answer:B
Explanation:
Tetrahedral I took the test
Answer:
B is the answer'
Explanation:
critically evaluate the role of human beings in perpetuating climate change
Explanation:
To many people around the world, earth is considered to be a place for human beings to live together as one big family. It provides us shelters, foods, water, and the most beautiful sceneries. Without doubt, we are bound to nature. However because the existence of climate change, which according to scientists is defined as the long term changes over climate including temperature and rainfall, the world would probably end up with devastated ecosystem, extinct wildlife, and most importantly despondent humans. The impact that it has on us is incredibly strong that it affects the system of human lives and wildlife. Global warming, precipitating weather, glaciers, and rising of sea level are no more phenom
What information would you need to determine the most likely resonance structure for the molecule?
A. The formal charge of each atom
B. The polarity of each covalent bond
C. The Lewis structure of the molecule
D. The bond length of each covalent bond
Answer:
The Formal Charge of Each Atom
Explanation:
I just took the test!
Answer:
A. The formal charge of each atom
Explanation:
30.1 grams of ice at -250^oC would be required how many kj to increase it's temperature to 15.0^ᴏC
Answer:
16.1923 kj
Explanation:
Given data:
Mass of ice = 30.1 g
Initial temperature = -250 °C
Final temperature = 15.0 °C
Energy required = ?
Solution:
Specific heat capacity of ice is 2.03 J/g.°C
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 15.0°C - (-250 °C)
ΔT = 265°C
Q = 30.1 g × 2.03 J/g.°C × 265°C
Q = 16192.3 J
J to kJ:
16192.3 J × 1 KJ /1000 j
16.1923 kj
A photovoltaic cell converts light into electrical energy. Suppose a certain photovoltaic cell is only 63.5% efficient, in other words, that 63.5% of the light energy is ultimately recovered. If the energy output of this cell is used to heat water, how many 520 nm photons must be absorbed by the photovoltaic cell in order to heat 10.0 g of water from 20.0°C to 30.0°?
Answer:: A photovoltaic cell converts light into electrical energy. Suppose a certain photovoltaic cell is only 63.5% efficient, in other words, that 63.5% of the light energy is ultimately recovered. If the energy output of this cell is used to heat water, how many 520 nm photons must be absorbed by the photovoltaic cell in order .
Explanation:
Question 10
2 pts
(2 points) What is the molarity of a solution when 25.0 mL of 0.500 M NaCl is diluted to 150.0 mL?
Show your work. No work = no credit.
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Answer:
M₂ = 0.08 M
Explanation:
Given data:
Initial volume = 25.0 mL
Initial molarity = 0.500 M
Final volume = 150.0 mL
Final molarity = ?
Solution:
Formula:
M₁V₁ = M₂V₂
0.500 M × 25.0 mL = M₂ × 150.0 mL
M₂ = 0.500 M × 25.0 mL / 150.0 mL
M₂ = 12.5 M.mL /150.0 mL
M₂ = 0.08 M
a sample of hydrogen gas (h2) is mixed with water vapor (h2o (g)). the make sure has a total pressure of 811 torr, and the water vapor has a partial pressure of 12 torr. how many moles of hydrogen gas are present in a 10.0 l mixture at 298k?
Answer:
[tex]n=0.430molH_2[/tex]
Explanation:
Hello!
In this case, considering the partial Dalton's law of partial pressures, we can notice that the total pressure equals the pressure of steam and the pressure of hydrogen, which can be determined as shown below:
[tex]p_T=p_H+p_w\\\\p_H=811torr-12torr=799torr*\frac{1atm}{760torr}\\\\p_H=1.05atm[/tex]
Thus, by using the ideal gas law, we can compute the moles of hydrogen as shown below:
[tex]PV=nRT\\\\n= \frac{PV}{RT}=\frac{1.05atm*10.0L}{0.082\frac{atm*L}{mol*K}*298K}\\\\n=0.430molH_2[/tex]
Best regards!
The equilibrium constant, Kc, for the following
reaction is 10.5 at 350 K.
2CH2Cl2(g) double arrow CH4(g) + CCl4(g)
If an equilibrium mixture of the three gases in a 12.7
L container at 350 K contains 0.205 mol of
CH2Cl2(g) and 0.414 mol of CH4, the equilibrium
concentration of CCl4 is......
mol.
Answer:
2CH2Cl2(g) Doublearrow CH4(g) + CCl4(g)
0.205 moles of CH2Cl2 is introduced. Let by the time an equilibrium is reached x moles each of CH4 and CCl4 are formed => remaining moles of CH2Cl2 are 0.205-x
i.e at equilibrium the concentration on CH2Cl2 is (0.205-2x) mol/L, CH4 is x mol/L, CCl4 is x mol/L
Now the equilibrium constant equation : K = [CH4][CCl4]/[CH2Cl2]^2 ([.] - stands for concentration of the term inside the bracket)
10.5 = x*x/(0.205-2x)^2
=> 10.5(4x^2-0.82x+0.042) = x^2
=>42x^2-8.61x+0.441=x^2
=>41x^2-8.61x+0.441 = 0
This is a Quadratic in x, solving for the roots, we get x = 0.0886 , x = 0.121
The second solution for x will lead 0.205-2x to become negative, so is an infeasible solution.
Therefore equilibrium concentrations of the products and reactants correspond to x=0.0886 and they are , [CH2Cl2] = 0.205-2*0.0886 =0.0278 mol/L , [CH4] = 0.0886 mol/L , [CCl4] = 0.0886 mol/L
A geneticist has discovered a new compound that is made up of a small number of identical
subunits. The subunits are joined end to end in long chains. Based on this information, what
best can be concluded about these subunits?
A. They are ketones.
B. They are hydrocarbons.
C. They are monomers.
D. They are polymers.
Answer:
They are monomers.
Explanation:
Edg 2020
Answer:
C.monomers
Explanation:
edg. 2020 read and use common sense
Which EMW can humans see?
Answer:
visible light waves are the only electromagnetic waves we can see
If 6.81 mol of an ideal gas has a pressure of 2.99 atm and a volume of 94.35 L, what is the temperature of the sample?
Answer:
504.57 K.
Explanation:
From the question given above, the following data were obtained:
Number of mole (n) = 6.81 moles
Pressure (P) = 2.99 atm
Volume (V) = 94.35 L
Gas constant (R) = 0.0821 atm.L/Kmol
Temperature (T) =.?
Using the ideal gas equation, the temperature of the ideal gas can be obtained as follow:
PV = nRT
2.99 × 94.35 = 6.81 × 0.0821 × T
282.1065 = 0.559101 × T
Divide both side by 0.559101
T = 282.1065 / 0.559101
T = 504.57 K.
Thus, the temperature of the ideal gas is 504.57 K.
Identify the correct order of electron transfers in the electron transport chain starting from FADH2.
Answer:
FADH₂ → Q coenzyme → Complex III → c cytochrome → Complex IV → O₂
Explanation:
During oxidative phosphorylation, the electrons from NADH and FADH₂ are combined with O₂ and the energy released in the process is used to synthesize ATP from ADP.
The components of the electron transport chain are located in the internal part of the mitochondrial membrane in eukaryotic cells, and in the cell membrane in bacteria. The transporters in the electron transport chain are organized into four complexes in the inner mitochondrial membrane. A fifth complex then couples these reactions to the ATP synthesis.
Complex II receives the electrons from the succinate, which is an intermediary in the Krebs cycle. These electrons are transferred to the FADH₂ and then to the Q coenzyme. This liposoluble molecule will transport the electrons from Complex II to Complex III. In this complex, the electrons are transferred from the b cytochrome to the c cytochrome. This c cytochrome, which is a peripheric membrane protein located in the external part of the inner membrane, then transports the electrons to Complex IV where finally they are transferred to the oxygen.
A mass scale reads 10 kilograms on earth, what would it read on the moon?
Write a balanced molecular equation (photo)
Answer:
Ba + 2HCl = BaCl₂ + H₂
Explanation:
The equation for Magnesiunm's reaction with hydrochloric acid is
Mg + 2HCl = MgCl₂ + H₂
So, just replace magnesium in the equation above and you get the equation for barium's reaction with hydrochloric acid.
Identify which of the following equations are balanced.A. 6Li(s)+N2(g)→2Li3N(s)6Li(s)+N2(g)→2Li3N(s).B. 2KMnO4(s)→K2MnO4(s)+MnO2(s)+O2(g). C. 2KClO3(s)→2KCl(s)+O2(g)2KClO3(s)→2KCl(s)+O2(g). D. Mg(s)+N2(g)→Mg3N2(s)Mg(s)+N2(g)→Mg3N2(s).
Answer:
love u baby doll thanks for the help
The graph shows the distance an object travel in 11 seconds which answer choice best describes the movement of the object between the times of 0 and 6 seconds on the graph
Answer:
its moving at a constant speed
Explanation:
i did the test and got it right
Use the periodic table to match each of the following element symbols to its name, atomic mass, or atomic number. (3 points)
1.
Se
2.
S
3.
Sn
a.
Tin
b.
78.971 u (atomic mass)
c.
16 (atomic number)
Answer:
Tin I thunk
Explanation:
I think
Answer:
sn = tin
se = 78.971 u (atomic mass)
s = 16 (atomic number)
URGENT:
(I’ll give first person brainlyist)
What type of elements typically become positively charged ions?
Answer:
The elements that are commonly positive ions are metals. But there are a few gases that can become positively charged by losing electrons.
Typically, when metals and non-metals interact, the metals' electrons are transferred to the non-metals. In contrast to non-metals, which form negatively charged ions, metals form positively charged ions.
The non-metal picks up electrons and gets negatively charged, whereas the metal loses electrons and gets positively charged. Cations and anions are the names given to positively and negatively charged ions, respectively.
Metals are the elements that lose electrons to generate positively charged ions (cations) in all chemical processes, with the exception of hydrogen. Metals are electropositive elements as a result.
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