The standard enthalpy change for reaction (3) is 117.1 kJ.
The standard enthalpy change for reaction (3) can be calculated by using the enthalpy changes of reactions (1) and (2) and applying Hess's Law.
To do this, we need to manipulate the given equations so that the desired reaction (3) can be obtained.
First, we reverse reaction (1) to get the formation of C2H4(g) from C2H6(g):
C2H4(g)C2H6(g) ΔH° = -52.3 kJ
Next, we multiply reaction (2) by 2 and reverse it to obtain 2 moles of C2H6(g) reacting to form 3 moles of H2(g):
2C2H6(g)2C(s) + 3H2(g) ΔH° = 169.4 kJ
Now, we add the two modified equations together:
C2H4(g)C2H6(g) ΔH° = -52.3 kJ
2C2H6(g)2C(s) + 3H2(g) ΔH° = 169.4 kJ
When adding these equations, the C2H6(g) on the left side cancels out with the C2H6(g) on the right side, leaving us with the desired reaction (3):
C2H4(g) + H2(g)C2H6(g) ΔH° = -52.3 kJ + 169.4 kJ = 117.1 kJ
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i have a few question please help its due in a few hours
1. Determine the specific heat of a certain metal if a 450 gram sample of it loses 34,500J of heat as its temperature drops by 97K
2. The temperature of a 25 gram sample of a certain metal drops by 103 K as it loses 2600 joules of heat. What is the specific heat of the metal?
3.What is the final temperature after 840 Joules is absorbed by 10.0g of water at 298K?
(please show steps)
Answer:
1 = c = 0.79 j/g.K
2= c = 1 j/g.K
3 = T2 = 123.1 K
Explanation:
Given data:
Specific heat of metal = ?
Mass of metal = 450 g
Heat loses = 34,500 j
Temperature drop = ΔT = 97 K
Solution:
Specific heat capacity:
It is the amount of heat required to raise the temperature of one gram of substance by one degree.
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
34500 j = 450 g ×c × 97 K
34500 j = 43650 g.K ×c
c = 34500 j/43650 g.K
c = 0.79 j/g.K
2)
Given data:
Specific heat of metal = ?
Mass of metal = 25 g
Heat loses = 2600 j
Temperature drop = ΔT = 103 K
Solution:
Specific heat capacity:
It is the amount of heat required to raise the temperature of one gram of substance by one degree.
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
2600 j = 25 g ×c × 103 K
2600 j = 2575 g.K ×c
c = 2600 j/2575 g.K
c = 1 j/g.K
3)
Given data:
Mass of water = 10 g
Heat absorbed = 840 j
Initial temperature drop = 298 K
Final temperature = ?
Solution:
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 = T2 - T1
840 j = 10 g ×4.18 j/g.K × [T2 - 103 K]
840 j = 41.8 J/K × [T2 - 103 K]
840 J/41.8 J/ K = T2 - 103 K
20.1 k = T2 - 103 K
T2 = 20.1 K + 103 K
T2 = 123.1 K
In your own words describe a chemical change and physical change.
Which of these most directly affects what happens to white light when it hits an object?
the properties of the object
the source of the light
the speed at which the light travels
the distance of the object from the light
Answer:
the answer is a is got it right on engdenuity
Explanation:
The fact that most directly affects what happens to white light when it hits an object is the properties of the object.
What is white light?White lighte is that light which conatins all the colors of the vissible spectrum in it.
As a result, the behavior of white light is determined by the qualities of the thing it strikes. When white light strikes an item and all of the light wavelengths are reflected, we see a white color. And if we are able to see any color of an object then because of the fact that given object will reflect only that color and absorb other all.
Hence the properties of the object directly affects the effect of white light.
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Why isn't the atomic mass of most of the elements on the Periodic Table an integer (not a decimal)?
Answer:
Atomic mass is never an integer number for several reasons
1. The radius of a Cl nucleus is 4.0 fm, and the radius of a Cl atom is 100 pm. (1
fm = 1x 10-15 m; 1 pm = 1 x 10-12 m).How many times larger is the diameter
of the Chlorine atom than the diameter of the Chlorine nucleus?
Answer:
The diameter of the Chlorine atom is 25000 times larger than the diameter of the Chlorine nucleus.
Explanation:
From the question,
The radius of a Cl nucleus is 4.0 fm and radius of a Cl atom is 100 pm.
To determine how many times larger the diameter of the Chlorine atom is than the diameter of the Chlorine nucleus,
First, we will determine the diameter of the Chlorine atom and the diameter of the Chlorine nucleus.
(NOTE: Diameter = Radius × 2)
For the Chlorine atom
Radius of the Chlorine atom = 100 pm
∴ Diameter of the Chlorine atom = 2 × 100 pm
Diameter of the Chlorine atom = 200 pm
For the Chlorine nucleus
Radius of Chlorine nucleus = 4.0 fm
∴ Diameter of the Chlorine nucleus= 2 × 4.0 fm
Diameter of the Chlorine nucleus = 8.0 fm
Now, we will convert both diameters ( diameter of Chlorine atom and diameter of Chlorine nucleus) to the same unit
For Chlorine nucleus
Diameter of the Chlorine nucleus = 8.0 fm
If 1 fm = 1 × 10⁻¹⁵ m
Then, diameter of the Chlorine nucleus = 8.0 × 1 × 10⁻¹⁵ m
Diameter of the Chlorine nucleus = 8.0 × 10⁻¹⁵ m
For Chlorine atom
Diameter of the Chlorine atom = 200 pm
If 1 pm = 1 × 10⁻¹² m
Then, diameter of the Chlorine atom = 200 × 1 × 10⁻¹² m
Diameter of the Chlorine atom = 200 × 10⁻¹² m
Diameter of the Chlorine atom = 2 × 10⁻¹⁰ m
Now, to determine how many times larger the diameter of the Chlorine atom is than the diameter of the Chlorine nucleus, we will divide the diameter of the Chlorine atom by the diameter of Chlorine nucleus.
Diameter of Cl atom / Diameter of Cl nucleus = (2 × 10⁻¹⁰ m) / (8.0 × 10⁻¹⁵ m)
(2 × 10⁻¹⁰ m) / (8.0 × 10⁻¹⁵ m) = 25000
∴ Diameter of Cl atom / Diameter of Cl nucleus = 25000
Hence, the diameter of the Chlorine atom is 25000 times larger than the diameter of the Chlorine nucleus.
The diameter of the Cl atom has been 25,000 times larger than the diameter of the Cl nucleus.
To calculate the relationship between the diameter of Cl atom and nucleus, the diameter has to be calculated.
Diameter = 2 [tex]\times[/tex] radius
Diameter of Cl atom:
Cl atom = 2 [tex]\times[/tex] 100 pm
Cl atom = 200pm
1 pm = [tex]\rm 10^-^1^2[/tex] m
200 pm = 200 [tex]\times[/tex] [tex]\rm 10^-^1^2[/tex] m
Diameter of Cl nucleus:
Cl nucleus = 2 [tex]\times[/tex] 4 fm
Cl nucleus = 8 fm
1 fm = [tex]\rm 10^-^1^5[/tex] m
8 fm = 8 [tex]\times[/tex] [tex]\rm 10^-^1^5[/tex] m.
The relationship between the Cl atom and the nucleus has been made by taking the ratio of the diameter of the Cl atom to the Cl nucleus.
[tex]\rm \dfrac{Diameter\;of\;Cl\;atom}{Diameter\;of\;Cl\;nuclues}\;=\;\dfrac{200\;\times\;10^-^1^2}{8\;\times\;10^-^1^5}[/tex]
Diameter of Cl atom = 25000 Diameter of Cl nucleus.
Thus, the diameter of Cl atom has been 25,000 times larger than the diameter of the Cl nucleus.
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Neil is comparing the shifts in light patterns of two distant galaxies. Using a powerful telescope, he records the light shifts of each galaxy every 20 seconds (s) for six hours (hr). After sharing his data with Betty, another astronomer, she says that this is not an experiment.
Which of the following statements supports Betty's claim?
A.The hypothesis is actually the first step in the scientific method.
B.The hypothesis guides the researcher towards the results of the experiment.
C.The hypothesis provides the steps needed to analyze the data to reach conclusions.
D.The hypothesis provides a prediction about what might happen during the experiment.
Answer:c
Explanation: can someone help me to see if this is true
Which of the following is NOT a unit energy? (select all that applies)
Kelvin
Kelvin
calories
calories
Celsius
Celsius
Fahrenheit
Fahrenheit
joules
Answer:
Kelvin, Celsius, Fahrenheit
Explanation:
See my other answer for an explanation.
Joules, Kelvin and Calories
When water boils and becomes steam at around 100 degrees Celsius, this is an example of a
A. Physical change
B. Chemical change
C. Chemical reaction
D. Covalent bond?
How many milligrams are equal to 0.0265 pounds?
(Dimensional Analysis)
Please show how you got that answer.
Answer:
37.73 pounds
Explanation:
just trust me.
what is the metal that is grouped with metalloids
Answer:
The post-transition metals cluster to the lower left of this line. Metalloids: The metalloids are boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te) and polonium (Po). They form the staircase that represents the gradual transition from metals to nonmetals.
Explanation: i googled it
The metal that is grouped with metalloids are
boron, silicon, germanium,arsenic, antimony, and tellurium.A metalloid is a type of element which possesses the characteristics of both the metals and the non-metals.
Metals are those elements that are good conductors of heat and electricity while non-metals are those elements that neither conducts heat nor electricity.
The characteristics of the metalloids listed above are:
They conduct heat only at higher temperatures. The metalloids that can conduct electricity are called semi-conductors.They are shiny like metals but brittle like non-metals.Therefore, since these elements share both the properties of metals and non-metals, they are called the metalloids.
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Which element has 4 energy levels and 2 valence electrons?
Answer:
Beryllium
Explanation:
The element that has 4 energy levels and 2 valence electrons is Beryllium.
What is a Beryllium?Beryllium is a chemical element that comes in the second row and is an alkaline earth metal.
It is silvery-white, and very brittle at room temperature.
Its properties are similar to aluminum.
It has two valence electrons in the k shell and two in L shell.
Thus, the correct element is Beryllium.
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How many total atoms in the compound Al3NO2
Answer:
1 mole of aluminum must contain 6.022⋅1023 atoms of aluminium → this is known as Avogadro's constant.
Explanation:
Answer:
[tex]6.02 \times {10}^{23} \: atoms[/tex]
Explanation:
since every compound is equivalent to one mole of particles. This number is represented by avagadros constant which represents the atomic proportion from molar to physical mass on a human scale. This equates to the amount of particles per mole of substance(amount of substance).
[tex]6.02 \times {10}^{23} \: {mol}^{ - 1} [/tex]
this can be denoted in symbol form by
[tex]N_A[/tex]
avagadros constant is defined as rational so the exact value is 6.02214076×10^23.
avagadros number : 1 mole
Determine the number of atoms in the following chemical formula: Ba(OH)2
Answer:
5
Explanation:
Ba,1 O,2 H,2
the somes are 5
Based on the tiles shown, how many meters per second is equivalent to 72 kilometers per hour?
Answer:
10 kilometers per hour
Explanation:
How many valence electrons will atoms in group 16 of the periodic table have?
Answer:
6 valence electrons
Explanation:
is this correct im so confused.
Answer:
the last option!!!!
Explanation:
because its right
Most of an atom consists of empty space. Its mass is concentrated in its center, which is called the
nucleus. The nucleus consists of protons and neutrons. (The ordinary hydrogen atom is an
exception; it contains one proton but no neutrons.) Protons carry a positive electrical charge, while
neutrons carry no electrical charge. Circling the nucleus is a cloud of negatively charged electrons.
Answer:
Most of an atom consists of empty space. Its mass is concentrated in its center, which is called the nucleus. The nucleus consists of protons and neutrons.
Explanation:
One example of a chemical change is
A sound wave is traveling at 331 m/s and has a frequency of 126 Hz. What is the wavelength?
2.626984127 m
Explanation:You have to know the equation that relates wavelength, frequency, and velocity (it's like speed but a bit different).
v = f x λ
where:
v = velocity
f = frequency
λ = Wavelength
Rearrange to make λ subject:
λ = v / f
We've been given 331 as the speed, 126 as the frequency. Sub it into the equation:
331 / 126 = 2.626984127 m
5. (04.03 LC)
Which of the following steps can be used to identify an acid-base reaction
Check if one element replaces another element in a compound.
Check if the ions of two compounds exchange places.
O Check whether the reactants are an acid and a base.
Check whether the products are an acid and a base.
Plz help
Answer: Check whether the reactants are an acid and a base.
Explanation:
The step to determine the acid-base reaction, it has been checked that where there has been an acid or base in the reactants or not. Thus, option C is correct.
The acid base reaction can be described as the chemical reaction involving the exchange of hydrogen ions in between the reactant species.
The acid base reaction has been mediated in the system where there has been the presence of an acid or base as the reactant in order to accept or donate hydrogen ions.
Thus, to determine the acid-base reaction, it has been checked that where there has been an acid or base in the reactants or not. Thus, option C is correct.
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The only thing Keith Rodriguez controls in his hot air balloon is altitude. How does he control the balloons altitude?
what is the mass number of an element with an atomic number 10 and 10 neutrons
Answer:
Neon
Explanation:
hskamamsahaksnavshaiaaa
irieiwkaaj
How many sig. figs. are in the following numbers?
1) -16
5) 10,000
2) 5.000 x 1011
6) 2060
3) 0.009090
7) 3.50 x 10-5
4) 4,010
8) 80.011
9) 97.0
10) 0.0010
11) 46.074
12) 0.6
Answer:
1. 2
2. 1
3. 1
4. 3
5. 3
6. 2
7. 3
8. 1
9. 2
10. 1
11. 3
12. 1
Explanation:
There are 3 main significant figure rules, I suggest looking them up online to confirm these answers
in a plant,root cells are different from leaf cells because they have no ?
Answer:
Answer. As a leaf cell is a plant cell contains chloroplasts for photosynthesis which the root hair cell does not have, leaf cell also contains larger vacuoles and the presence of a cell wall.
Explanation:
The atmospheric pressure on a mountain is 500 mmHg and 1 atm is equal to 760 mmHg. What is the pressure in atm?
Answer:
≈ 0.6579 atm
Explanation:
The pressure in atmospheres is the ratio of the pressure on the mountain to one atmosphere, in corresponding units.
The pressure is ...
500 /760 atm = 25/38 atm ≈ 0.6579 atm
how many molecules are contained in 0.254 moles of diarsenic trioxide
Answer:
1.53 × 10²³ molecules As₂O₃
Explanation:
Step 1: Define
Diarsenic Trioxide - As₂O₃
Avagadro's number: 6.02 × 10²³ atoms, molecules, formula units, etc.
Step 2: Use Dimensional Analysis
[tex]0.254 \hspace{3} mol \hspace{3} As_2O_3(\frac{6.02(10)^{23} \hspace{3} molecules \hspace{3} As_2O_3}{1 \hspace{3} mol \hspace{3} As_2O_3} )[/tex] = 1.52908 × 10²³ molecules As₂O₃
Step 3: Simplify
We have 3 sig figs.
1.52908 × 10²³ molecules As₂O₃ ≈ 1.53 × 10²³ molecules As₂O₃
Ions bonds are strong?
True or False
Answer:
Ture
Explanation:
Answer:
true
Explanation:
ions bond are those bonds which are made with the exchange of electrons between metals and nonmetals.Thus they are very strong.
Can someone help me please
Answer:
Strange question. All the answers are D
Explanation:
I don't exactly know how you should answer this. I can find the charge on Chromium. The only hope is that they are all the same.
[Cr(OH)_-6]^-3
x - 6 = -3 Add 6
x = -3 + 6
x = 3
======
CrO4 ^-2
x - 4*2 = - 2 add 8
x = -2 + 8
x = 6
================
Water has no effect on the charge. The chromium has a charge of +2
The density of an object is .835 g/cm3. If its volume is 34 cm3, what is the mass of the object? (Density: D = m/v)
Answer:
The answer is 28.39 gExplanation:
The mass of a substance when given the density and volume can be found by using the formula
mass = Density × volumeFrom the question we have
mass = 0.835 × 34
We have the final answer as
28.39 gHope this helps you
Which particles can be found in the nucleus of an atom?
-protons and neutrons
-protons and electrons
-alpha particles
-neutrons and electrons
Answer:
proteins and neutron.
Answer:
A
Explanation:
