Answer:
ΔH = 46.2 kJ
Explanation:
Hello there!
In this case, according to the given set of reactions and the required one, it is possible to apply the Hess' rule in order to realize the following manipulations to obtain the required reaction:
1. Keep this reaction as it is.
2Fe(s) + O2(g) => 2FeO(s) ΔH = -545.6 kJ
2. Keep this reaction as it is.
4Fe(s) + 3O2(g) => 2Fe2O3(s) ΔH = -1,643.6 kJ
3. Reverse double this reaction so that we obtain:
2Fe3O4(s) => 6Fe(s) + 4O2(g) ΔH = -(-1,117.7 kJ)*2=2235.4kJ
Add them up to obtain:
2Fe(s) + O2(g) + 4Fe(s) + 3O2(g) + 2Fe3O4(s) => 6Fe(s) + 4O2(g) +2Fe2O3(s) + 2FeO(s)
Simplify common terms to obtain:
2 Fe3O4(s) => 2 Fe2O3(s) + 2 FeO(s)
Therefore, the enthalpy of such reaction is:
ΔH = 2235.4kJ -545.6 kJ -1,643.6 kJ
ΔH = 46.2 kJ
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Classify the following alcohol as primary,
secondary or tertiary.
OH
A. primary
B. secondary
C. tertiary
Answer:
The correct answer is C, tertiary.
The following alcohol is a tertiary alcohol. Hence, option C is correct.
What is primary alcohol?A primary alcohol is a compound in which a hydroxy group, ‒OH, is attached to a saturated carbon atom which has either three hydrogen atoms attached to it or only one other carbon atom and two hydrogen atoms attached to it.
Here, the carbon atom holding the OH group is attached directly to three alkyl groups.
Hence, the following alcohol is a tertiary alcohol.
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An ideal gas in a sealed container has an initial volume of 2.80 L. At constant pressure, it is cooled to 18.00 °C, where its
final volume is 1.75 L. What was the initial temperature?
Answer:
[tex]T_1=-91.18\°C[/tex]
Explanation:
Hello there!
In this case, given the T-V variation, we understand it is possible to apply the Charles' law as shown below:
[tex]\frac{T_1}{V_1}= \frac{T_2}{V_2}[/tex]
Thus, since we are interested in the initial temperature, we can solve for T1, plug in the volumes and use T2 in kelvins:
[tex]T_1= \frac{T_2V_1}{V_2}\\\\T_1= \frac{(18.00+273.15)K(1.75L)}{(2.80L)}\\\\T_1=182K-273.15\\\\T_1=-91.18\°C[/tex]
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How many moles of solute are in 53.1 mL of 12.5M HCI?
Atoms are the smallest unit of an element that holds the physical identity of that element. T or F
Answer:
True
Explanation:
Which object will have more potential energy (PE), a book on the edge of a small bookshelf or a penny sitting on the edge of the Empire State building? EXPLAIN your reasoning.
Answer: I dont know
Explanation: figure it out
what type of forces are unequal forces that cause a change in an object's motion such as speed or direction
Answer:
Unbalanced forces are not equal, and they always cause the motion of an object to change the speed and/or direction that it is moving.
Explanation:
When two unbalanced forces are exerted in opposite directions, their combined force is equal to the difference between the two forces.
The magnitude and direction of the net force affects the resulting motion
This combined force is exerted in the direction of the larger force
For example, if two students push on opposite sides of a box sitting on the floor, the student on the left pushes with less force (small arrow) on the box than the student on the right side of the box (long arrow).
The resulting action (net force: smaller arrow to the right of the = shows that the box will change its motion in the direction of the greater force
If unbalanced forces are exerted in the same direction, the resulting force (net force) will be the sum of the forces in the direction the forces are applied.
When forces act in the same direction, their forces are added. When forces act in opposite directions, their forces are subtracted from each other.
Unbalanced forces also cause a nonmoving object to change its motion
If there is no net force acting on the object, the motion does not change. If there is a net force acting on an object, the speed of the object will change in the direction of the net force.
PLEASE HELP
How many chlorine atoms are needed to satisfy the octet rule when forming an ionic compound with a cation of charge 3+?
Answer:
not the right answer but I need this for the answer the question thing
What is the precipitation like in the arctic tundra?
Use this website to answer the question: https://thewildclassroom.com/biomes/artictundra-2/
Question 4 options:
In summer, it typically rains less than 5 cm (<2 inches), while in winter it rains 25–44 cm (10–17 inches).
There is an average of 20 – 35 inches of rainfall a year.
The range is from 15-25cm (6-10 inches) a year where most falls as snow.
It can can also be called a cold desert due to its lack of precipitation.
Answer:
In summer, it typically rains less than 5 cm (<2 inches), while in winter it rains 25–44 cm (10–17 inches).
Explanation:
because tundra vegetation is mostly found in desert areas
what do protons determine about an element
Answer:
The number of protons in one atom of an element determines the atom's identity, and the number of electrons determines its electrical charge. The atomic number tells you the number of protons in one atom of an element. It also tells you the number of electrons in a neutral atom of that element.
Explanation:
Which organism dna will differ the most from the leopard
Answer:
Lancelet
Explanation:
This is because a Lancelet is a small elongated marine invertebrate that lacks all of the physiological and biological traits of a leopard
There are 3 gases in a container, methane has a partial pressure of 1.23 atm, ethane's partial pressure is 1.48 atm and an unknown pressure of propane. The pressure in the container was measure to be 4.43 atm. What is the partial pressure of propane?
A) 1.72
B) 1.35
C) 1.69
D) 1.53
Answer:
A) 1.72 atm
Explanation:
Dalton's Law of Partial Pressures
[tex]P_{t} = P_{1} + P_{2} + P_{3} ....[/tex]
4.43 atm = 1.23 atm + 1.48 atm + x
x = 4.43 atm - (1.23 atm + 1.48 atm)
x = 1.72 atm
Is carbonic acid (H2CO3) soluble in water?
Answer:
it is soluble in water
Explanation:
mark brainliest pliiz cutee:)
How is gravity an attractive force?
how many atoms of carbon are in a diamond with a mass of 0.568 g?
Answer:
There are 2.85 x 10^22 atoms of carbon in a diamond with a mass of 0.568 g.
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Sally rides her bike to the store to get some Skittles. The store is 5 km
away. If it takes her 10 minutes to get to the store what is her average
speed?
0.5 km/hr
0.5 mph
0.5 km/min
5 km/min
Answer:
Sally's average speed is 0.5 km/min
Explanation:
speed=distance/time
so, 5km/10min=0.5 km/min
James made a poster showing the two body systems that regulate a person's pulse. Which two systems did james represent on his poster? F nervous and circulatory G resiratoty and endocrine systems H circular and digestive system I digestive and nervous system
Answer:
F
Explanation:
> Question 20 3.3 pts A gas occupies 500.0 mL at a temperature of 27.0°C. What is the volume at 15.0°C? (Remember to convert °C to Kelvin.) Use Charles' Law V1T2 = V2T1 © 1500 O 480 0 350 900
Answer:
480.0 mL
Explanation:
Step 1: Given data
Initial volume (V₁): 500.0 mLInitial temperature (T₁): 27.0 °CFinal volume (V₂): ?Final temperature (T₂): 15.0 °CStep 2: Convert the temperatures to the Kelvin scale
We will use the following expression.
K = °C + 273.15
K = 27.0°C + 273.15 = 300.2 K
K = 15.0°C + 273.15 = 288.2 K
Step 3: Calculate the final volume
Assuming ideal behavior and constant pressure, we can calculate the final volume using Charles' law.
V₁ × T₂ = V₂ × T₁
V₂ = V₁ × T₂ / T₁
V₂ = 500.0 mL × 288.2 K / 300.2 K = 480.0 mL
Meat-eating animals are:
decomposers
second-order consumers
producers
first-order consumers
HELP
Answer:
decomposers
Explanation:
USA test prep wave 1 performance task
Answer:
Performance Tasks 188; Instructional Videos 75
Explanation:
In the hydrogenation of ethylene using a nickel catalyst, the initial concentration of ethylene is 1.65 mol⋅L−1 and its rate constant (k) is 0.0014 mol⋅L−1⋅s−1 . Determine the rate of reaction if it follows a zero-order reaction mechanism.
Answer:
.0014 M/s ( (mol*L^-1 / s) )
Explanation:
Since the rate law of a zero order reaction is Rate = k[A]^0, the rate is .0014 * (1.65)^0 = .0014
How many moles of carbon dioxide are produced when 0.25 mole of butane is consumed?
Answer:
1
Explanation:
Let's write the equation first:
[tex]C_{4}H_{10} + \frac{13}{2} O_{2} -> 4 CO_2 +5 H_{2}O[/tex]
So 1 mole of butane reacts to give 4moles of Carbon diOxide.
thus , 0.25 mole of butane will react to give = 4 * 0.25= 1 mole Carbon diOxide
A percent composition analysis yields
22.6% phosphorus (P) and 77.4%
chlorine (CI). What is the empirical
formula for the compound?
А
B
P2C17
PCI:
Answer:
PCl₃
Explanation:
To determine the empirical formula of a compound, we need to follow a series of steps.
Step 1: Divide each percent composition by the atomic mass of the element
P: 22.6/30.97 = 0.729
Cl: 77.4/35.45 = 2.18
Step 2: Divide all the numbers by the smallest one, i.e. 0.729
P: 0.729/0.729 = 1
Cl: 2.18/0.729 ≈ 3
The empirical formula of the compound is PCl₃.
Calculate the number of copper atoms in a 63.55 g
sample of copper.
Answer:
there are N_A, "Avogadro's number" of copper atoms in a 63.55*g mass of copper wire. And N_A, "Avogadro's number" = 6.022xx10^23 individual copper atoms. I look on the Periodic Table, and at Z=29, i.e. copper, the quoted atomic mass is 63.55*g.
Explanation:
One mole of every substance contains 6.022×10²³ atoms. The atomic mass of copper is 63.55 g. Thus it is one mole of copper which contains copper 6.022×10²³ atoms.
What is copper?Copper is 29th element in periodic table. It is a transition metal classified into d-block. Transition metals are named so because they in between the metals and non-metals in periodic table.
Transition metals have varying oxidation state. Copper exists in +1, +2 and +3 oxidation states.
Any substance containing 6.022×10²³ atoms is called one mole of that substance. This number is called Avogadro number. Hence one mole of each element contains avogadro number of its atoms.
Similarly one mole of each compound contains 6.022×10²³ number of molecules. Here, the atomic mass of copper is 63.55 g. That is one mole of copper weighs 63.55 g. Hence, number of atoms in 63.55 g of copper is 6.022×10²³ atoms.
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How many moles would be present in a gas contained in a 100.0 mL vessel at 25.0oC at a pressure of 2.50 atm?
Answer:
n = 0.0102 mol.
Explanation:
Hello there!
In this case, according to the ideal gas law, which allows us to set up a relationship among volume, pressure, temperature and moles, we can define it as:
[tex]PV=nRT[/tex]
Thus, given the volume in liters (0.1000 L), temperature in kelvins (298.15 K) and pressure in atmospheres (2.50 atm), we can solve for moles as shown below:
[tex]n=\frac{PV}{RT}[/tex]
Thereafter, we plug in the aforementioned values to obtain:
[tex]n=\frac{2.50atm*0.1000L}{0.08206\frac{atm*L}{mol*K}*298.15K}\\\\n=0.0102mol[/tex]
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What happens to the amplitude of waves when two waves overlap and are out of phase with each other?
Answer:
Also called superposition. When overlapping waves produce a wave with an amplitude that is the sum of the individual waves. When overlapping waves produce a wave with an amplitude that is less than the sum of the individual waves.
Explanation:
Explain why a city that receives 10 hours more light each day has colder average temperatures. Explain
Explanation:
This would be similar to how the poles work in the North and South. Due to their placement, they recieve much more sun light than the rest of the Earth since we rotate horizontally. However, their placement also makes them farther from the sun than the rest of Earth, therefore not receiving as much heat.
I have to make question longer this question
(Answer the question all the way at the bottom)
\
Do you breathe air?
Answer:
Of course I breathe air.
Explanation:
I'm not a fish.
Answer:
[tex]ummmmmmm \: yes \: [/tex]
A diver takes a balloon with a volume of 2.5Lfrom the surface, where the pressure is 1.0 atm, to a depth of 20m, where the pressure is 3.0 atm. What happen to the volume of the balloon? What if the end of the subnerged balloon is on a long pipe that goes to the surface and is attached to another balloon?
Answer:
The explanation is given below:
Explanation:
As we know that the volume is inversely proportional to the volume. If the pressure is rising from 1 atm to 3 atm so the volume of the ballon would decrease
P_1V_1 = P_2V_2
1.0 × 2.5L = 3 × V_2
V_2 = 0.833L
Since the air is moving from high pressure to low pressure and the two ballons are interconnected via a long pipe so the movement of the air is from bottom to top
Aqueous copper (II) sulfate reacts with aqueous potassium fluoride to produce
a precipitate of copper (II) phosphate and aqueous potassium sulfate.
Answer:
CuSO₄(aq) + 2 KF(aq) = CuF₂ + K₂SO₄
Explanation:
The question is missing but I think it must be about writing and balancing the equation.
Let's consider the unbalanced equation for the reaction that occurs when aqueous copper (II) sulfate reacts with aqueous potassium fluoride to produce a precipitate of copper (II) fluoride (I fixed a mistake here) and aqueous potassium sulfate. This is a double displacement reaction.
CuSO₄(aq) + KF(aq) = CuF₂ + K₂SO₄
Since only K and F atoms are not balanced, we will get the balanced equation by multiplying KF by 2.
CuSO₄(aq) + 2 KF(aq) = CuF₂ + K₂SO₄
Determine the enthalpy of neutralization in Joules/mmol for a solution resulting from 19 mL of 1 M NaOH solution and 19 mL of a HCl with the same molarity. If separately, each had a temperature of 28.6 degrees Celsius, and upon addition, the highest temperature reached by the solution was graphically determined to be 37.3 degrees Celsius. Round to the nearest whole number.
Answer:
[tex]\Delta _{neutralization}H=-73\frac{J}{mmol}[/tex]
Explanation:
Hello there!
In this case, by considering this calorimetry problem, it is possible to realize that the heat released by the reaction between HCl and NaOH is absorbed by the reaction mixture, which can be assumed to have the same density and specific heat of pure water; thus, we calculate this heat as a function of the specified temperature change:
[tex]Q_{rxn}=-Q_{solution}\\\\Q_{rxn}=-m_{solution}C_{solution}(T_2-T_1)[/tex]
Thus, we plug in the data, by also considering that the total volume of solution is 19mL+19mL=38mL:
[tex]Q_{rxn}=-(38mL*\frac{1g}{1mL} )(4.184\frac{J}{g\°C}) (37.3\°C-28.6\°C)\\\\Q_{rxn}=-1383.2J[/tex]
Next, since the reaction between NaOH and HCl is:
[tex]NaOH+HCl\rightarrow NaCl+H_2O[/tex]
Whereas there is 1:1 mole ratio of NaOH to HCl, we infer they both react with the same moles, defined by the volume and molarity:
[tex]n_{rxn}=0.019L*1mol/L\\\\n_{rxn}=0.019mol[/tex]
Finally, to compute the enthalpy of neutralization we divide the total heat due to the reaction by the reaction moles to obtain:
[tex]\Delta _{neutralization}H=\frac{Q_{rxn}}{n_{rxn}=}\\\\ \Delta _{neutralization}H=\frac{-1383.23J}{0.019mol}\\\\\Delta _{neutralization}H=-72801.6\frac{J}{mol}*\frac{1mol}{1000mmol}\\\\\Delta _{neutralization}H=-73\frac{J}{mmol}[/tex]
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