This problem is providing us with the enthalpy of formation of Fe2O3 (s) and the enthalpy of reaction when it reacts with Al to form Al2O3 (s) and Fe. Thus, the enthalpy of formation of Al2O3 (s) is required and found to be -1675.7 kJ/mol as follows.
Enthalpy of reaction.In chemistry, the heat involved in a chemical process can be quantified via the difference in the overall enthalpy of products minus that of reactants:
[tex]\Delta H_r=\Delta H_{products}-\Delta H_{reactants}[/tex]
Now, with the given reaction:
[tex]Fe_2O_3 (s) + 2 Al (s) \rightarrow 2 Fe (s) + Al_2O_3 (s)[/tex]
One can see both Al and Fe have zero as their enthalpies of formation for they are elements. In such a way, one can rearrange the previous formula as:
[tex]\Delta H_r=\Delta H_{Al_2O_3}-\Delta H_{Fe_2O_3}[/tex]
And hence plug in the given energies in order to find the required:
[tex]-851.5kJ/mol=\Delta H_{Al_2O_3}-(-824.2kJ/mol)\\\\\Delta H_{Al_2O_3}=-851.5kJ/mol+(-824.2kJ/mol)\\\\\Delta H_{Al_2O_3}=-1675.7kJ/mol[/tex]
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Which of the following is an example of an ionic compound?
A.) Carbon Dioxide
B.) Oxygen
C.) Sodium Chloride
D.) Water
Answer:
C.) Sodium Chloride
Explanation:
Table salt is an example of an ionic compound. Sodium and chlorine ions come together to form sodium chloride or NaCl.
Find the percent composition of water in barium chloride dihydrate. Round your answer to the
nearest whole number.
A)17%
B)8%
C)85.3%
The percent composition of water will be 15%
Percent compositionThe percent composition of a component of a compound is found by dividing the mass of the component by the mass of the compound.
In other words:
Percent composition = mass of component/mass of substance x 100
In this case, the formula for barium chloride dihydrate is [tex]BaCl_2.H_4O_2[/tex]
The molar mass of the compound is 244.26 g/mol
The molar mass of the water component is 18 x 2 = 36 g/mol
Thus, the percent composition of water in the compound can be found, such that:
Percent composition of water = 36/244.26 x 100
= 15% to the nearest whole number.
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Why NH2 is a bad leaving Group?
Explanation:
Consider that strong bases are strong nucleophiles, and thus unstable with the negative charge associated with dissociation from the molecule. Hence, strong bases are generally very poor leaving groups, but can be converted into good leaving groups that are more stable with the associated negative charge.
Write the pressure equilibrium constant expression for the reaction N2(g)+3H2(g)=2NH3(g)
Answer:
[tex]keq=\frac{[NH_{3} ]^2}{[N_{2} ][H_{2} ]^3}[/tex]
Explanation:
Someone can help me please??
Answer:
c-d
Explanation:
this is a section of the graph sloping down, meaning the state of matter isn't changing but is getting ready too (the actually changing of states happens in the flat sections). A-B is the gas cooling, b-c is the gas changing into liquid, which leads to the liquid cooling in the next section
Part B
The image models what happened after each cup was placed over an effervescent tablet. Note the changes in the water level and the air space in both glasses. The tablets are shown to help see how the experiment was setup, but the model represents the air bubbles after the tablets fully dissolved. Write down your observations in the space provided.
Answer:
The Changes I see is the Hot glass have less air bubbles than the Cold Glass. The Cold Glass has more air bubbles than the Hot Glass.
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Determine the molar mass of (show your work) :
FeCl3•6H2O (note, this is all 1 molecule. Its an FeCl3 with a cage of 6H2O’s attached. These molecules are known as hydrates.)
Ca3(PO4)2
Why does a gas smell diffuse faster than a colour in a liquid?
Answer:
because there are other particles to help it move around in the air
An enzyme-catalyzed reaction is run, and its Vmax and KM value are recorded. An inhibitor is added at a concentration of 0.675 mM. The value for KM did not change between the two reactions. However, Vmax decreased by 70%.
a. Where does this inhibitor bind to the enzyme? Briefly explain.
b. What is the value of Ki for the inhibited reaction?
We have that the value of Ki for the inhibited reaction
The place the enzyme inhibitor binds solely to the complicated fashioned between the enzyme and the substrate.KI = 3.551mMChemical Reactiona)
Generally, if the fee of Vmax binds, the place the enzyme inhibitor binds solely to the complicated fashioned between the enzyme and the substrate.
b) V diminished through 70%
Thereofore
Alternate = 1 - 0.7 = 0.3V
Hence
0.3 =1/ ( 1 + [I]/KI)
1= 0.3(1 + 0.657/KI )
0.3 + 0.1971KI = 1
KI = 3.551mM
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Which of the following circuits is built correctly?
Answer:
number 2 becaus 1 and 3 look simler.
Explanation:
A WATER WAY CONTAINS 10.3 MILIGRAMS OF IMPURITY PER GALLON OF WATER.HOW MANY MICROGRAMS OF IMPURITY ARE PRESENT PER LITER OF WATER.
1 MG= 1000 MICROGRAMS
1 GAL=3.79 LITERS
I Gallon = 3.785 L 1 Mg = 1 mg gallon 3.785L. 3. The recommended adult dose of Elixophyllin®, a drug used to treat asthma, is 6.00 mg/kg of body mass. Calculate the dose in milligrams for a 112 lb person. (o oo Kg | K9 6.oong 112 15 = 3 04.7 - 3 2.20515 2.20516 my k.
Hope this answer will help you.
Compared to protons, electrons have:
a. much smaller mass and oppisite charge.
b. about the same mass and opposite charge.
c. much larger mass and the same charge.
d. much larger mass and oppisite charge.
Explanation:
a. much smaller mass and oppisite charge.
g A student performs an experiment where gas is collected over water in an upside down graduated cylinder. If the atmospheric pressure is 739 mmHg and the level of water in the graduated cylinder is 11 cm higher than the level of the water exposed to the atmosphere, what is the total pressure of gases inside the graduated cylinder
The total pressure of gases is equivalent to 739mmH divided by the area.
How to calculate the total pressure of gases?To calculate the total pressure of gases, the next formula can be used:
Total pressure: Force/areaTotal pressure 739 mmH/areaHow to calculate the area?The area of a cylinder is equal to 2πrh+2πr².
You can know the radio by checking the measurement of the base of the graduated cylinder. Also, you can determine the height by observing how many mm the gas is occupying. Then follow these steps:
Find out the area based on the formula provided.Replace the area in the pressure formula.Solve the formula.Note: This question is incomplete because the height occupied by the gas and the radio of the cylinder are not provided. Due to this, I answered this question based on general knowledge.
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vanadium hydroxide ionic or covalent?
Answer:
Vanadium in given compound is metal and oxygen is non-metal so, the given compound is a binary ionic compound.
1. You have 4.0 g of NaCl. Calculate the number of moles of
NaCl
Answer:
0.07mol
Explanation:
n=mass/molar mass
molar mass of NaCl=23+35.558.5g/moln=4/58.50.07molHow can we explain the motion of objects?
In one or two sentences, explain why the combined weight of several liquids mixed in an open flask can be less than but never more than the sum of all the weights of the ingredients.
Answer:
The combined weights of several liquids mixed in an open flask be less than the sum of all the weights of the liquids because when the reaction occurs new products are formed and also some gases which releases in the atmosphere.
Emi wants to see if she can melt a marshmallow in the sun. She plans to put the marshmallow in a container that will cause it to heat up quickly. In one or two sentences, describe what type of container and materials Emi should use.
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Answer:
emi should put it in a metal container and place directly to the sun emi should place two mirrors opposite it and that will increase the heat which will melt the Marsh mallow
How much H is need to react with 6.58 g of O, in this reaction?
H2 + O2 -> H2O
Answer:
Balance the equation first
[tex]2H_{2} \ + \ O_{2} \ --> \ 2H_{2}O[/tex]
6.58g of Oxygen gas
Divide 6.58g by molar mass of oxygen (32g/mol)
6.58/32 = 0.205625 mol
Use mol to mol ratio from looking at the coefficients of the reactants, the mol ratio of Hydrogen gas to Oxygen gas is 2:1, so for every 1 mol of Oxygen, you need 2 times the mol of hydrogen for it to make water.
0.205625 * 2 = 0.41125 mol
To get the mass of hydrogen gas needed in the reaction, turn 0.41125 mol into mass by multiplying it with Hydrogen gas's molar mass, which is 2.02 g/mol.
0.41125 * 2.02 ≈ 0.83g of H2
how many mL are in 0.0543L
Answer:
Multiply 0.0543 L by a 1000 to get to mL, move the decimal point 3 times to the right, and you get 54.3 mL
How do you separate and collect salt and water after a neutralisation reaction?
Answer:
First filter the the un-soluble solute out of the solution
Then get the solute and put it on an evaporating dish to form salt crystals
Explanation:
A car engine has a displacement of 536 cubic inches (in^3). What is the engines displacement in nm^3? Use dimensional analysis and show all work
The engine displacement in cubic nanometer (nm³) is 8.785×10²⁴ nm³
Data obtained from the question Displacement in in³ = 536 in³Displacement in nm³ =? Conversion scale1 in³ = 1.639×10²² nm³
With the above convesion scale we can obtain the displacement in nm³
How to determine the displacement in nm³1 in³ = 1.639×10²² nm³
Therefore,
536 in³ = 536 × 1.639×10²²
536 in³ = 8.785×10²⁴ nm³
Thus, the displacement in nm³ is 8.785×10²⁴ nm³
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how many grams of k2co3 are needed to make 255 ml of a 88.5 m solution
Answer: You need approximately 70 g of potassium carbonate.
Explanation:
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What pressure is requred to contain 0.023 moles of nitrogen gas in a 4.2 L container at a
temperature of 20.°C?
Answer:
0.13 atm
Explanation:
Using the Ideal Gas Law; PV=nRT, we can rearrange to solve for pressure.
P=nRT/V
P is pressure, n is number of moles (0.023), R is a constant (0.08206 L*atm/mol*K), T is temperature in Kelvin (293.15K) and V is volume, 4.2 L.
So, plugging in;
P=(0.023mol)(0.08206L*atm/mol*K)(293.15K)/(4.2 L)
P=0.1317 atm
P=0.13 atm; multiply by 760 to get to Torr or mmHg.
Describe how the flow of water changes the temperature at the beach ?
Answer: Ocean currents act as conveyer belts of warm and cold water, sending heat toward the polar regions and helping tropical areas cool off
Explanation: Hope this helps? Brainliest if it helped
Write 1/5 as an equivalent fraction with 500 in the denominator?
I need help please
Answer:
100 / 500
Explanation:
100 / 500 is equivalent to 1 / 5.
The Lewis structure below represents the compound ___________________.
Group of answer choices
dioxygen carbide
carbon tetraoxide
carbon dioxide
carbon monoxide
Answer:
Carbon Dioxide
Explanation:
This is a covalent compound so to name it you have one carbon, no prefix needed, & 2 oxygen the prefix for 2 is Di-.
Someone can help me please??
Answer:
first option - liquid particles gain kinetic energy and start moving faster around each other
Explanation:
this is a rising section of the graph, meaning that the state of matter is not changing but it warming up and increasing particle movement. This increase in movement is explained by the increase in kinetic energy. (when the kinetic energy rises, the movement rises)
How do you separate and collect salt and water after a neutralisation reaction?
Explanation:
water can be separated from salt solution by simple distillation. This method works because water has a much lower boiling point than salt. When the solution is heated, the water evaporates. It is then cooled and condensed into a separate container.
How many hydrogen atoms are there in 2.25 moles of H2CO3?
Answer:
4.5moles
Explanation:
2.25moles times 2 hydrogen atoms per one molecule
The number of hydrogen atoms present in 2.25 moles of hydrogen carbonate is 4.5.
What is a mole?
A mole of a compound is equivalent to the one formula unit of the compound. The number of atoms of each element in a mole of the compound can be given from the formula unit.
1 unit of hydrogen carbonate consists of 2 atoms of hydrogen. Thus, 1 mole of hydrogen carbonate has 2 hydrogen atoms.
The number of hydrogen atoms in 2.25 mole of hydrogen carbonate can be given as:
[tex]\rm 1\;mol\;H_2CO_3=2\;atoms\;Hydrogen\\2.25\;mol\;H_2CO_3=2.25\;\times\;2\;atoms\;of\;hydrogen\\2.25\;mol\;H_2CO_3=4.5\;atoms \;of\;Hydrogen[/tex]
The number of hydrogen atoms present in 2.25 moles of hydrogen carbonate is 4.5.
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