In the reaction MgCl2 + 2KOH Mg(OH)2 + 2KCl, if 6 moles MgCl2 are added to 6 moles KOH, which is the limiting reagent?
Answers
Answer: KOH
Explanation:I JUST TOOK IT
Related Questions
Why does iron not fit the pattern in column 7
Answers
Iron occurs 8 valence electron and column 7 elements have 7 valence electrons that's why iron will not be kept in column 7.
What is column?
The periodic table groupings are seen as vertical columns with numbers ranging from 1 through 18.
What is valence electrons?The count of electrons occupy in outermost orbital of the particular atom, can be introduced as valence electrons.
Such kind of elements which posses 7 valence electrons , will be placed in column 7. Iron has 8 valence electron but column 7 elements have 8 valence electron that's why iron will not be kept in column 7.
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What is the formula for chlorine monoxide?
Answers
Final answer:
The formula for chlorine monoxide is Cl₂O, also known as dichlorine monoxide, which reacts with water to form hypochlorous acid.
Explanation:
The formula for chlorine monoxide is Cl₂O. This compound is also known as dichlorine monoxide. It is a yellowish-red gas and can be prepared through several reactions, including the reaction of chlorine gas with mercury oxide. Chlorine monoxide is notable for its role in the degradation of the ozone layer where, for example, it participates in the reaction cycle with ozone to form oxygen. In a reaction with water, it forms hypochlorous acid, illustrating its high water solubility and chemical reactivity.
Multiple Choice 1. The equation 2NO2↔N2O4 shows a system (1 point) in chemical equilibrium. in physical equilibrium. that does not reach equilibrium. that does not change. 2. If an endothermic reaction is in equilibrium, what will happen when you increase the temperature? (1 point) More reactants form. More products form. No change in the amounts of products or reactants occurs. The system does not reach equilibrium again. 3. One way to determine the degree of saturation of a solid-liquid solution is to drop a crystal of the solute into the solution. If the crystal sits at the bottom of the container, the solution is (1 point) saturated. unsaturated. supersaturated. concentrated. 4. To calculate the molarity of a solution, you need to know the moles of solute and the (1 point) volume of the solvent. volume of the solution. mass of the solution. volume of the solute. 5. Which of the following foods would NOT taste acidic? (1 point) lime tomato orange celery 6. A base is defined as a compound that produces (1 point) hydroxide ions in solution. hydrogen ions in solution. hydronium ions in solution. sodium ions in solution. 7. The salt that is formed during the reaction between potassium hydroxide and hydrochloric acid is (1 point) NaCl. H2O. KCl. K2Cl. 8. An acid can be defined as (1 point) a proton acceptor. a proton donor. neither a proton donor nor a proton acceptor. both a proton donor and a proton acceptor. Fill in the Blank 9. A substance dissolves in water by breaking up into smaller pieces. These pieces of the same substance spread throughout the water. This process is known as ____________________. (1 point) 10. Stirring increases the rate of solution of a solid in a liquid because solute particles in solution are moved _____________ the surface of the solid. (1 point)
Answers
in chemical equilibrium.
2. If an endothermic reaction is in equilibrium, what will happen when you increase the temperature? (1 point)
More products form.
3. One way to determine the degree of saturation of a solid-liquid solution is to drop a crystal of the solute into the solution. If the crystal sits at the bottom of the container, the solution is (1 point)
saturated
4. To calculate the molarity of a solution, you need to know the moles of solute and the (1 point)
volume of the solution
5. Which of the following foods would NOT taste acidic? (1 point)
celery
6. A base is defined as a compound that produces (1 point)
hydroxide ions in solution.
7. The salt that is formed during the reaction between potassium hydroxide and hydrochloric acid is (1 point)
KCl.
8. An acid can be defined as (1 point)
a proton donor.
9. A substance dissolves in water by breaking up into smaller pieces. These pieces of the same substance spread throughout the water. This process is known as ____________________. (1 point)
diffusion
10. Stirring increases the rate of solution of a solid in a liquid because solute particles in solution are moved _____________ the surface of the solid. (1 point)
away from
The questions cover various topics in chemistry including chemical equilibrium, reactions, acidity and basicity, solubility, and molarity. Among the key points are that the reaction 2NO2↔N2O4 forms a chemical equilibrium, an endothermic reaction in equilibrium produces more product when the temperature is increased, and a solution is saturated if a crystal of the solute sits at the bottom.
Explanation:1. The equation 2NO2↔N2O4 represents a chemical equilibrium.
2. If an endothermic reaction is in equilibrium, increasing the temperature will result in more products forming.
3. If a crystal of the solute sits at the bottom of the container, the solution is saturated.
4. To calculate the molarity of a solution, you need to know the moles of solute and the volume of the solution.
5. Out of the listed foods, celery would not taste acidic.
6. A base is defined as a compound that produces hydroxide ions in solution.
7. The salt formed during the reaction between potassium hydroxide and hydrochloric acid is KCl.
8. An acid can be defined as a proton donor.
9. A substance dissolves in water by breaking up into smaller pieces and spreading throughout the water. This process is known as solubility.
10. Stirring increases the rate of solution of a solid in a liquid because solute particles in solution are moved toward the surface of the solid.
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You are presented with a white solid and told that due to careless labeling it is not clear if the substance is silver fluoride, calcium fluoride, or potassium bromide. When you transfer the solid to a beaker and add water, the solid dissolves to give a clear solution. Next a Na2SO4(aq) solution is added and a white precipitate forms. What is the identity of the unknown white solid?
Answers
This leaves us with either silver fluoride or potassium bromide, as both are soluble in water.
Upon addition of sodium sulfate, a white precipitate forms, confirming that the substance was silver fluoride as the precipitate are of silver sulfate.
What is the missing part of the equation below?
²³⁸U₉₂→²³⁴Th₉₀ + ?
A. ⁴He₂
B. ⁴³⁸He₂
C. ⁴He₄
D. ²He₄
Answers
A. Missing part is ⁴He₂
You can also calculate it by adding/subtracting for atomic mass & atomic numbers
Hope this helps!
Answer:
A) ⁴He₂
Explanation:
²³⁸U₉₂ → ²³⁴Th₉₀ + A
To obtain the missing element (A), we have to first find it's atomic and mass numbers.
The mass number is the sum total of the protons and neutrons in an atom. It is usually equal to the superscript in an atom. for example in ²³⁸U₉₂ the mass number is 238.
The atomic number is the total of the protons in an atom. It is usually equal to the subscript in an atom. for example in ²³⁸U₉₂ the atomic number is 92.
In a chemical eqation, there's conservation of mass.
With this, mass number of products = mass number of reactants. same thing for the atomic number.
Mass number of Product = 238
Mass number of Reactant = 234 + x
238 = 234 + x
x = 238 - 234 = 4
Atomic number of product = 92
Atomic number of reactant = 90 + y
92 = 90 + y
y = 92 -90 = 2
So the atomic number of the missing element is 2 and its mass number is 4. ⁴A₂.
Among the elements, the only match is ⁴He₂. So the correct option is A
In chemistry class, you are given a density column with golden syrup, water, and oil. Your teacher gives you an unknown substance. The unknown substance is a solid, and it has been determined that the density of the unknown is 7.50 g/cm3. If this unknown solid was placed into the density tube, which of these best describe the outcome?
A) It would float on top of the oil.
B) It would sink directly to the bottom.
C) It would rest between the oil and the water.
D) It would float between the oil and the golden syrup.
Answers
Answer:
The correct answer is option B) It would sink directly to the bottom.
Explanation:
Hello!
Let's solve this!
Generally, solids have a higher density than liquids. In this case the densities are differentiated between the syrup, the oil and the water.
I think the solid would sink to the bottom.
After the explanation, we conclude that the correct answer is option B) It would sink directly to the bottom.
What is the element above the element in Group 3, Period 4?
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An ion is neutral and has no charge.
True
False
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Answer:false
Explanation:
In an atom of barium, how many electrons have l = 0 and ml = 1.
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Answer: 12 electrons
Explanation:
As the electrons move around the atom, they can move in any direction as long as they stay in their shell, and they are also constantly spinning. Shells or orbitals are specific distances from the nucleus and they are energy levels. Each of those shells has a name and there are a many ways that atomic shells are described.
First, the basic regions where electrons are found which is described using an "n" value, or the letters K, L, M, N, O, P, and Q. The "K" shell is the one closest to the nucleus, and "Q" is the farthest away. The second description looks at how electrons act inside of the shells, described with the "l" value which indicates in which suborbital an electron is found in (s, p, d, f, g, and h)
Quantum numbers are numbers associated with physical quantities conserved in certain quantum systems.
The main quantum number n This quantum number is related to both energy and the average distance between the nucleus and the electron. The values of this number, which corresponds to the number of the energy level, vary theoretically between 1 and infinity, but only atoms are known that have up to 8 energy levels in their fundamental state since the atomic number and the main quantum number are related by 2n2 = Z < 110.The secondary quantum number is L (l = 0,1,2,3,4,5,...,n-1), it indicates the shape of the orbitals and the sublevel of energy in which the electron is found. l = 0: Suborbit "s" (circular shape), it has a space for two electrons. l = 1: Suborbit "p" (flattened semicircular shape), it has three spaces for six electrons. l = 2: Sub-orbit "d" (lobular shape, with a nodal ring), it has five spaces for ten electrons. l = 3: Sub-orbit "f" (lobular with radial nodes), it has seven spaces for fourteen electrons. l = 4: Sub-orbit "g" (*), l = 5: Sub-orbit "h"The magnetic quantum number (m, ml), indicates the spatial orientation of the energy sublevel, "(m = -l,...,0,...,l)". For each value of l there are 2l+1 values of m.The spin quantum number (s, ms), Describes the intrinsic angular momentum of the electron. This angular momentum was originally interpreted in a classical way as the "self-rotation" of the electron on itself, and it was considered that given an axis the electron could do in two directions, opposite to each other. Therefore, the values that the spin quantum number can take are -1/2 and +1/2. In other words, each electron, in an orbit, spins on itself.So, L refers to the s subshell, so L=0 is related with the S-subshell. Ba is an atom found in the 6th shell, and it has the electronic configuration of [Xe]6s2 (1s2s2p3s3p4s3d4p5s4d5p6s), so there would be .12 electrons there because there are 6 s-orbitals with 2 electrons each. On the other hand, ml values rage from -L to L, and since the L value from this question is 0, there are no electrons that have both values of L=0 and ml=1. Since only one orbital of each type can have this magnetic quantum number and each orbital can host 2 electrons, we also have 12 electrons fitting this description.
Why must living things rely on thousands of catalysts for chemical reactions necessary for life?
Answers
Without catalysts, complex reactions like digestion would take too long and the organism could not extract energy from the nutrients it eats in a practical time frame.
In addition, speed is everything in the biological world.
Some reactions and their speed relative to other organisms reactions determines who survives and who doesn't, among other aspects of life.
If a plant is slow to photosynthesize and grow in a habitat high in competition for sunlight real estate, other autotrophs will surely take over.
Find the number of moles of water that can be formed if you have 150mol of hydrogen gas and 70mol of oxygen gas.
Answers
2H₂ + O₂ → 2H₂O
150 moles of Hydrogen requires 75 moles of Oxygen; however, 70 moles of Oxygen are present so Oxygen is the limiting reactant. We will calculate the amount of product using the amount of Oxygen.
Molar ratio of Oxygen : water:
1 : 2
Thus, moles of water = 2 x moles of oxygen
Moles of water = 2 x 70
Moles of water = 140
how much heat is released by 38 gram sample of water to freeze
Answers
When a 38 gram sample of water freezes it releases approximately 12.66 kJ of heat. This is because freezing is an exothermic process, meaning the substance releases energy in the form of heat.
Explanation:The process of freezing water is exothermic, meaning it releases heat. The amount of heat released when water freezes can be calculated using its enthalpy change upon freezing. For water, the enthalpy change upon freezing is approximately -6.0 kJ/mol. Here's how to calculate:
First, make sure that you have the appropriate conversion factors. Given that the molar mass of water is 18.015 g/mol, a 38 gram sample of water would be approximately 2.11 moles.Now use this information with the enthalpy change upon freezing (which is -6.0 kJ/mol) to calculate the amount of energy change (which will be measure in kJ). Multiply the number of moles by the enthalpy change: 2.11 moles * -6.0 kJ/mol = -12.66 kJ (negative because heat is being released). So, a 38 gram sample of water would release approximately 12.66 kJ of heat when it freezes.Learn more about Heat of freezing here:https://brainly.com/question/32765057
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When a 38 gram sample of water freezes it releases approximately 12.66 kJ of heat.
This is because freezing is an exothermic process, meaning the substance releases energy in the form of heat
To freeze a 38-gram sample of water, 12,692 joules of heat is released, calculated using the latent heat of fusion for water which is 334 J/g.To determine the amount of heat released when a 38-gram sample of water freezes, we must use the latent heat of fusion. The heat of fusion for water is 334 J/g. This value represents the amount of heat energy released or absorbed during the phase change of water from liquid to solid, and vice versa, without changing temperature.The formula to calculate the heat released is:
Heat released (Q) = mass (m) x heat of fusion (Lf)Given that: m = 38 grams and Lf = 334 J/g, we can plug in the values:
Q = 38 g x 334 J/g = 12,692 JTherefore, 12.66 kJ of heat is released when a 38-gram sample of water freezes.
Correct question is: How much heat is released by a 38-gram sample of water to freeze at its freezing point?
Do ionic or covalent substances tend to produce more ions in solution? ...?
Answers
the answer is A. ionic
Ionic compounds produce more ions in solution than covalent compounds, as they dissociate into their constituent ions, resulting in a greater number of dissolved particles compared to the individual molecules of covalent substances.
In solution, ionic compounds tend to produce more ions than covalent substances. When ionic compounds like sodium chloride (NaCl) dissolve in water, they separate into their constituent ions - for instance, NaCl yields one mole of Na+ ions and one mole of Cl⁻ ions, resulting in twice as many particles per mole as there were originally in the solid state.
On the other hand, covalent compounds typically dissolve in water as individual molecules without forming ions, such as glucose (C₆H₁₂O₆), which results in the same number of particles as moles dissolved.
For example, one mole of an ionic compound like NaCl will produce 2 moles of dissolved particles (ions), which is greater than the 1 mole of particles that results when one mole of a covalent compound, such as glucose, dissolves. This means that ionic substances affect the properties of solutions more significantly compared to an equivalent amount of dissolved covalent substances.
A 0.1 M solution enatiomerically pure chemical compound D has an observed rotation of 0.20 degrees in a 1 atm sample container. The Molecular mass of the compound is 150.
a. What is the specific rotation of D?(I already know this part )
b. What is the observed rotation if this solution is mixed with an equal volume of a solution that is 0.1 M in L, the enantiomer of D?
c What is the observed rotation if the solution of D is diluted with an equal volume of solvent?
d What is the specific rotation of D after the dilution described in c?
Answers
The mixing of enantiomers D and L yields a zero-degree observed rotation. Dilution of D with solvent maintains the same observed rotation, and also doesn't change the specific rotation.
Explanation:Enantiomeric compounds D and L are mirror images of each other, thus they will rotate plane-polarized light equally but in opposite directions. Therefore, when these are mixed in equal volumes, the rotation of one enantiomer will cancel out the rotation of the other, resulting in an observed rotation of 0 degrees.
The solution's concentration is being halved when the solution of D is diluted with an equal volume of solvent. But, because the observed rotation is directly proportional to the path length and inversely proportional to the concentration, the observed rotation will remain the same at 0.20 degrees, because you're essentially doubling the path length while halving the concentration.
The specific rotation will stay the same i.e 0.20 degrees after the dilution in question c), because it is an intrinsic property of the substance D and does not change with concentration or path-length.
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17. When does radioactive decay occur?
A. when an atom gains electrons
B. when neutrons accumulate in the nucleus
C. when the nucleus decays
D. when an atom loses electrons
18. Why does radioactive decay occur?
A. Nuclear forces disintegrate protons.
B. The electric force and nuclear forces are in opposition to each other.
C. The electric force causes electrons to be released.
Answers
The correct options are as follows:
17. C.
Radioactive decay refers to the process by which an unstable atomic nucleus loses energy by giving out radiations. The radiations emit can be in form of alpha or beta particles or gamma rays. Radioactive decay is a random process, that is, one can not predict when it would happen. Radioactive decay occurs when the nucleus of an atom decay and no longer have enough binding energy to hold the atomic sub particles together.
18. B.
Radioactive decay occurs when the nucleus no longer have enough energy to hold the sub particles in the nucleus together. This situation always occur when there are excess protons or neutrons in the nucleus of the atom. In the nucleus of an atom, two forces are usually at work, nuclear and electrostatic forces. While proton experience both of these forces, neutron only experience the nuclear force. These two forces that are in opposition bring about radioactive decay.
Radioactive decay occurs when the nucleus of an atom decays. The correct answer is
C: when the nucleus decays.Radioactive decay occurs due to the electric force and nuclear forces being in opposition to each other.
B: The electric force and nuclear forces are in opposition to each other. What is Radioactive decayRadioactive decay involves the spontaneous transformation of unstable atomic nuclei into more stable configurations, resulting in the emission of particles or electromagnetic radiation.
Reasons
In an atomic nucleus, protons are positively charged particles, and they experience repulsive electric forces due to their like charges. However, nuclear forces, specifically the strong nuclear force, help hold the protons and neutrons together in the nucleus. When the balance between these forces is disrupted, such as when the nucleus becomes unstable, radioactive decay can occur as the nucleus seeks a more stable configuration.
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For the following metal and non-metal combination reaction you have 3 moles of Na. How many moles of Cl2 would you need to add to have stoichiometrically equivalent amounts of NA and Cl2?
2Na(s) + Cl2(g) --> 2NaCl(s)
Answers
Moles of Na present = 3
2/1 = 3/x
x = 1.5
1.5 moles of Cl₂ needed to have stoichometrically equivalent amount
The moles of [tex]\rm Cl_2[/tex] needed to have stoichiometrically equivalent amounts of Na and [tex]\rm Cl_2[/tex] is 1.5 moles.
What is stoichiometrically equivalent?Stoichiometrically equivalent is defined as a definite quantity of one substances reacted with the definite quantity of other substances represented in the equation.
It can also be defined as the relationship between the quantities of reactant and product before, during and following equation.
The ratio of [tex]\rm NaCl_2[/tex] is 1:2 because in [tex]\rm NaCl_2[/tex] there is only one mole Na ion is present and 2 mole of Cl ion is present.
Thus moles of Na present = 3 moles
So, 2 / 1 = 3 / x
x = 3 / 2
x = 1.5 moles
Thus, the moles of [tex]\rm Cl_2[/tex]needed to have stoichiometrically equivalent amounts of Na and[tex]\rm Cl_2[/tex] is 1.5 moles.
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What name should be used for the ionic compound Pb(SO4)2
Answers
Is SiO2 Polar or Non-polar?
Answers
Silicon dioxide (SiO₂), also known as silica, is a non-polar molecule.
A non-polar molecule is a molecule that has an even distribution of electrical charge, meaning it does not have a positive or negative end.
The molecule's geometry and symmetry lead to its non-polar nature. SiO₂ consists of one silicon atom bonded to two oxygen atoms, forming a linear structure. The oxygen atoms are positioned on opposite sides of the silicon atom, resulting in a symmetric arrangement.
As a result, the bond dipoles cancel each other out, resulting in a non-polar molecule overall.
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how many grams of mercury are present in a barometer that holds 6.5mL of mercury? ...?
Answers
so grams of mercury present in a barometer that hold
per milliliter.
13.6*6.5 = 88.4
Answer: The mass of mercury will be 20.15 g.
Explanation:
Density is defined as the mass contained per unit volume.
[tex]Density=\frac{mass}{Volume}[/tex]
Given : Mass of bromine = ?
Density of bromine= [tex]3.1g/ml[/tex]
volume of bromine = 6.5 ml
Putting in the values we get:
[tex]3.1g/ml=\frac{mass}{6.5ml}[/tex]
[tex]mass=20.15g[/tex]
Thus the mass of bromine is 20.15 g.
how many grams of K2SO4 molar mass=174 g/mol would be needed to prepare 4.00 L of a 0.0510 M solution? ...?
Answers
0.051*4*174 = 35.496g
Which of the following ions would represent the ion of an element from group 2A
Answers
A car covers a distance of 112.6 km in 1.8 h. Calculate its speed in meters per second.
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1.8 h = 1.8 x 3600 s = 6480 s
112600 m / 6480 s
= 17 m/s
Answer: The speed of the car is 17.4 m/s
Explanation:
Speed is defined as the ratio of distance traveled to the time taken.
Mathematically,
[tex]\text{Speed}=\frac{\text{Distance traveled}}{\text{Time taken}}[/tex]
We are given:
Distance traveled = 112.6 km = 112600 m (Conversion used: 1 km = 1000 m)
Time taken = 1.8 hr = [tex]1.8\times 3600=6480s[/tex] (Conversion factor: 1 hr = 3600s)
Putting values in above equation, we get:
[tex]\text{Speed of car}=\frac{112600m}{6480s}=17.4m/s[/tex]
Hence, the speed of the car is 17.4 m/s
Given the reactant side of the total ionic equation for the neutralization reaction of sodium hydroxide (NaOH) with hydrochloric acid (HCl), write the total ionic equation (also known as the complete ionic equation) by entering both the reactant and the product species, separated by the reaction arrow. Na+(aq)+OH−(aq)+H+(aq)+Cl−(aq)→ ? Be sure to include the charges on the ionic species and the physical state of all the reactant and product species. Express your answer as a chemical equation.
Answers
Final answer:
The complete ionic equation for the neutralization of HCl by NaOH is Na+ + OH- + H+ + Cl- → H2O + Na+ + Cl-. The net ionic equation, omitting the spectator ions Na+ and Cl-, is H+ + OH- → H2O.
Explanation:
The total ionic equation for the neutralization reaction between sodium hydroxide (NaOH) and hydrochloric acid (HCl) is written as:
Na+ (aq) + OH− (aq) + H+ (aq) + Cl− (aq) → H₂O(l) + Na+ (aq) + Cl− (aq)
In this reaction, the Na+ and Cl− ions are spectator ions and do not participate in the actual neutralization. Thus, the net ionic equation, which shows the actual chemical change, is simply:
H+ (aq) + OH−(aq) → H₂O(l)
Here, the hydrogen ion (H+) from the acid reacts with the hydroxide ion (OH−) from the base to form water (H₂O), which is the only non-ionic product.
A common product of acid-base neutralization reaction is
Answers
Final answer:
A common product of acid-base neutralization reaction is water and a salt.
Explanation:
A common product of acid-base neutralization reaction is water and a salt. In this reaction, an acid and a base react to form a salt and water. For example, when hydrochloric acid (HCl) reacts with sodium hydroxide (NaOH), the products are sodium chloride (NaCl) and water (H2O).
You have two solutions of copper sulfate, one a deep blue and the other much paler. Is the first or second likely to be more concentrated? Is the first or
second likely to have higher absorbance
Answers
In a chemical reaction, water decomposes to form hydrogen and oxygen. What is the correct term for the water?
A.
an element
B.
an atom
C.
a product
D.
a reactant
Answers
________________________
Which of these equations is balanced?
a. h2o co ---> h2co3
b. 2nacl h2so4 ----> na2so4 2hcl
c. 2cao h2o ----> ca(oh)2
d. mn fe ----> mns fe?
Answers
Fe2O3 + 2Al -> Al2O3 + 2Fe
Calculate the mass of iron metal (in grams) that can be prepared from 150 grams of aluminum and 250 grams of iron(III) oxide.
Help please!
Answers
Mole ratio Fe2O3 : Al = 1:2
No. of moles of Fe2O3 = Mass/RMM = 250 / (55.8 * 2 + 16 * 3) = 1.56641604 moles
No. of moles of Al = 150/27 = 5.555555555 moles.
Mole ratio 1 : 2. 1.56641604 * 2 = 3.13283208 moles of Al, but you have 5.555555555 moles of Al. So Al is in excess. All of it won't react.
So take the Fe2O3 and Fe ratio to calculate the mass of iron metal that can be prepared.
RMM of Fe2O3 / Mass of Fe2O3 = RMM of 2Fe / Mass of Fe 159.6 / 250 = 111.6 / x x = 174.8 g of Fe
Answer : The mass of iron metal needed are, 87.4 grams
Solution : Given,
Mass of Al = 150 g
Mass of [tex]Fe_2O_3[/tex] = 250 g
Molar mass of Al = 27 g/mole
Molar mass of [tex]Fe_2O_3[/tex] = 160 g/mole
Molar mass of Fe = 56 g/mole
First we have to calculate the moles of Al and [tex]Fe_2O_3[/tex].
[tex]\text{ Moles of }Al=\frac{\text{ Mass of }Al}{\text{ Molar mass of }Al}=\frac{150g}{27g/mole}=5.55moles[/tex]
[tex]\text{ Moles of }Fe_2O_3=\frac{\text{ Mass of }Fe_2O_3}{\text{ Molar mass of }Fe_2O_3}=\frac{250g}{160g/mole}=1.56moles[/tex]
Now we have to calculate the limiting and excess reagent.
The balanced chemical reaction is,
[tex]Fe_2O_3+2Al\rightarrow Al_2O_3+2Fe[/tex]
From the balanced reaction we conclude that
As, 2 mole of [tex]Al[/tex] react with 1 mole of [tex]Fe_2O_3[/tex]
So, 1.56 moles of [tex]Al[/tex] react with [tex]\frac{1.56}{2}=0.78[/tex] moles of [tex]Fe_2O_3[/tex]
From this we conclude that, [tex]Fe_2O_3[/tex] is an excess reagent because the given moles are greater than the required moles and [tex]Al[/tex] is a limiting reagent and it limits the formation of product.
Now we have to calculate the moles of [tex]Fe[/tex]
From the reaction, we conclude that
As, 2 mole of [tex]Al[/tex] react to give 2 mole of [tex]Fe[/tex]
So, 1.56 mole of [tex]Al[/tex] react to give 1.56 mole of [tex]Fe[/tex]
Now we have to calculate the mass of [tex]Fe[/tex]
[tex]\text{ Mass of }Fe=\text{ Moles of }Fe\times \text{ Molar mass of }Fe[/tex]
[tex]\text{ Mass of }Fe=(1.56moles)\times (56g/mole)=87.4g[/tex]
Thus, the mass of iron metal needed are, 87.4 grams
As longitudional waves travel, particles in the medium are pushed together and then pulled apart.we call this
Answers
Measurements show that enthalpy of a mixture of gaseous reactants decreases by 228. kJ during a certain chemical reaction, which is carried out at a constant pressure. Furthermore, by carefully monitoring the volume change it is determined that -55kJ of work is done on the mixture during the reaction.
Calculate the change in energy of the gas mixture during the reaction.
Is the reaction exothermic or endothermic?
Answers
Answer:
-283 KJ, exothermic
Explanation:
We are given that
Enthalpy of a mixture of a gases reactants
Change in enthalpy=[tex]\Delat H[/tex]=-228 KJ
Where negative sign represents the enthalpy decreases.
Pressure=Constant.
Work don=w=-55 KJ
We have to calculate the change in energy of the gas mixture during the reaction.
At constant pressure, the change in enthalpy
[tex]\Delta H=\Delta U+P\Delta V[/tex]
Where w=[tex]-P\Delta V[/tex]
Where P=Constant
[tex]\Delta V=[/tex] Change in volume
[tex]\Delta U=[/tex] Change in energy
[tex]\Delta U=\Delta H-P\Delta V[/tex]
[tex]\Delta U=\Delta H+w[/tex]
Substitute the values then we get
[tex]\Delta U=-228-55=-283[/tex] KJ
Hence, the change in energy of the gas mixture during the reaction=-283 KJ
Change in enthalpy is negative it means the reaction is exothermic because the energy is evolved.
The reaction is exothermic, heat is evolved.
From the first law of thermodynamics we know that energy is neither created nor destroyed.
Therefore, the change in energy is obtained from the formula;
ΔU = ΔH + w
ΔU = change in energy
ΔH = Change in enthalpy (heat absorbed or evolved)
w = work done
ΔU = ?
w = -55kJ
ΔH = -228. kJ
ΔU= -228. kJ + ( -55kJ)
ΔU = -283 kJ
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