Answer:
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
cc
c
c
c
c
c
c
c
c
c
ccc
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
cc
c
c
c
AMOUNG US AND THE ANSWER IS C
Explanation:
Answer:
its c
Explanation:
Dissolution of KOH, ΔHsoln:
KOH(s) → KOH(aq) (10.1)
Neutralization of solid KOH, ΔHneut:
KOH(s) + HCl(aq) → H2O(l) + KCl(aq) (10.2)
1) Using Hess's law, show how to combine Reaction 10.1 and Reaction 10.2 to give
KOH(aq) + HCl(aq) → H2O(l) + KCl(aq) (10.3)
2)How should ΔHsoln and ΔHneut be combined (mathematically) to give the change in enthalpy for Reaction 10.3, ΔH?
Using Hess's law we found:
1) By adding reaction 10.2 with the reverse of reaction 10.1 we get reaction 10.3:
KOH(aq) + HCl(aq) → H₂O(l) + KCl(aq) ΔH (10.3)
2) The ΔHsoln must be subtracted from ΔHneut to get the total change in enthalpy (ΔH).
The reactions of dissolution (10.1) and neutralization (10.2) are:
KOH(s) → KOH(aq) ΔHsoln (10.1)
KOH(s) + HCl(aq) → H₂O(l) + KCl(aq) ΔHneut (10.2)
1) According to Hess's law, the total change in enthalpy of a reaction resulting from differents changes in various reactions can be calculated as the sum of all the enthalpies of all those reactions.
Hence, to get reaction 10.3:
KOH(aq) + HCl(aq) → H₂O(l) + KCl(aq) (10.3)
We need to add reaction 10.2 to the reverse of reaction 10.1
KOH(s) + HCl(aq) + KOH(aq) → H₂O(l) + KCl(aq) + KOH(s)
Canceling the KOH(s) from both sides, we get reaction 10.3:
KOH(aq) + HCl(aq) → H₂O(l) + KCl(aq) (10.3)
2) The change in enthalpy for reaction 10.3 can be calculated as the sum of the enthalpies ΔHsoln and ΔHneut:
[tex] \Delta H = \Delta H_{soln} + \Delta H_{neut} [/tex]
The enthalpy of reaction 10.1 (ΔHsoln) changed its sign when we reversed reaction 10.1, so:
[tex] \Delta H = \Delta H_{neut} - \Delta H_{soln} [/tex]
Therefore, the ΔHsoln must be subtracted from ΔHneut to get the total change in enthalpy ΔH.
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https://brainly.com/question/2082986?referrer=searchResultshttps://brainly.com/question/1657608?referrer=searchResultsI hope it helps you!
Doing Labs at home
I’m a junior and I’m staying home for this semester and I have to take chemistry and a lot of my work is Labs but I don’t know how to do them since I don’t have the materials at home to do the labs. Someone please help!!!
Answer:
go get the stuff.
Explanation:
For the reaction C + O2 = CO2, if 3 grams of carbon react with the oxygen, how many grams of carbon dioxide are produced?
In chemical reactions, _______ always involves the release of energy during the reaction process.
a) the breaking of bonds
b) the formation of bonds
c) the addition of a catalyst
d) overcoming activation energy
Answer:
a. the breaking of bonds
Answer:
B
Explanation:
Hey, I am almost positive that the answer to this question is B. The breaking of bonds uses the energy but when they are created it releases energy. I hope this helps, Have a good day!
If you have an aqueous solution that is 13.5 % Na3PO4 by mass, what is the molality of Na3PO4 in the solution?
Considering the definition of percentage by mass and molality, the molality of Na₃PO₄ in the solution is 0.948 [tex]\frac{moles}{kg}[/tex].
Percentage by mass
The percentage by mass expresses the concentration and indicates the amount of mass of solute present in 100 grams of solution.
In other words, the percentage by mass of a component of the solution is defined as the ratio of the mass of the solute to the mass of the solution, expressed as a percentage.
The percentage by mass is calculated as the mass of the solute divided by the mass of the solution, the result of which is multiplied by 100 to give a percentage. This is:
[tex]percentage by mass=\frac{mass of solute}{mass of solution}x100[/tex]
MolalityMolality is the ratio of the number of moles of any dissolved solute to kilograms of solvent.
The Molality of a solution is determined by the expression:
[tex]molality=\frac{number of moles of solute}{kilograms of solvent}[/tex]
This caseConsidering 100 grams as a sample of the solution, then the value of the percentage of concentration given indicates that 13.5 g correspond to Na₃PO₄.
Remember that percent concentration by mass is calculated using the mass of solute and the mass of the solution, which includes both the solute and the solvent. Then:
mass solution= mass solute + mass solvent
100 g= 13.5 g + mass solvent
100 g - 13.5 g= mass solvent
86.5 g= mass solvent
Then, you know:
number of moles of solvent= [tex]13.5 gramsx\frac{1 mole}{163.94 grams} =0.082 moles[/tex] being 163.94 [tex]\frac{grams}{mole}[/tex]the molar mass of Na₃PO₄, this is the amount of mass a substance contains in one mole.mass of solvent= 86.5 grams= 0.0865 kg (being 1000 g= 1 kg)Then, replacing in the definition of molality:
[tex]molality=\frac{0.082 moles}{0.0865 kg}[/tex]
Solving:
molality= 0.948 [tex]\frac{moles}{kg}[/tex]
Finally, the molality of Na₃PO₄ in the solution is 0.948 [tex]\frac{moles}{kg}[/tex].
Learn more about:
mass percentage:brainly.com/question/19168984?referrer=searchResultsbrainly.com/question/18646836?referrer=searchResultshttps://brainly.com/question/20037730?referrer=searchResultshttps://brainly.com/question/25148948molalitybrainly.com/question/20366625?referrer=searchResultsbrainly.com/question/4580605?referrer=searchResultsTRUE or FALSE 1. Badminton began in India as a game called poona. 2. The shuttle was then called a bird because it was made from goose feather. 3. Ti jian zi played by throwing up in the air. 4. Racket is made of either metal or synthetic materials. 5. Head, throat, shaft, and handle are the parts of the rackets. 6. Shuttlecock is made up of 16 goose feathers. 7. Forehand, Backhand, and Sidestroke are the three basic skills of Badminton. 8. Backhand is use to depends on the type of shot to be executed. 9. Stroke means to propel with a controlled swinging blow. 10. The whole size of the badminton court has 39 meters.
Answer:
1.false
2.true
3.true
4.true
5.false
6.false
7.false
8.true
9.false
10.true
Explanation:
I took the test
If 25 g of Al was added to 90 g of HCl, what mass of H2 will be produced?
Answer:
im pretty sure its 2.7 gms
Explanation:
im not for sure tho
a 13.5 g sample of zinc(zn) heated from 24.2 degrees celsius to 83.6 degrees celsius that absorbs 312j of heat? use specific heat
Explanation:
83.6-24.2= 59.4 which is the change in heat
A radioactive sample has a half life of 1 hour. If you start with 1.000 gram of it at noon, how much of it remains at 4pm
The amount of the sample remaining at 4pm is 0.0625 g
We'll begin by calculating the number of half-lives that has elapsed
Half-life (t½) = 1 hour
Time (t) = 4 hour
Number of half-lives (n) =?n = t / t½
n = 4 / 1
n = 4Finally, we shall determine the amount the sample remaining at 4pmNumber of half-lives (n) = 4
Initial amount (N₀) = 1 g
Amount remaining (N) =?[tex]N = \frac{N_0}{ {2}^{n}} \\ \\ N = \frac{1}{ {2}^{4}} \\ \\ N = \frac{1}{16} \\ \\ N = 0.0625 \: g[/tex]
Thus, the amount remaining at 4pm is 0.0625 g
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Is there more than one possible model that could be inferred from Rutherford’s data?
Rutherford proposed the nuclear model of atom. The only one model which can be inferred from this model is nucleus with protons and revolving electrons around.
What is Rutherford model?Rutherford proposed some aspects of atomic structure based on his gold foil experiment. He discovered that the alpha ray is scattering from foil by the repulsion it experienced from the metal.
This results lead to the discovery of positively charged particles in atom latter called as protons. Rutherford proposed that theses protons are located inside the nucleus and the electrons are revolving around the nucleus.
Latter Niels Bohr his student interpreted the nuclear model of Rutherford with quantum mechanics and theory of max planck and he proposed the equations for the determination of energy and momentum of electrons and the radius of atom.
Therefore, no other inferences except the presence of protons and revolving electrons can be obtained from Rutherford's model of atom.
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describe radioisotope
Answer:
It is an unstable form of a chemical element that releases radiation as it breaks down and becomes more stable.
When magnesium chloride is formed what question will the student need to ask prior to writing the formula?
A.
What are the oxidation numbers of each atom?
B.
What is the total number of electrons for each atom?
C.
What is the state of matter of each element in the formula?
D.
What period does magnesium belong to?
Prior to writing the chemical formula of magnesium chloride, a question which any student will need to ask is: A. What are the oxidation numbers of each atom?
A chemical formula can be defined as a scientific notation that is used to show (represent) the type and total number of atoms that constitute a particular chemical molecule or compound, by using the oxidation number, chemical symbols and subscripts.
Hence, a student would need to know the oxidation numbers of each atom when magnesium chloride is formed after a chemical reaction.
In Chemistry, an oxidation number represents the number of electrons gained or lost by an atom of a chemical element during a chemical reaction.
In conclusion, when magnesium chloride is formed, a question which the student will need to ask prior to writing the chemical formula is "what are the oxidation numbers of each atom?"
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Which of the following is a way to increase pressure on a gas?
Answer:
increase the number of gas particles
Explanation:
The process of returning mines to their original state is called ________________________.
Answer:
Mine Reclamation.Explanation:
The process of returning mines to their original state is called Mine Reclamation. HOPE THIS HELPS :)Which sentence best describes what happens during a change of state from
a solid to a liquid?
A. The temperature stays the same and the particle speed increases.
B. The temperature stays the same and the particle speed stays
constant
C. The temperature increases and the particle speed stays constant.
D. The temperature decreases and the particle speed decreases.
SUBMIT
Answer:
B
Explanation:
as temperature rises, the particles gain kinetic energy (they will move faster) so if temperatures stays constant, so will the movement or vibration of the particles
A metal (FW 341.1 g/mol) crystallizes into a body-centered cubic unit cell and has a radius of 1.74 Angstrom. What is the density of this metal in g/cm3
This problem provides the molar mass and radius of a metal that has an BCC unit cell and the density is required.
Firstly, we consider the formula that relates molar mass and also includes the Avogadro's number and the volume of the unit cell:
[tex]\rho =\frac{Z*M}{V*N_A}[/tex]
Whereas Z stands for the number of atoms in the unit cell, M the molar mass, V the volume and NA the Avogadro's number. Next, since BCC is able to hold 2 atoms and M and NA are given, we calculate the volume of the atom in the unit cell given the radius in meters:
[tex]V=a^3=(\frac{4R}{\sqrt{3} } )^3=(\frac{4*1.74x10^{-10}m}{\sqrt{3} } )^3=6.49x10^{-29}m^3[/tex]
And finally the required density in g/cm³:
[tex]\rho =\frac{2*341.1g/mol}{6.49x10^{-29}m^3\frac{m^3}{atom} *6.022x10^{23}\frac{atom}{mol} } =17455257.8g/m^3\\\\\rho=17.5g/cm^3[/tex]
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how is atom and molecules related to our sense of smell?
Answer:
Atoms themselves do not have a smell. Molecules do.
Explanation:
What happens is that particular molecules bind to receptors in our nose, activating nerves, that then send signals to our brain, which we then interpret and perceive as “smells”. Different molecules bind to different receptors, which is why we can perceive a number of different smells
Calculate the second ionization energy of the metal M (?Hion2� in kJ/mol) using the following data:
Lattice enthalpy of MO(s), ?Hl� = -2383 kJ/mol
Bond dissociation enthalpy of O2(g) = +498 kJ/mol
First electron affinity of O = -141 kJ/mol
Second electron affinity of O = +744 kJ/mol
Enthalpy of sublimation of M = + 130 kJ/mol
First ionization energy of M = + 267 kJ/mol
Standard enthalpy of formation of MO(s), ?Hf� = -307 kJ/mol
From the information provided in the question, the second ionization energy of the metal is 578 kJ/mol.
From the question, we have the following information;
Lattice enthalpy of MO(s) = -2383 kJ/mol
Bond dissociation enthalpy of O2(g) = +498 kJ/mol
First electron affinity of O = -141 kJ/mol
Second electron affinity of O = +744 kJ/mol
First ionization energy of M = + 267 kJ/mol
Heat of sublimation of M = + 130 kJ/mol
Standard enthalpy of formation of MO(s) = -307 kJ/mol
Using Hess law of constant heat summation;
ΔHf = ΔHs + BE + ∑IE + ∑EA + U
ΔHs = Heat of sublimation of metal
ΔHf = Heat of formation MO
BE = Bond energy of O2
∑EA = sum of electron affinities of Oxygen
∑IE = Sum of the ionization energies of M
U = Lattice energy of MO
Let the second ionization energy be x
Substituting values;
(-307) = 130 + 498 + (267 + x) + 603 + (-2383)
(-307) = -885 + x
-x = -885 + 307
-x = -578
x = 578 kJ/mol
The second ionization energy of the metal is 578 kJ/mol.
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Which two substances are reactants in the chemical reactions of cellular respiration?
Answer:
The answer is A and C.
Explanation:
The reactants in the process of cellular respiration are oxygen and glucose, respectively. It is ATP that serves as the primary product of cellular respiration, with carbon dioxide and water serving as waste products.
Sugar is a glucose.
Oxygen and glucose are the two substances that are reactants in the chemical reactions of cellular respiration. Therefore, the correct options are options A, C.
What is cellular respiration?Through the process of cellular respiration, organisms mix oxygen with food molecules, directing the chemical energy contained in these substances towards life-sustaining processes while excreting carbon dioxide and water as waste. Foods are broken down by microorganisms that do not require oxygen in a process known as fermentation.
Adenosine triphosphate (ATP), an energy-rich compound that absorbs the chemical energy generated by the decomposition of food molecules then releases it to power other cellular functions, is one goal of the breakdown of foodstuffs. ATP is created when the energy found inside chemical bonds is converted from one form to another. Oxygen and glucose are the two substances that are reactants in the chemical reactions of cellular respiration.
Therefore, the correct options are options A, C.
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Name the following Type 1 compounds:
1. Naci
2. KI
3. Cas
4. CsBr
5. Mgo
6. CSF
7. AICI:
8. Mg2
9. Rb20
10.Sr12
11.KAS
Answer:
44
Explanation:
6) 0.5 moles of gas is kept at 2.0 L of volume and 0.75 atm of pressure. What is the temperature of the gas in K?
Answer:
310K
Explanation:
Rearrange PV=nRT to get T=PV/nR
T=(2.0L)(0.75atm)/(0.5mol)(0.08206)
=36.5 or 37
add 273 for K to get
310
Oxidation unit test
Please help ASAP!!!
Which statement correctly describes the oxidation number of the manganese atom (Mn) in Mnl2 and MnO2?
O Manganese has an oxidation number of +4 in Mnl2 and +2 in MnO2.
o Manganese has an oxidation number of +2 in Mnl2 and +4 in MnO2.
o Manganese has an oxidation number of +4 in both Mnl2 and MnO2.
Manganese has an oxidation number of +2 in both Mnl2 and MnO2.
In this case, according to the given information about the oxidation numbers and the compounds given, it turns out possible to figure out the oxidation number of manganese in both MnI2, manganese (II) iodide and MnO2, manganese (IV) oxide, by using the concept of charge balance.
Thus, we can define the oxidation state of iodine and oxygen as -1 and -2, respectively, since the former needs one electron to complete the octet and the latter, two of them.
Next, we can write the following [tex]x[/tex], since manganese has five oxidation states, and it is necessary to calculate the appropriate ones:
[tex]Mn^xI_2^-\\\\Mn ^xO_2^{-2}[/tex]
Next, we multiply each anion's oxidation number by the subscript, to obtain the following:
[tex]Mn^xI_2^-\rightarrow x-2=0;x=+2\\\\Mn ^xO_2^{-2}\rightarrow x-4=0;x=+4[/tex]
Thus, the correct choice is Manganese has an oxidation number of +2 in Mnl2 and +4 in MnO2.
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In the reaction N2 + 3H2 → 2NH3 how many moles of ammonia will be produced from 1.30 mol
of hydrogen and excess nitrogen?
According to the equation given, we have N2 + 3H2 → 2NH3.
Therefore, to determine the moles of NH3 we have to do the following-
1.3 mol H2 × 2 mol NH3 / 3 mol H2 = 0.87 mol
Answer: .87 moles of NH3 are produced from 1.3 moles of H2.
I hope this helps!
Thin-layer chromatography explain ?????
Answer:
Explanation:
Thin-layer chromatography (TLC) is a chromatography technique used to separate non-volatile mixtures. ... After the sample has been applied on the plate, a solvent or solvent mixture (known as the mobile phase) is drawn up the plate via capillary action.
Explain why there might be a change in the density of a forged product as compared to that of the cast blank.
Answer:
Forged parts are often tougher than cast parts. This can be determined by performing tensile tests on various areas on the parts. Additionally, the microstructures of forged and cast parts can be used to determine if a part was forged or cast. The microstructure of a cast part will have a more uniform grain structure.
Explanation:
A 14.0 L container at 323 K holds a mixture of two gases with a total pressure of 8.00 atm. If there are 1.50 mol of Gas A in the mixture, how many moles of Gas B are present
The number of moles of gas B present in the gas mixture is 2.72 moles.
The given parameters;
Volume of the gases, V = 14 LTemperature of the gases, T = 323 KTotal pressure of the gases, P = 8 atmNumber of moles of gas A = 1.5 molesThe total number of moles of the gases is calculated by applying ideal gas law;
PV = nRT
where;
R is ideal gas constant = 0.0821 L.atm./mol.K
n is the total mole of the gases
[tex]n =\frac{PV}{RT} \\\\n = \frac{8 \times 14}{0.0821 \times 323} \\\\n = 4.22 \ moles[/tex]
The number of moles of gas B is calculated as follows;
[tex]n_B = 4.22 - n_A\\\\n_B = 4.22 - 1.5\\\\n_B = 2.72 \ moles[/tex]
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what is the mass number of an atom with 3 protons,4 nuetrons, and 3 electrons
Answer:
Neon 10, mass: 20.18
Explanation:
. Nhiệt độ ban đầu của 344 g một mẫu sắt là 18,2oC. Nếu mẫu sắt này hấp thụ 2,25 kJ nhiệt lượng thì nhiệt độ cuối của mẫu sắt này là bao nhiêu? (CFe = 0,449 J/g.K).
Answer:
i can't understand the question
how is waste removed from the body
Waste is removed from the body in various ways. Kidneys filter out metabolic waste, excess fluid and eliminate it in the form of urine. Lungs exhale CO2 from the deoxygenated blood. The undigested solid waste is egested out from the large intestine. Excretion is the process of removing wastes and excess water from the body. It is one of the major ways the body maintains homeostasis. Organs of excretion make up the excretory system. They include the kidneys, large intestine, liver, skin, and lungs.
solvent extraction explain ???
Answer:
this the partial removal of a substance from a solution or mixture by dissolving it in another immiscible solvent in which it is more soluble.