Final temperature of the two pieces of metal is 32.25°C
Temprature is the degree of hotness or coldness of the object
Here given data is
Mass of iron = 150 g
Mass of copper = 275 g
Specific heat of iron = 25.09 J/mol°C
Specific heat of copper = 25.46J/mol°C
Temprature in iron = 47°C = initial temprature = T₁
Temprature in copper = 20°C = initial temprature = T₁'
So here we have to find final temprature of two pieces of metal =?
So, the formula is Q =mcΔT
Q = (150 g - 275 g) × (25.09 J/mol°C - 25.46J/mol°C) × ( 47°C-20°C )
Q = 125×0.37×27
Q = 243 J
243 J/125×0.37 = 5.25°C = change in temprature
Initial temprature = 27°C
Final temprature = ?
ΔT = T₂ - T₁
27°C = T₂ - 5.25°C
T₂ = 27°C + 5.25°C
T₂ = 32.25°C
Final temperature of the two pieces of metal is 32.25°C
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stomach acid has a pH of 1 and tomatoes have a pH of 4. How many times stronger than tomatoes is stomach acid?
We must take into account the definition of pH, and this represents the concentration of H+ ions([H+]). It can be defined with the following equation:
[tex]pH=-\log \lbrack H^+\rbrack[/tex]To determine how many times the acid is stronger than the tomato, we must calculate the concentration of H+ ions for each pH value, to do so we clear [H+] from the previous equation:
[tex]\lbrack H^+\rbrack=10^{-pH}[/tex]Now we substitute each pH value into the equation:
[tex]\begin{gathered} \lbrack H^+\rbrack_{StomachAcid}=10^{-1} \\ \lbrack H^+\rbrack_{\text{Tomatoes}}=10^{-4} \end{gathered}[/tex]Therefore we will have to:
[tex]\frac{\lbrack H^+\rbrack_{StomachAcid}}{\lbrack H^+\rbrack_{\text{Tomatoes}}}=\frac{10^{-1}}{10^{-4}}=\frac{1}{10^{-3}}=10^3=1000[/tex]Therefore, stomach acid will be 1000 times stronger than the tomatoes.
How many grams of carbon monoxide gas would be contained in 710 mL at 119 kPa and 37 C
Answer
0.9166 g CO
Procedure
Considering the conditions and parameters given ideal gas law will be assumed.
[tex]PV=nRT[/tex]The gas constant is 8.3144 L⋅kPa⋅ K⁻¹⋅mol⁻¹
Converting the current data to the required units
710 mL = 0.710 L
37 °C = 310.15 °K
Solving for moles and substituting the variables with the available data
[tex]n=\frac{PV}{RT}=\frac{119\text{ }kPa(0.710)L}{8.3144\text{ L. kPa\cdot}\degree\text{K^^^^207b^^b9\cdot mol^^^^207b^^b9 \lparen310.15\rparen }\degree K}=0.0327\text{ }moles\text{ CO}[/tex]Transforming from moles to grams using the molecular weight
[tex]0.0327\text{ }moles\text{ }CO\frac{28.01\text{ }g}{1\text{ }mole}=0.9166\text{ }g\text{ }CO[/tex]In one demonstration of this reaction, 39.00 mL of H2 are collected over water at 25°C. Atmospheric pressure is 749.0 mmHg. How many grams of H2 are collected?
Taking into account the ideal gas law, a mass of 0.00314 grams of H₂ is collected.
Definition of ideal gas lawAn ideal gas is a theoretical gas that is considered to be composed of randomly moving point particles that do not interact with each other. Gases in general are ideal when they are at high temperatures and low pressures.
The pressure, P, the temperature, T, and the volume, V, of an ideal gas, are related by a simple formula called the ideal gas law:
P×V = n×R×T
where:
P is the gas pressure.V is the volume that the gas occupies.T is its temperature.R is the ideal gas constant. The universal constant of ideal gases R has the same value for all gaseous substances. The numerical value of R will depend on the units in which the other properties are worked.n is the number of moles of the gas. Mass of H₂In this case, you know:
P= 749 mmHg= 0.985526 atm (being 760 mmHg= 1 atm)V= 39 mL= 0.039 L (being 1000 mL= 1 L)n= ?R= 0.082 (atm×L)÷(mol×K)T= 25 C= 298 K (being 0 C= 273 K)Replacing in the ideal gas law:
0.985526 atm× 0.039 L = n× 0.082 (atm×L)÷(mol×K)× 298 K
Solving:
[0.985526 atm× 0.039 L]÷ [0.082 (atm×L)÷(mol×K)× 298 K]= n
0.00157 moles= n
Considering that the molar mass of H₂ is 2 g/mole, the mass can be calculated as:
mass= number of moles× molar mass
mass= 0.00157 moles× 2 g/mole
mass= 0.00314 grams
Finally, you collected a mass of 0.00314 grams.
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A balloon has a volume of 1785 mL at 25°C, if the volume of balloon changes to 1.25 L, what is the new temperature in degree Celcius atconstant pressure and amount?
We work here with Charles' Law. The equation used here is:
V1/T1 = V2/T2 (1)
(pressure and amount constant)
V is for volume and T for temperature
V1 = 1785 mL
1 L = 1000 mL ==> V1 = 1.785 L
T1 = 25 °C = 25 °C + 273 = 298 K
V2 = 1.25 L
T2 = unknown
From (1) we clear T2:
T2 = V2 x T1/V1 = 1.25 L x 298 K/1.785 L = 209 K approx.
T2 = 209 K - 273 = -64 °C
Answer: T2 = -64 °C
Assuming that each double-displacement reaction occurs, predict the products and write each balanced chemical equation.
a.
Sn(OH)2 + FeBry -*?
b. CsNO3 + KCI -* ?
The products of the double displacement reactions are given in the equations of the reaction below:
a. 3 Sn(OH)₂ (aq) + 2 FeBr₃ (aq) ---> 3 SnBr₂ (aq) + 2 Fe(OH)₃ (s)
Iron (iii) hydroxide is obtained as a precipitate
b. CsNO₃ (aq) + KCI (aq) ---> CsCl (aq) + KNO₃ (aq)
No double displacement reaction occurs as both products are soluble.
What are double displacement reactions?Double displacement reactions are reactions in which there is an exchange of radicals by two compounds when solutions of the compounds are added together.
In a double displacement reaction, an insoluble precipitate is obtained since one of the products of the double displacement reaction is insoluble in aqueous solutions.
The products of the double displacement reactions are given in the equations of the reaction below:
a. Reaction between Sn(OH)₂ and FeBr₃
3 Sn(OH)₂ (aq) + 2 FeBr₃ (aq) ---> 3 SnBr₂ (aq) + 2 Fe(OH)₃ (s)
Iron (iii) hydroxide is obtained as a precipitate
b. Reaction between CsNO₃ and KCI
CsNO₃ (aq) + KCI (aq) ---> CsCl (aq) + KNO₃ (aq)
No double displacement reaction occurs as both products are soluble.
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Using the balanced equation:3 Ag2S + 2 Al -> Al2S3 + 6 Ag0.88 moles of Ag2S = ? grams Ag
Answer: 189.5g of Ag would be produced from 0.88 moles of Ag2S
Explanation:
The question requires us the amount of Ag, in grams, that would be produced from 0.88 moles of Ag2S, according to the following equation:
[tex]3Ag_2S+2Al\rightarrow Al_2S_3+6Ag[/tex]To solve this problem, which is a mol to mass stoichiometry problem, we'll need to follow the steps:
moles of Ag2S → moles of Ag → mass of Ag
To do that, we'll need to use the molar mass of Ag (107.87 g/mol) and the mole ratio between Ag2S and Ag, as given by the balanced chemical equation (6 moles of Ag are produced from 3 moles of Ag2S).
We can calculate the number of moles of Ag that would be produced from 0.88 moles of Ag2S as:
3 mol Ag2S -------------------------- 6 mol Ag
0.88 mol Ag2S --------------------- x
Solving for x, we'll have:
[tex]x=0.88mol\text{ Ag}_2S\times\frac{6mol\text{ Ag}}{3mol\text{ Ag}_2S}=1.76mol\text{ Ag}[/tex]Therefore, 1.76 moles of Ag would be produced from 0.88 moles of Ag2S.
Next, we need to convert the number of moles of Ag calculated to its correspondent mass. Knowing that the molar mass of Ag is 107.87 g/mol, we can calculate:
[tex]\begin{gathered} number\text{ of moles = }\frac{mass\text{ \lparen g\rparen}}{molar\text{ mass \lparen g/mol\rparen}}\rightarrow mass\text{ = number of moles}\times molar\text{ mass} \\ \\ mass\text{ = 1.76mol}\times107.87g/mol=189.8g \end{gathered}[/tex]Therefore, 189.5g of Ag would be produced from 0.88 moles of Ag2S.
The soft drinks sold at county fairs are often dispensed from large pressurized containers that contain carbon dioxide gas above the liquid at a partial pressure of about 4 atm, compared to carbon dioxide’s normal partial pressure of 0.00035 atm in the air at sea level. a. Describe the reversible change that takes place inside one of these soft drink containers when the pressure of CO2 above the liquid is first brought from 0.00035 atm to 4 atm. Explain why this system comes to a dynamic equilibrium in which there is no net change in the amount of gas above the liquid or the amount of gas dissolved in the liquid.
CO2 particles move faster through the solution. Gas solubility increases as liquid CO2 partial pressure rises.
Dynamic equilibrium occurs when the solution rate matches the escape rate, and neither the gas above the liquid nor the gas dissolved in it changes.
This is further explained below.
What is dynamic equilibrium?Generally, The idea of partial pressure is connected to the changes that occur in soft drink containers. Since there are no gas particles in the liquid when we add CO2 at a typical partial pressure of 0.00035, the CO2 gas begins to move into the solution at a faster pace than it can leave.
But when the concentration of CO2 gas rises, it begins to diffuse into the liquid, and eventually, a dynamic equilibrium is attained when the rate of the solution equals the rate of escape.
However, as we continue to add CO2 to this dynamic equilibrium, its partial pressure will rise until it reaches 4 atm, and this rise in partial pressure accelerates the rate of solution. Thus, raising the partial pressure of CO2 causes this reversible transformation to occur.
When the rate of the solution equals the rate of escape, this is known as dynamic equilibrium, and neither the quantity of gas above the liquid nor the amount of gas dissolved in it changes in any significant way.
Now here comes what role is played by partial pressure. When the rate of solution and the rate of escape reach a dynamic equilibrium and we begin to introduce additional CO2 gas to this dynamic equilibrium stage.
The CO2 gas particle's partial pressure and concentration both rise. Because of the increased rate of collision between the surface of CO2 gas and the surface of the liquid particles due to the increasing concentration, the rate of solution also rises. The pace of solution has now surpassed the rate of escape.
As a result, the rate at which CO2 gas particles travel through the solution increases. This is how a rise in CO2 partial pressure over liquid causes a rise in gas solubility.
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What is the relationship between n, ℓ, and the total number of nodes?
The number of planar nodes = ℓ.
The number of spherical nodes = n - ℓ - 1.
The relationship between n, ℓ, and the total number of nodes is given by the expression; Number of spherical nodes = n - ℓ - 1.
What is the number of nodes?The number of nodes has to do with the points on the orbital where there is a zero electron density. It is the points along the orbital where there re no electrons. Recall that the orbitals are the regions in space where there is a high probability of finding an electron.
There are various orbitals and the number of nodes of each of the orbitals does vary. The s orbital has no nodes while the p orbital is known to have one node.
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What type of blood vessels can you find in most mammals?
A) tendons, ligaments, and capillaries
B) nerves and veins
C) aorta and ventricle
D) arteries, capillaries, veins
Answer:
Explanation:
the answer is D
Answer:
D
Explanation:
capillaries veins and arteries
30.Vegetable soup is classified as which of the following?Select one:a. An atom.b. A compound.c. An element.d. A mixture.
A mixture in Chemistry is defined as a material made up of two or more different chemical substances, and it will not present a homogeneous solution, but instead a heterogeneous appearance, just like a vegetable soup, which is a mixture of many substances, answer letter D
How many kilojoules are required to melt 15g of ice at 0 degrees celsius and raise the temperature of the liquid that forms to 85 degrees celsius.
The amount of heat, in kilojoules, that is required to melt 15 g of ice at 0 degrees Celsius and raise the temperature of the liquid to 85 degrees Celsius is 10.3178 kJ.
Heat changeThe process involves melting of ice at 0 degrees Celsius and then heating the resulting water to a temperature of 85 degrees Celsius.
Solid water is first converted to liquid water without a change in temperature.Liquid water is heated without a change of state to 85 degrees Celsius.Now, let's calculate the heat change of the process:
Heat change (ΔH) = n x heat of fusion) + mcΔt
Where n = number of moles
m = mass = 15 g
c = specific heat capacity of water = 4.81 J/g[tex]^oC[/tex]
heat of fusion = 6010 J/mole
In this case, n = mass/molar mass
= 15/18
= 0.83 moles
ΔH = (0.83 x 6010) + 15 x 4.81 x (85 - 0)
= 10317.8 Joules
But 1000 Joules = 1 kilojoules
Thus, 10317.8 joules = 10.3178 kJ
The kilojoule of heat required to melt the ice and raise the temperature of the resulting water to 85 degrees Celsius is 10.3178 kJ.
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Consider the following reaction in the forward direction. Identify the base:
CH₃O⁻ + H₂O ⇌ CH₃OH + OH⁻
If we consider the reaction CH₃O⁻ + H₂O ⇌ CH₃OH + OH⁻ in the forward direction, the base in the reaction is CH₃O⁻
A compound can be acidic, basic or neutral in nature. Basicity of the compound is determined when it either releases hydroxide ions, donates electrons or else accepts the protons from a compound.
In the reaction CH₃O⁻ + H₂O ⇌ CH₃OH + OH⁻:
CH₃O⁻ accepts proton or [H+] ion to become CH₃OH. Thus, CH₃O⁻ is the base in the reaction
H₂O donate [H+] ion or proton, therefore H2O change into OH-. Thus, H₂O is an acid in the reaction.
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8.In the equation 2 NH3 + H2O + CO2 ---> (NH4)2CO3, which of the following is a product?Select one:a. CO2 b. H2O c. NH3 d. (NH4)2CO3
According to the explanation given in a previous session, the compounds that comes after the arrow are classified as product, and the compounds that comes before are classified as reactant, therefore in this reaction, (NH4)2CO3 is the product of the reaction, letter D
What is the name of the product formed by the reaction of propylide ion and 2-chloropropane?
A 4.50 L sample of neon at 11.08 atm is added to a 12.0 L cylinder that contains argon. If the pressure in the cylinder is 7.15 atm after the neon is added, what was the original pressure (in atm) of argon in the cylinder?
The original pressure of argon in the cylinder is 5.68 atm.
What is the original pressure of the argon?
The original pressure of argon in the cylinder is calculated as follows.
Apply the concept of molar ratio or molar proportion to determine the original pressure of argon in the cylinder.
Pr = [(Pn x Vn) + (Pa x Va) ] / (Vn + Va)
where;
Pr is the resultant pressure of the mixture of gases = 7.15 atmPn is the original pressure of neon = 11.08 atmPa is the original pressure of argonVn is the volume of neon = 4.5 LVa is the volume of argon = 12 L7.15 = [(11.08 x 4.5) + (12 x Pa)] / (4.5 + 12)
7.15(4.5 + 12) = 49.86 + 12Pa
117.98 = 49.86 + 12Pa
68.12 = 12Pa
Pa = 68.12/12
Pa = 5.68 atm
Thus, the original pressure of argon in the cylinder is determined by applying concept of molar ratio.
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In the reaction of 2Mg + O2 →2MgO
How many moles of O2 are required to react with 14 moles of Mg?
Answer:
Explanation:The given reaction is
It is an example of an oxidation reaction because in the above reaction, is getting oxidized to form .
Also, it is a type of combination reaction because magnesium reacts with oxygen to form a single product i.e. Magnesium oxide.
What is the mass in grams of aluminum metal (26.98 g/mol) that reacts to form 2.80 g of iron (55.85 g/mol)?
3 FeO (l) + 2 Al (l) → 3 Fe (l) + 1 Al2O3
Starting with 0.450 g of potassium chlorate (molar mass 122.55 g/mol), a student determined that the reaction released 0.156 g of oxygen gas. Calculate the percent yield for O2.
2 KCIO3 (s) → 2KCl (s) + 3 O2
The mass of aluminum metal that reacts to form 2.80 g of iron according to the reaction would be 0.9017 g.
The percent yield of the reaction if 0.450 g of potassium chlorate reacts according to the equation would be 87.05%.
Yield of reactionsConsider the first reaction:
[tex]3 FeO (l) + 2 Al (l) -- > 3 Fe (l) + 1 Al_2O_3[/tex]
The mole ratio of Al and Fe is 2:3.
2.80 g of Fe = 2.8/55.85
= 0.0501 moles
Equivalent mole of Al = 2/3 x 0.0501
= 0.0334 moles
Mass of 0.0334 moles Al = 0.0334 x 26.98
= 0.9017 g
Consider the second reaction:
[tex]2 KCIO_3 (s) -- > 2KCl (s) + 3 O_2[/tex]
The mole ratio of potassium chlorate to oxygen is 2:3.
Mole of 0.450 g potassium chlorate = 0.450/122.55
= 0.0037 moles
Equivalent moles of oxygen = 3/2 x 0.0037
= 0.0056 moles
Mass of 0.0056 moles oxygen = 0.0056 x 32
= 0.1792 g
Percent yield = 0.156/0.1792 x 100
= 87.05%
In other words, the mass of aluminum metal that reacts in the first reaction would be 0.9017 g while the percent yield of the second reaction is 87.05%.
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After centrifugation of the sample, the student was not careful and some of the solid was transferred to the Erlenmeyer flask along with the liquid (supernatant). How is this mistake expected to affect the mass of the limiting reactant in the unknown mixture used?
The fact that some of the solid was transferred would decrease the mass of the limiting reactant.
What is the limiting reactant?We know that in a chemical reaction, there are at least two substances that are combined in order to give the product of the reaction. We also know that the product that we obtain must be in accordance to the stoichiometry of the reaction.
It is common to see that one of the reactants would be present in a very large amount while the other reactant would be present only in quite a small amount. The reactant that is present in a small amount is said to be the limiting reactant while the one that is present in the large amount is said to be the reactant that is in excess.
Having said this, we know that the mass of the limiting reactant can be obtained from the mass of the solid that is obtained after the reaction.
If we do not take out all of the solid from the centrifuge, the mass would not be accurately weighed and the mass of the limiting reactant would not be accurately determined.
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Select all possible problems associated with using nuclear fusion reactions as an energy source. Nuclear fusion occurs at temperatures of millions of degrees Celsius.Research reactors require more energy to maintain these temperatures than the energy the reaction produces.Nuclear fusion occurs at negative degree Celsius temperatures to create unstable reactions to use as an energy sourceIt is difficult to contain the fusion reaction under such extreme conditions.
Answer:
[tex]A,B\text{ and D}[/tex]Explanation:
Here, we want to select the possible problems with nuclear fusion
Nuclear fusion refers to a nuclear reaction wherein two or more daughter nuclei combines to give a larger nucleus
Let us look at the options one after the other to check which of them is correct
a) This is correct
The temperature accompanying nuclear reactions is millions of degrees celsius which are very high
b) This is Correct
This is the major reason why there are currently no nuclear reactors that use fusion to provide energy
c) This is wrong
They occur at very high temperatures. The nuclei need very high energy to send them into kinetic motion
d) This is correct
It is quite difficult to contain a fusion reaction due to the conditions surrounding it and that is one of the reasons why there are no commercial nuclear reactors that use fusion as an energy source
What is the answer for this? I know how to solve it but want to make sure it is correct? (Number 9)
The IUPAC name of the structure (9) is 4-ethyl-2,3-dimethyl-heptane.
What are the steps of IUPAC nomenclature?The first step is to select the longest, most substituted carbon chain containing a functional group is chosen. Then the identification of the primary suffix indicates the degree of saturation such as 'ane' or 'ene.
Then the identification of the secondary suffix indicates the functional group present in the molecule which depends on the number of occurrences of the same functional group such as di. tri tetra etc. Carbon atoms in the carbon chain are numbered from the reactive end of the molecule where the functional group is present.
In the given structure the longest carbon chain of seven carbon atoms. The methyl groups are present at the second and third position and the ethyl group is present at the fourth position. All the bonds in the structure are single bonds so the suffix is 'ane'. Therefore, the IUPAC name is 4-ethyl-2,3-dimethyl-heptane.
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4. You have 500 grams of MgF2. If a 3 M solution is desired, how many Liters must be present?
They give us the grams of solute and the molarity of the solution. To find the liters we must take into account the definition of molarity. Molarity is defined as:
[tex]Molarity=\frac{MolesSolute}{Lsolution}[/tex]The definition of molarity asks us for the moles of solute, so we must pass the grams that give us to moles. For them, we divide the 500 grams by the molar mass of MgF2. The molar mass of MgF2 is 62.3018g/mol.
The moles of MgF2 will be:
[tex]\begin{gathered} molMgF_2=GivengMgF_2\times\frac{1molMgF_2}{MolarMass,gMgF_2} \\ molMgF_2=500gMgF_2\times\frac{1molMgF_2}{62.3018gMgF_2}=8.03molMgF_2 \end{gathered}[/tex]Now, we find the liters of solution:
[tex]\begin{gathered} Lsolution=\frac{MolesSolute}{Molarity} \\ Lsolution=\frac{8.03mol}{3M}=\frac{8.03mol}{3mol/L} \\ Lsolution=3L \end{gathered}[/tex]Answer: It must be present 3L of solution
Select the correct answer.
Consider an atom that has an electron in an excited state. The electron falls to a lower energy level. What effect does that have on the electron?
The electron releases energy in the form of light.
Hope this helps!
Balance the equation
type your answer...
Previous
H₂+ type your answer...
O2 type your answer...
H₂O
The balanced equation
2H2 +O2 =====> 2H2O
What is balanced equation ?
An equation for a chemical reaction is said to be balanced if both the reactants and the products have the same number of atoms and total charge for each component of the reaction. In other words, both sides of the reaction have an equal balance of mass and charge.
The balanced equation
2H2 +O2 =====> 2H2O
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The mass number of an atom containing 37 protons, 50 neutrons,and 37 electrons is:A)13B)50C)37D)87
The question requires us to determine the mass number of an atom with 37 protons, 50 neutrons and 37 electrons.
The atomic number of an atom is determined by its number of protons, while the mass number of an atom is defined as the sum of number of protons and number of neutrons.
Therefore, we can calculate for the atom given by the question:
[tex]\begin{gathered} \text{mass number = number of protons + number of neutrons} \\ \text{mass number = 37 + 50} \\ \text{mass number = 87} \end{gathered}[/tex]Therefore, the mass number of this atom is 87 and the best option to answer the question is letter D.
In paragraph format explain how the energy from Sun gets heats the water in tank. The explanation is based on the concept of atoms (or particles) of matter and the heat transfer (conduction, convection and radiation)
The energy from the sun heats up the water in the tank by convection and radiation.
What is heat transfer?We know that heat is that which is able to effect a temperature change in an object. Now, we know that there are three forms of heat transfer and these are;
1) Conduction
2) Convection
3) Radiation
Now, we know that radiation is the movement of heat without a medium of propagation. Heat from the sun reaches the tank by radiation. The molecules that are at the surface are first heated up and sink down while the heavier particles below move up. This is called convection.
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The______of photosynthesis are the____of cellular respirationmeaning their equation are the ame but_____of each other.
Answer:
reactants /products, products / reactants, opposite / inverse
I can't exactly tell how many underscores there are.
Explanation:
This is biology, but it does contain chemistry.
Determine which of the following electron configurations are not valid:
1.) 1s²2s²2p 3s 3p 4s²4d¹04p5
2.) 1s²2s²2p 3s³3d5
3.) [Ra] 7s²5f8
4.) [Kr] 5s24d105p5
The electron configurations that are not valid among the options are 1s²2s²2p 3s 3p 4s²4d¹04p5 and 1s²2s²2p 3s³3d5. Options 1 and 2.
Electron configurationsThe electron configuration of atoms using the various orbital levels follows the order: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p.
Also, according to Afbau principle, orbitals with low energy levels are filled with electrons before orbitals with higher energy levels.
Using the above, 1s²2s²2p 3s 3p 4s²4d¹04p5 is incorrect for some reasons:
4d, a higher energy level orbital, comes before 4p. 3s and 3p, lower energy level orbitals have no electrons in them while higher energy level orbitals have electrons in them.1s²2s²2p 3s³3d5 is incorrect because:
a lower energy level orbital, 2p is not filled before a higher energy orbital, 3s.3p and 4s orbitals should come before 3d orbital.The remaining electron configurations are correct with correctly placed electrons in the various orbitals.
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What is Kb for the conjugate base of HF (Ka = 6.8 × 10⁻⁴)?
The Kb for the conjugate base of HF, Fluoride ion is 1.470588 * 10^-11
The conjugate base of HF (hydrofluoric acid) is fluoride ion, F-
Ka of HF or hydrofluoric acid is given as 6.8 × 10⁻⁴
Kw = Ka * Kb
Where,
Kb = Base dissociation constant
Kw = Water dissociation constant or equilibrium constant
Ka = Acid dissociation constant
Kw = [H+] [OH-] = 1.0 X 10-14 at room temperature
The formula can be rewritten as,
Kb = (Kw / Ka)
= (10^-14) / (6.8 * 10^-4)
= 1.470588 * 10^-11
Therefore, the kb for the conjugate base of HF, Fluoride ion is 1.470588 * 10^-11
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A gas mixture contains 1.26 g N2 and 0.76 g O2 in a 1.51 L container at 11 C. Calculate the partial pressure of N2?
When we have a mixture of gases, the pressure exerted by each depends on the number of moles present in the mixture, this contribution is called partial pressure. The sum of the partial pressures will be equal to the total pressure, this is called Dalton's law.
Partial pressure can be described by the following equation:
[tex]P_i=X_iP_T[/tex]Where,
Pi is the partial pressure
Xi is the molar fraction
Pt is the total pressure
The molar fraction is calculated by the following equation:
[tex]X_i=\frac{n_i}{n_T}[/tex]Where,
ni is the number of moles of the substance
nT is the total number of moles.
So, we have to find first the number of moles of each gas. We are given the grams of gases, to get the equivalent moles we must divide the mass by the molar mass.
Molar Mass N2=28.0134g/mol
Molar Mass O2=31.9988g/mol
[tex]\begin{gathered} molN_2=1.26g\times\frac{1molN_2}{28.0134gN_2}=0.045molN_2 \\ molO_2=0.76gO_2\times\frac{1molO_2}{31.9988gO_2}=0.024molO_2 \end{gathered}[/tex]Now, the partial pressure of N2 will be:
[tex]P_{N2}=\frac{0.045molN_2}{0.045molN_2+0.024molO_2}\times P_T[/tex][tex]P_{N2}=\frac{0.045molN_2}{0.069mol}\times P_T[/tex][tex]P_{N2}=0.652\times P_T[/tex]If we assume that the gas behavior is like an ideal gas, we can find the total pressure with the following equation:
[tex]\begin{gathered} PV=nRT \\ P_T=\frac{nRT}{V_T} \end{gathered}[/tex]Where,
n is the total number of moles, 0.069mol
R is a constant, 0.08206atm.L/mol.K
V is the volume of the gas, 1.51L
T is the temperature of the gas, K.284.15K
We replace the known data:
[tex]P_T=\frac{0.069mol\times0.08206\frac{atm.L}{mol.K}\times284.15K}{1.51L}=1.06atm[/tex]Now, the partial pressure of nitrogen will be:
[tex]P_{N2}=0.652*1.06atm=0.69atm[/tex]Answer: The partial pressure of N2 is 0.69atm
How can the bulk properties of a substance (macroscopic) such as electrical conductivity be caused by the microscopic such as electrical forces in the atoms?
The bulk properties of a substance (macroscopic) such as electrical conductivity can be caused by the microscopic such as electrical forces in the atoms through the movement of free electrons.
What is Conductivity?This is referred to as the measure or the degree in which a substance conducts electricity and how the electric current moves within a substance.
The electrical conductivity which is macroscopic can be caused by the microscopic such as electrical forces as a result of the electrons moving in the body. The movement of the electron is usually from the negative to the positive terminal of the body.
Read more about Conductivity here https://brainly.com/question/24943129
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