Answer:
Explanation:
the answer is D
Answer:
D
Explanation:
capillaries veins and arteries
Which statement best describes a weak base in solution?A. The base forms a concentrated solution.B. The base dissociates completely.C. The base forms a dilute solution.D. The base dissociates slightly.
Answer:
[tex]D[/tex]Explanation:
Here, we want to get the definition of a weak base
A weak base is a base that does not dissociate completely in solution.
What this means is that when the base is placed in a solution, its dissociation into the corresponding metallic and hydroxide ions is incomplete
Find the percentage by mass of I in CaI2 if it is 13.6% Ca by mass. (Round your answer to one decimal place.) %
First, we have to remember what a mass percentage means (in this particular case):
It is the amount of each element in a compound, and it is calculated as follows:
[tex]\%\text{ m/m = }\frac{mass\text{ of the element}}{mass\text{ of the compound}}*100\text{ }[/tex]The addition of the different mass percentages is equal to 100%.
In this case, we have the percentage of one of the elements of the compound, we can make the respective subtraction:
[tex]\%I\text{ = 100 - 13.6 = 86.4 \%}[/tex]Then, the answer is that the iodine mass percentage is 86.4%
Calculate the frequency of light that has a wavelength of 6.2 * 10^-7 m.
Answer:
4.839 × 10^14 Hz or s^-1
Explanation:
speed of light = wavelength times frequency
frequency = speed of light ÷ wavelength
3.00 x 10^8 = speed of light
3.00 x 10^8 m/s ÷ 6.2 x 10^-7 m = 4.839 × 10^14 Hz or s^-1
socraticorg
What is the Lewis Structure for NH4+?
The Lewis Structure for NH₄⁺ (Ammonium ion) is described as having four sigma bonds around a Nitrogen Atom. It is also to be noted tha there is a +1 charge on the Nitrogen atom.
What further describes the NH₄⁺ (Ammonium ion) Lewis Structure?The nitrogen atom is surrounded by four sigma bonds. As a result, the form of NH4+ is tetrahedral. The total number of sigma bonds and lone pairs surrounding the nitrogen atom is four. As a result, the geometry should be tetrahedral.
Lewis structures also referred as Lewis dot formulas, Lewis dot frameworks, electron dot structures, or Lewis electron dot structures, are schematics that depict the bonding between atoms in a molecule as well as any lone pairs of electrons that may occur.
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how many molecules are there in 2.13 moles of sodium bromide
Answer:
121 I think not sure tbh......
Carbon dioxide gas can be pumped into coal seams underground to release trapped methanegas. Calculate the molar volume of carbon dioxide gas at 700 °C and 6500 kPa
Answer:
Explanation:
Here, we want to get the molar volume of the gas
At STP, 1 mole of a gas occupies a volume 0f 22.4 dm^3
The conditions at STP are 273K
Which of the following is used to find the mass of 3.2 moles of calcium carbonate?
1) Converting grams to moles or moles to grams
In order to do this kind of conversion, we need the molar mass (in grams) of the compound to use it as a conversion factor as follows:
[tex]\frac{molarmassofthecompound_{}}{1molofthecompound_{}}[/tex]-
The isomerization of methyisocyanide, CH3NC, to acetonitrile, CH3CN, is a first-order reaction. If 2.56 mg of CH3NC is present initially, and 1.89 mg is present after 474 min at 230 °C, what is the value of the rate constant, k?Assume the volume is constant. min-1
To solve this question we will use the integrated rate late law for first order reaction:
[tex]\begin{gathered} ln[A]=-kt+ln[A]_0 \\ [A]:concentration\text{ }of\text{ }A\text{ }at\text{ }certain\text{ }time=1.89mg \\ k:rate\text{ }constant=x \\ t:time=474\text{ }mins \\ [A]_0:initial\text{ }concentration=2.56mg \end{gathered}[/tex]By substituting the values we have to determine the unknown we get:
[tex]\begin{gathered} ln1.89=-k\times474min+ln2.56 \\ \frac{0.637-0.940}{-474min}=k \\ k=6.392\times10^{-4}\text{ }min^{-1} \end{gathered}[/tex]Answer: Rate constant k is 6.392x10^-4 per min.
What wavelength (in nm) of light is emitted when an electron transitions from the n = 12 to the n = 1 state?
The wavelength of the light in this case is 92 nm
What is the Bohr model?In accordance with the Bohr model of the atom, We know that electrons could be promoted from the from a lower to a higher energy level. As such, the movement of the electron would lead to the emission of light of a characteristic wavelength.
Hence;
1/λ = 1.097 * 10^7 (1/[tex]n_{2} ^{2}[/tex] - 1/[tex]n_{1} ^{2}[/tex])
Hence;
n1 = 1
n2 = 12
We then have;
1/λ = 1.097 * 10^7 (1/1^2 - 1/12^2)
1/λ = 1.097 * 10^7 (1 - 0.0069)
λ = 9.2 * 10^-8 m or 92 nm
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Please if you could even help with one
The chart of given following ion is
Protons Electrons Neutrons
1) 6 2 8
2) 6 2 7
3) 8 10 9
4) 8 10 8
What are sub atomic particles ?Simply put, a subatomic particle is a particle that is smaller than an atom. Protons, electrons, and neutrons are the three subatomic particles that may typically be separated from an atom.
A neutral atom has the same number of protons and electrons as protons. The sum of the protons and neutrons in the atom's nucleus determines its mass, which is denoted by the letter M. The number of neutrons is equal to the discrepancy between the atomic number and the mass number of the atom (M) (Z).Learn more about Sub atomic particles here:
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PLEASE HELP ME!!!
A)Nuclear fusion releases protons and neutrons, so the total number of protons
and neutrons in a star changes throughout its life.
B)Nuclear fusion conserves protons and neutrons, so the total number of protons
and neutrons in a star changes throughout its life.
C)Nuclear fusion releases protons and neutrons, so the total number of protons
and neutrons in a star remains the same throughout its life.
D)Nuclear fusion conserves protons and neutrons, so the total number of protons
and neutrons in a star remains the same throughout its life.
A)Nuclear fusion releases protons and neutrons, so the total number of protons and neutrons in a star changes throughout its life is the true statement.
What are some uses for nuclear fusion?A suggested method of producing energy would use heat from nuclear fusion processes to produce electricity. A heavier atomic nucleus is created by the fusion of two lighter ones, which also produces energy. Fusion reactors are devices created to use this energy.
Nuclear fusion is less risky than nuclear fission because the fuel rods produced by nuclear fission include dangerous radioactive waste that may be used in weapons and must be maintained carefully for thousands of years.
Powering the Sun and other stars are nuclear fusion processes. Two light nuclei combine to produce one heavy nucleus during a fusion process. The resultant single nucleus's total mass is less than the mass, which causes the process to release energy.
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4) Mixtures of He and oxygen are used in scuba diving to help prevent “TheBends". For a particular dive the total pressure in the tank is 15 atm. If thepartial pressure of oxygen is 6.0 atm, what is the partial pressure of He ?A
By following Daltons laws of partial pressure .
" the pressure that eachgaswould have exerted ,Add up to the total pressure" .
• Therefore :
,• Total Pressure = P.Pressure (oxygen) + P.Pressure of (He)
15 atm = 6atm + Pressure of He
P.Pressure ofHe = 15atm-6atm
= 9 atm
This means that the partial pressure of He = 9atm +
If 30.7 g of C₂H₅OH (MM = 46.07 g/mol) are added to a 500.0 mL volumetric flask, and water is added to fill the flask, what is the concentration of C₂H₅OH in the resulting solution?
The concentration of C₂H₅OH in the resulting solution is 1.332 M.
given that :
mass of C₂H₅OH = 30.7 g
molar mass =46.07 g/mol
volume = 500 ml = 0.5 L
number of moles can be calculated by the following formula :
number of moles = mass / molar mass
no. of moles = 30.7 g / 46.07 g/mol
no. of moles = 0.666 mol
now, the concentration of C₂H₅OH :
Molarity = no. of mole / volumes in l
Molarity = 0.666 / 0.5
Molarity = 1.332 M
Thus, If 30.7 g of C₂H₅OH (MM = 46.07 g/mol) are added to a 500.0 mL volumetric flask, and water is added to fill the flask, The concentration of C₂H₅OH in the resulting solution is 1.332 M.
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What type of evidence does this image BEST represent?
An imprint of a shoe sole on soil.
A.
trace evidence
B.
biological evidence
C.
ammunitions evidence
D.
impression evidence
Answer:
the answer is A since the foot is printed
Answer:
It represents a trace evidence,since it leads to a suspect
The table below gives the equilibrium concentrations for this reaction at acertain temperature:N₂(g) + O₂(g) →→→→2NO(g)0.69 M[N₂]0.98 MOA. 20OB. 1.7 x 10-3OC. 5.0 × 10-2OD. 9.9[0₂]What is the equilibrium constant for the reaction?0.034 M[NO]
Option B is correct
[tex]1.7\times10^{-3}[/tex]Explanations:Given the chemical reaction below;
[tex]N_2(g)+O_2(g)\rightarrow2NO(g)[/tex]The equilibrium constant for the reaction is given as;
[tex]k=\frac{[NO]^2}{[O_2][N_2]}[/tex]Given the following parameters
[tex]\begin{gathered} [NO]=0.034M \\ [N_2]=0.69M \\ [O_2]=0.98M \end{gathered}[/tex]Substitute
[tex]\begin{gathered} k=\frac{(0.034)^2}{(0.69)(0.98)} \\ k=\frac{0.001156}{0.6762} \\ k=0.001709=1.7\times10^{-3} \end{gathered}[/tex]Therefore the equilibrium constant for the reaction is 1.7 * 10^-3
In the reaction below, if a total of 10.0 g of zinc and hydrochloric acid react completely, what is the total mass of zinc chloride and hydrogen produced?Zn(s) + 2HCl(aq) to ZnCl2(aq) + H2(g)Exactly 10.0 gLess than 10.0 gNot enough information to tellGreater than 10.0 g
Answer:
Not enough information to tell.
Explanation:
What is given?
Mass of Zn = 10.0 g,
Mass of HCl = 10.0 g,
Molar mass of Zn = 65.4 g/mol,
Molar mass of HCl = 36.4 g/mol,
Molar mass of ZnCl2 = 136.2 g/mol,
Molar mass of H2 = 2 g/mol.
Step-by-step solution:
First, let's convert 10.0 g of each reactant to moles using their respective molar mass:
[tex]\begin{gathered} 10.0\text{ g Zn}\cdot\frac{1\text{ mol Zn}}{65.4\text{ g Zn}}=0.153\text{ moles Zn,} \\ \\ 10.0\text{ g HCl}\cdot\frac{1\text{ mol HCl}}{36.4\text{ g HCl}}=0.275\text{ moles HCl.} \end{gathered}[/tex]Now, let's identify what is the limiting reactant. Let's see how many moles of ZnCl2 can be produced by 0.153 moles of Zn if 1 mol of Zn reacted produces 1 mol of ZnCl2, and how many moles of ZnCl2 can be produced by 0.275 moles of HCl if 2 moles of HCl reacted produces 1 mol of ZnCl2:
[tex]\begin{gathered} 0.153\text{ moles Zn}\cdot\frac{1\text{ mol ZnCl}_2}{1\text{ mol Zn}}=0.153\text{ moles ZnCl}_2, \\ \\ 0.275\text{ moles HCl}\cdot\frac{1\text{ mol ZnCl}_2}{2\text{ moles HCl}}=0.138\text{ moles ZnCl}_2. \end{gathered}[/tex]You can realize that the limiting reactant, in this case, is HCl because is the first reactant consumed first and this reactant 'impose' the limit to produce the products.
So now, let's find how many moles of H2 are being produced by 0.275 moles of HCl if 2 moles of HCl reacted produces 1 mol of H2:
[tex]0.275\text{ moles HCl}\cdot\frac{1\text{ mol H}_2}{2\text{ moles HCl}}=0.138\text{ moles H}_2.[/tex]The final step is to convert each number of moles of each product to grams using their respective molar mass, as follows:
[tex]\begin{gathered} 0.138\text{ moles ZnCl}_2\cdot\frac{136.2\text{ g ZnCl}_2}{1\text{ mol ZnCl}_2}=18.8\text{ g ZnCl}_2, \\ \\ 0.138\text{ moles H}_2\cdot\frac{2\text{ g H}_2}{1\text{ mol H}_2}=0.276\text{ g H}_2. \end{gathered}[/tex]We're producing 18.8 g of zinc chloride (ZnCl2), and 0.276 g of hydrogen (H2), so based on this logic the answer would be not enough information to tell.
Arrhenius base produces which ion in solutionGroup of answer choiceshydrogen ionshydroxide ionsneitherboth
An Arrhenius base is a compound which ionizes to yield hydroxide ions (OH−) in aqueous solution.
2.75 grams of Potassium represent how many grams of Potassium?Group of answer choices39.10 grams107.5 grams14.22 grams215 grams
Solutions :
We are given
• mass of potassium = 2.75 g
,• Recall that 1 mole of potassium = 39.0983 grams
So , 2.75 g will represent
[tex]\begin{gathered} If\text{ 1 mole K : 39.0983 grams } \\ \text{then 2.75 mol : x } \\ \therefore\text{ x grams = (2.75 moleK }\cdot\text{ 39.0983 g) / 1 mole K } \\ \text{ = 107.52 grams } \end{gathered}[/tex]This means that 2.75 moles of Potassium represent 107.52 grams of potassium.2A + C + D + EDetermine the enthalpy(AH)in kJ of the above reaction using the reactions below:1B → C AH = 415.3 kJA + 1B →D AH = -95.7 kJ6A ->6E AH = 207.9 kJ
Explanations:
• We will follow Hess's Law of Constant Heat Summation:
(that states that if a reaction occurs in more than one route, then the the total enthalpy change for the reaction is the sum of all changes.)
For reaction :
[tex]\begin{gathered} B\Rightarrow C\text{ }\Delta H\text{ = 415.3 kJ }\ldots\text{.}\mathrm{}(\text{ reaction 1)} \\ A+B\text{ }\Rightarrow\text{ D }\Delta H\text{ = -95.7kJ}\ldots.(\text{ reaction 2 ) } \\ 6A\text{ }\Rightarrow6E\text{ }\Delta H\text{ = 207.9kJ }\ldots\ldots(\text{reaction 3 ) } \end{gathered}[/tex]∆H total =( reaction 3 )/6 +reaction 2 - reaction 1this can be expressed as :
[tex]\begin{gathered} \Delta H_{total\text{ }}=\text{ }\frac{207.9}{6\text{ }}+(-95.7\text{ ) - 415}.3\text{ } \\ \text{ = 34.65 -95.7 -415.3} \\ \text{ =-476.35kJ} \end{gathered}[/tex]This means that ∆H total= -476.35kJ.
What will be the final temperature of a 3L nitrogen gas initially exposed to a temperature of 10°C if the volume is increased to 10L assuming that the pressure is fixed at 1 atm?
Step 1
Charles's law states that the volume (V) of a gas is directly proportional to its absolute temperature. It is assumed that the pressure and the quantity of gas remain constant.
Mathematically:
[tex]\frac{V1}{T1}=\frac{V2}{T2}[/tex]-------------------
Step 2
Information provided:
T1 = 10 °C + 273 = 283 K
V1 = 3 L
---
T2 = Unknown
V2 = 10 L
-------------------
Step 3
Procedure:
[tex]\begin{gathered} \frac{V1}{T1}=\frac{V2}{T2} \\ T2\text{ =}\frac{V2}{V1}\text{ x T1} \\ T2\text{ = }\frac{10\text{ L}}{3\text{ L}}\text{ }x\text{ }283\text{ K } \\ T2\text{ = 943 K} \end{gathered}[/tex]Answer: 943 K or 670 °C
A certain first-order reaction is 46% complete in 45 s. What are the values of the rate constant and the half-life for this process?
The rate constant ( k )= 9.2 x 10⁻³ s⁻¹The half life (t1/2 )= 75.3 s
It is given that the reaction is 46% complete in 45 s
The relation between rate constant and the half life can be shown as:
For first order reaction:
ln[A]=−kt+ln[A]o
46% complete, 54% remains
A = 0.54
Ao = 1
Put the value of given data in the formula:
ln A = -kt + ln Ao
ln 0.54 = -k.45 + ln 1
-0.616=-k.45
k = 13.6 x 10⁻³ s⁻¹
The half life can be determined by using the formula:
t1/2 = (ln 2) / k
t1/2 = 0.693 / 13.6 x 10⁻³
t1/2 = 0.0509 ×10⁻³ s.
t1/2 = 5.09 ×[tex]10^{5}[/tex] s.
Therefore, the rate constant for the first order reaction will be 13.6 x 10⁻³ s⁻¹ and half life will be 5.09 ×[tex]10^{5}[/tex] s.
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A dog
walks along the ground. If
the dog applies an action
force on the ground, what is
the reaction force?
Action and response are two forces that have the same magnitude but opposing directions.
Explanation.
The force used by a dog as it moves across the ground is known as the action force. The force that the earth exerts on the dog is the reaction force, on the other hand. Newton's third law of motion serves as its foundation.
What does walking on the ground include action and reaction force?When we walk on the ground, we push the earth backward with our feet, but the ground pushes our feet forward with an equal force, which propels us forward. Because of this, the action is the force that pushes the ground backward, and the reaction is the force by the ground on our feet.
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A NaOH solution contains 26.0 g of NaOH, and it’s concentration is 1.3M. What is its volume?
Answer
Volume = 0.5 L
Explanation
Mass of NaOH = 26.0 g
Molarity = 1.3 M
Molar mass of NaOH = 39.997 g/mol
Volume = ?
The volume of NaoH can be calculated using
[tex]\begin{gathered} V=\frac{n}{M} \\ \text{Where;} \\ V\text{ is the volume} \\ n\text{ is the number of mole of NaOH} \\ \text{M is the Molarity} \end{gathered}[/tex]But the number of mole of NaOH, n = mass of NaOH / Molar mass of NaOH
[tex]\Rightarrow n=\frac{26.0\text{ g}}{39.997\text{ g/mol}}=0.65\text{ mole}[/tex]Therefore, the volume of NaOH is
[tex]V=\frac{0.65}{1.3}=0.50\text{ L}[/tex]Chen has a toy car and wants to find out which surface will allow the car to move the fastest. He plans to push the car on carpet, wood, and bricks. predict which surface the toy car will move the fastest on and why
Answer:
The car will most likely move the fastest on the wood. Carpet will create drag due to the friction between the car's wheels and the carpet. Bricks are not smooth so drag will occur, however it will be minimal. Wood is usually smooth and there is almost no drag or friction...the car will glide easily over the surface.
Explanation:
Hope this helps!!
Multiply or divide the following measurements. Be sure your answer You and your contains the correct significant digits. 827.76 divided 60.65 s = m/s685.5 mol divided 0.50 L = mol/L20.9476 cm x 26. Cm = cm^2
827.76 m/60.65 s = 13.65 m/s
685.5 mol/0.50 L = 1371 mol/L
20.9476 cm x 26 cm = 545 cm^2
When adding/subtracting
Use the least number of significant figures past the decimal point when adding or subtracting numbers.
When multiplying/dividing
Use the least number of significant figures present in any number in the problem when multiplying or dividing numbers.
What is the total energy required to break all the bonds in 1 mol hexane C6H14?A) 760 kJB) 5780 kJC) 1740 kJD) 7520 kJ
The total energy to break the hexane bonds will be equal to the sum of each of the energy to break each bond.
So the first thing we're going to do is determine how many and what type of bonds hexane has. Hexane is an alkane, meaning the C-C bonds are all single bonds. We also have C-H bonds. According to the structure of hexane, we will count each of the bonds in the following figure:
The number of C-H bonds is written in blue, we see that there are 14 C-H bonds, which coincides, being an alkane, with the number of hydrogen atoms.
The number of C-C bonds is written in orange. The number of C-C bonds is equal to 5.
Now, we multiply the energy to break each bond by the number of bonds and add the energy of the C-H and C-C bonds.
[tex]TotalEnergy=14\times Energy(C-H)+5\times Energy(C-C)[/tex][tex]\begin{gathered} TotalEnergy=14\times413kJ/mol+5\times347kJ/mol \\ TotalEnergy=7517kJ/mol \end{gathered}[/tex]So, for 1 mol of hexane the energy. required to break all the bonds will be 7514kJ
Answer: The closest value to the answer is 7520. D) 7520 kJ
Could you please tell me that is true or false Surfactants are compounds that increase surface tension of a solvent.
Surfactants are characterized to lower the surface tension between two liquids or between a liquid and a gas and so on.
You can see an example for detergents: the detergents are surfactants that lower the surface tension and that's because you can see that the dirt disperses easily and other substances, so the answer is false.
Calculate the boiling point of a 0.33 m solution of a solute in benzene.
(Kb = 2.53°C /m).
We can see that the solution has a boiling point of 80.93°C.
What is the boiling point?The atmospheric pressure does equal the pressure of a liquid as we heat the system. The temperature at which this occurs is called the boiling point. Now we know that the boiling point of the pure benzene is 80.1 °C.
Given that;
ΔT = K m i
ΔT = boiling point elevation
K = boiling point constant
m = molality of the solution
i = Van Hoff factor (molecular solute)
ΔT = 2.53°C /m * 0.33 m * 1
ΔT = 0.83°C
The boiling point of the solution is now gotten from ; 0.83°C + 80.1 °C
= 80.93°C
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Use the chemical equation to answer the questionCo(H0+4Cr+heat CoCl₂ + 6H₂OCobalt ions form complex ions with water and chloride. The Co(H₂O) ions are pink, and the CoCions are blue. A scientist creates a solution that is purple at equilibrium. How can thescientist make the solution more pink?(2 point)O by adding hydrochloric acid (HCI)Oby adding Co(H₂O) ionsO by adding water (H₂O)
Answer
By adding water (H2O)
Explanation
In this reaction, water is a product, adding the product will favour the reverse reaction, which is the formation of more Co(H2O)6^2+.
The
following reaction: Na+ (g) --> Na+ (aq) AH = -364 kJmol
1 is endothermic reaction.
True
False
Na+ (g) --> Na+ (aq) AH = -364 kJmol 1 is endothermic reaction. The given reaction is False, As H is negative hence exothermic reaction not endothermic
What is endothermic reaction?
Chemical processes referred to as endothermic reactions occur when the reactants take in heat energy from their environment to create products. These reactions produce a cooling effect by bringing the temperature of the space around them down. Ice cubes absorb heat energy from their surroundings and melt to generate liquid water as an example of an endothermic physical process (no chemical bonds are broken or formed).
False, As H is negative hence exothermic reaction not endothermic
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