Answer:
Its b its the state not anything else
A physical change has occurred has occurred when evaporating water producing gaseous water as a physical change results in a phase change, not a change in composition.
What is a physical change?
Physical changes are defined as changes which affect only the form of a substance but not it's chemical composition. They are used to separate mixtures in to chemical components but cannot be used to separate compounds to simpler compounds.
Physical changes are always reversible using physical means and involve a change in the physical properties.Examples of physical changes include melting,boiling , change in texture, size,color,volume and density.Magnetism, crystallization, formation of alloys are all reversible and hence physical changes.
They involve only rearrangement of atoms and are often characterized to be changes which are reversible.
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3 examples of electrochemical cell
Which statements describe functions of DNA? Select three options.
Answer:
The function of DNA is to store all of the genetic information that an organism needs to develop, function, and reproduce. Essentially, it is the biological instruction manual found in each of your cells. The instructions in DNA are written in a simple alphabet that has just four letters—A, T, C, and G.
Explanation:
Answer:
It is ABD
Explanation:
Which element will reduce Mg2+ to Mg?
a) Fe b) Ba c) Pb d) Ag
Answer:
Ba
Explanation:
Let us consider the electrode potential of one of the options listed in the question,
Ba2+(aq) + 2 e- -----> Ba(s). -2.90V
It is very important to recall that a metal can only displace another metal from aqueous solution if that metal has a more negative reduction potential that the metal it displaced. This implies that if there are two metals A and B, A can only displace B from an aqueous solution of B if A has a more negative reduction potential than B.
The reduction potential of Mg^2+ is -2.37V. This is less negative than that of Ba^2+ which is -2.90V. Hence barium can reduce Mg^2+ to metallic Mg.
What are the two isomers of ethene
Answer:
These are called cis-but-2-ene (where the groups are on the same side) or trans-but-2-ene (where they are on opposite sides). Cis-but-2-ene is also known as (Z)-but-2-ene; trans-but-2-ene is also known as (E)-but-2-ene. For an explanation of the two ways of naming these two compounds, follow the link in the box below.
Explanation:
In a chemical equation, which symbol should be used to indicate that a substance is in solution?
(s)
(g)
оооо
(ag)
Answer: In a chemical equation, (aq) should be used to indicate that a substance is in solution.
Explanation:
The chemical reaction is represented by putting the reactants at left side of the arrow and products on the right side of the arrow. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.
The liquids are designated by symbol (l) and gases are designated by symbol (g).
In a chemical equation, (aq) should be used to indicate that a substance is in solution.
Answer:
D (aq)
Explanation:
On Edge
how many molecules are there in 125 grams of sugar, C12H22O11
Answer:
A molecule of sucrose (C12H22O11) has 12 carbon atoms, 22 hydrogen atoms and 11 oxygen atoms. The subscripts also indicate the ratios of the elements.
Explanation:
This is because it has the abbreviation of the Carbon atoms, Hydrogen atoms, and Oxygen atoms are right before the number.
The number of molecules of sugar is required.
The number of molecules is [tex]2.2\times 10^{23}\ \text{molecules}[/tex]
m = Mass of sugar = 125 g
[tex]N_A[/tex] = Avogadro's number = [tex]6.022\times 10^{23}\ \text{mol}^{-1}[/tex]
Molar mass of sugar
[tex]M=C_{12}H_{22}O_{11}=12\times 12+1\times 22+16\times 11\\\Rightarrow M=342\ \text{g/mol}[/tex]
Number of moles is
[tex]n=\dfrac{m}{M}\\\Rightarrow n=\dfrac{125}{342}\\\Rightarrow n=0.365\ \text{mole}[/tex]
Number of molecules is
[tex]N=N_An\\\Rightarrow N=6.022\times 10^{23}\times 0.365\\\Rightarrow N=2.2\times 10^{23}\ \text{molecules}[/tex]
The number of molecules is [tex]2.2\times 10^{23}\ \text{molecules}[/tex]
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What is the pressure exerted by 2.3 mol of a gas with a temperature of 40. °C and a volume of 3.5 L?
Answer:
16.89 atm.
Explanation:
Step 1:
Data obtained from the question
Number of mole (n) = 2.3 mol
Temperature (T) = 40°C = 40°C + 273 = 313K
Volume (V) = 3.5L
Pressure (P) =..?
Gas constant (R) =0.0821 atm.L/Kmol
The pressure exerted by the gas can be obtained by using the ideal gas equation as shown below:
PV = nRT
Divide both side by V
P = nRT /V
P = 2.3 x 0.0821 x 313 / 3.5
P = 16.89 atm.
Therefore, the pressure exerted by the gas is 16.89 atm.
if 15 mol C is mixed with 10 mol O2 which reactant is the limiting reactant? Which reactant would be the excess reactant?
Answer:
C is the excess reactant.
Explanation:
Reaction is C + O2 --> CO2
1mol of C required to react with 1mol O2
Therefore 15 - 10 = 5moles of C will be in excess
1. Mountains are most likely formed
a. when glaciers melt.
b. from earthquakes.
C. when land sinks.
d. where tectonic plates collide.
How many atoms of each element are in the chemical formula......
CA(OH)2
A.1 calcium, 1 oxygen, and 1 hydrogen
B.1 calcium, 2 oxygen, and 2 hydrogen
C.2 calcium, 1 oxygen, and 2 hydrogen
D.2 calcium, 2 oxygen, and 2 hydrogen
Answer:
Option B. 1 calcium, 2 oxygen, and 2 hydrogen
Explanation:
The number of each atoms present in Ca(OH)2 can be summarised as follow:
Calcium (Ca) = 1
Oxygen (O) = 2
Hydrogen (H) = 2
From the above illustration, we can see clearly that Ca(OH)2 contains 1 calcium, 2 oxygen and 2 hydrogen.
Answer:
1 calcium, 2 oxygen, and 2 hydrogen
1 calcium, 2 oxygen, and 2 hydrogen
1 calcium, 2 oxygen, and 2 hydrogen
1 calcium, 2 oxygen, and 2 hydrogen
1 calcium, 2 oxygen, and 2 hydrogen
1 calcium, 2 oxygen, and 2 hydrogen
1 calcium, 2 oxygen, and 2 hydrogen
XD
Explanation:
Given the formula V=1/3Ah, solve for h.
Answer: h = 1/3VA
Explanation:
V = 1/3Ah
3AhV = 1
h = 1/3VA
Calculate the temperature of a 0.50 mol sample of a gas at 0.987 atm and a volume of 12 L.
-7 C
11 C
15.5 C
288 C
Answer: [tex]15.5^0C[/tex]
Explanation:
According to ideal gas equation:
[tex]PV=nRT[/tex]
P = pressure of gas = 0.987 atm
V = Volume of gas = 12 L
n = number of moles = 0.50
R = gas constant =[tex]0.0821Latm/Kmol[/tex]
T =temperature = ?
[tex]T=\frac{PV}{nR}[/tex]
[tex]T=\frac{0.987atm\times 12L}{0.0820 L atm/K mol\times 0.50mol}=288.5K=(288.5-273)^0C=15.5^0C[/tex]
Thus the temperature of a 0.50 mol sample of a gas at 0.987 atm and a volume of 12 L is [tex]15.5^0C[/tex]
Name 5 descriptions of a key including mass
Answer:
I'm assuming you're talking about something like a regular housekey, in which case there are numerous things you can describe!
Its mass: how much it weighs, times the gravity of the system.
Its color: is it silver-colored, or gold, etc.?
Its volume: you could probably calculate this, though it would be hard because it's not a traditional shape, I assume.
Its density: this is mass/volume. It means how many of the atoms are in a given space; how tightly packed the atoms are.
Its tendency to rust / its specific combination of metals or alloys: is it made of copper, tin, steel.. and these are all things that can rust to varying degrees.
When K-37 undergoes positron emission, what is the resulting atom?
A) K-37
B) K-38
C) Ar-37
D) Ar-38
Answer:
C) Ar-37
Explanation:
A positron is a positively charged electron. It has the same mass as that of an electron, but opposite charge. It is the counterpart of an electron.
The reaction involving the emission of a positron by k-37 would produce a Ar-37, which is an unstable isotope of Argon. In this emission, there must not be a particle loss or creation, the addition of the mass number and proton number on LHS must be the sane as that on RHS of the equation.
An isotope is ability of an element to exist in two or more forms with the same atomic number but different mass number.
state two importance of soil air to plants
Answer:
Soil contains minerals such as Iron, Zinc, Nitrogen compounds, etc. that are all essential to sustaining life. It also holds water and makes it available for plants to use. Soil also contains ores from which we can extract metals such as iron, copper, gold, and aluminum.
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Which is an example of a beneficial mutation? ANSWER AND ILL GIVE BRAINLY POINTS !!!!!! HELP ASAP !
Answer:
Some humans are randomly immune to malaria or have increased bone density due to random beneficial mutations.
Explanation:
Answer: one that changes the color of a rabbit, allowing it to hide from predators.
Explanation:Hey give me brainliest award need it
Convert 7 mol carbon to grams.
Answer:
84.07grams of carbon in 7 mole of carbon.
Explanation:
7 mol×12.01g/1mol
=84.07g
Un tanque de acetileno para una antorcha de soldadura de oxiacetileno proporciona 9340 L de gas acetileno, C2H2, a 0°C y 1 atm 2CH2H2(g) + 502(g) -> 4CO2(g) + 2H2O(g) ¿Cuántos tanques de oxígeno, cada uno con 7x10³ L de o2 a 0°C y 1 atm, serán necesarios para quemar el acetileno?
Answer:
3.33 tanques de O₂
Explanation:
Basados en la reacción:
2C₂H₂(g) + 5O₂(g) → 4CO₂(g) + 2H₂O(g)
2 moles de acetileno reaccionan con 5 moles de oxígeno produciendo 4 moles de dióxido de carbono y 2 moles de agua
La ley de Avogadro dice que el volumen de un gas bajo temperatura y presión constantes es proporcional a las moles de este gas. Así, como 2 moles de acetileno reaccionan con 5 moles de oxígeno, los litros de O₂ necesarios para quemar 9340L de acetileno son:
9340 L C₂H₂ × (5 moles O₂ / 2 moles C₂H₂) = 23350L de O₂
Si un tanque contiene 7x10³ L de O₂ serán necesarios:
23350L O₂ ₓ (1 tanque / 7x10³L) = 3.33 tanques de O₂
What happens to electrons in ionic bonds?
Answer:
Ionic bonding is the complete transfer of valence electron(s) between atoms. It is a type of chemical bond that generates two oppositely charged ions. In ionic bonds, the metal loses electrons to become a positively charged cation, whereas the nonmetal accepts those electrons to become a negatively charged anion.
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85.0g of barium metal are added to 275ml of 3.55M solution of hydrochloric acid, how many milliliters of hydrogen gas are collected at 18.5oC and 755.5mmHg in this single replacement reaction?
Answer: 0.024 ml of hydrogen gas are collected at [tex]18.5^0C[/tex] and 755.5mmHg in this single replacement reaction
Explanation:
To calculate the moles :
[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]
[tex]\text{Moles of} Ba=\frac{85.0g}{137g/mol}=0.620moles[/tex]
To calculate the number of moles for given molarity, we use the equation:
[tex]\text{Molarity of the solution}=\frac{\text{Moles of solute}\times 1000}{\text{Volume of solution in ml}}[/tex]
[tex]3.55M=\frac{\text{Moles of} HCl\times 1000}{275ml}\\\\\text{Moles of }HCl=\frac{3.55\times 275}{1000}=0.976mol[/tex]
The balanced chemical reaction is:
[tex]Ba+2HCl\rightarrow BaCl_2+H_2[/tex]
According to stoichiometry :
2 moles of [tex]HCl[/tex] require = 1 mole of [tex]Ba[/tex]
Thus 0.976 moles of [tex]HCl[/tex] will require=[tex]\frac{1}{2}\times 0.976=0.488moles[/tex] of [tex]Ba[/tex]
Thus [tex]HCl[/tex] is the limiting reagent as it limits the formation of product and [tex]Ba[/tex] is the excess reagent.
As 2 moles of [tex]HCl[/tex] give = 2 moles of [tex]H_2[/tex]
Thus 0.976 moles of [tex]HCl[/tex] give =[tex]\frac{2}{2}\times 0.976=0.976moles[/tex] of [tex]H_2[/tex]
According to ideal gas equation:
[tex]PV=nRT[/tex]
P = pressure of gas = 755.5 mmHg = 0.994 atm (760 mm Hg = 1 atm )
V = Volume of gas in L = ?
n = number of moles = 0.976
R = gas constant =[tex]0.0821Latm/Kmol[/tex]
T =temperature =[tex]18.5^0C=(18.5+273)K=291.5K[/tex]
[tex]V=\frac{nRT}{P}[/tex]
[tex]V=\frac{0.994atm\times 0.0820 L atm/K mol\times 291.5K}{0.994atm}=24.0L=0.024ml[/tex] (1L=1000ml)
Thus 0.024 ml of hydrogen gas are collected at [tex]18.5^0C[/tex] and 755.5mmHg in this single replacement reaction
2 SO₂ + O₂ → 2 SO₃ + energy This reaction would be considered
Answer:
this is a contact process, and the energy released means it is a exothermic process
6. How much water must be added to 600 mL of a 0.15 mol/L Ca(OH); solution
to make a solution with a concentration of 0.10 mol/L? (4 marks)
Answer:
300mL
Explanation:
To obtain the volume of water added, let us calculate the volume of the diluted solution.
Data obtained from the question include:
Molarity of stock solution (M1) = 0.15mol/L
Volume of stock solution (V1) = 600mL
Molarity of diluted solution (M2) = 0.1mol/L
Volume of diluted solution (V2) =..?
The volume of the diluted solution can be obtained as follow:
M1V1 = M2V2
0.15 x 600 = 0.1 x V2
Divide both side by 0.1
V2 = 0.15 x 600 / 0.1
V2 = 900mL.
Therefore the volume of the diluted solution is 900mL.
Finally, we can obtain the volume of the water added by calculating the difference in the volume of the diluted solution and that of the stock solution. This is illustrated below:
Volume of stock solution (V1) = 600mL
Volume of diluted solution (V2) = 900mL
Volume of water added =...?
Volume of water added = V2 – V1
Volume of water added = 900 – 600
Volume of water added = 300mL
Therefore, the volume of water added is 300mL
A first order reaction has rate constants of 4.6 x 10-2 s-1 and 8.1 x 10-2 s-1 at 0ºC and 20ºC, respectively. What is the value for the activation energy?
A.
0.566 J/mol
B.
2.5 x 10-4 J/mol
C.
2260 J/mol
D.
18,800 J/mol
E.
1.76 J/mol
Answer:
D. 18,800 J/mol
Explanation:
We need to use the Arrhenius equation to solve for this problem:
[tex]k=Ae^{\frac{-E_a}{RT}[/tex], where k is the rate constant, A is the frequency factor, [tex]E_a[/tex] is the activation energy, R is the gas constant, and T is the temperature in Kelvins.
We want to find the value of [tex]E_a[/tex], so let's plug some of the information we have into the equation. The gas constant we can use here is 8.31 J/mol-K.
At 0°C, which is 0 + 273 = 273 Kelvins, the rate constant k is [tex]4.6*10^{-2}[/tex]. So:
[tex]k=Ae^{\frac{-E_a}{RT}[/tex]
[tex]4.6*10^{-2}=Ae^{\frac{-E_a}{8.31*273}[/tex]
At 20°C, which is 20 + 273 = 293 Kelvins, the rate constant k is [tex]8.1*10^{-2}[/tex]. So:
[tex]k=Ae^{\frac{-E_a}{RT}[/tex]
[tex]8.1*10^{-2}=Ae^{\frac{-E_a}{8.31*293}[/tex]
We now have two equations and two variables to solve for. We just want to find Ea, so let's write the first equation for A in terms of Ea:
[tex]4.6*10^{-2}=Ae^{\frac{-E_a}{8.31*273}[/tex]
[tex]A=\frac{4.6*10^{-2}}{e^{\frac{-E_a}{8.31*273}} }[/tex]
Plug this in for A in the second equation:
[tex]8.1*10^{-2}=Ae^{\frac{-E_a}{8.31*293}[/tex]
[tex]8.1*10^{-2}=\frac{4.6*10^{-2}}{e^{\frac{-E_a}{8.31*273}} }e^{\frac{-E_a}{8.31*293}[/tex]
After some troublesome manipulation, the answer should come down to be approximately:
Ea = 18,800 J/mol
The answer is thus D.
Which of these is an Arrhenius base?
A. LiOH
B. NH3
C. H2PO4-
D. CH3COOH
Answer:
LiOH
Explanation:
Among the following LiOH or lithium hydroxide is a Arrhenius base as it increase hydroxide ion concentration of a substrate.
What is a base?
According to the Arrhenius concept, base is defined as a substance which yields hydroxyl ions on dissociation.These ions react with the hydrogen ions of acids to produce salt in an acid-base reaction.
Bases have a pH higher than seven as they yield hydroxyl ions on dissociation.They are soapy in touch and have a bitter taste.According to the Lowry-Bronsted concept, base is defined as a substance which accepts protons .Base react violently with acids to produce salts .Aqueous solutions of bases can be used to conduct electricity .They can also be used as indicators in acid-base titrations.
They are used in the manufacture of soaps,paper, bleaching powder.Calcium hydroxide ,a base is used to clean sulfur dioxide gas while magnesium hydroxide can be used as an antacid to cure acidity.
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Help ! I am stuck on this question please help
what is an atom
plz help
Answer:
the smallest thing in the world
Explanation:
Answer:
It is the smallest particle of the elements that exists ob the earth
An unsaturated solution has,
A. the maximum concentration of solute that can be dissolved into solvent at a specific temperature.
B. a higher concentration of solute that can be dissolved into solvent at a specific temperature.
C. unstable characteristics.
D. a lower concentration of solute than can be dissolved into solvent at a specific temperature.
Answer:
D... I think? Because it is unsaturated so there is more solute than solvent...
What is the name of MnO? Explain how you determined the bond type and the steps you used to determine the naming convention for the compound.
Answer:
Magnesiumoxide
Explanation:
I don't know
Gravity does NOT * 10 points increase when the distance between two objects increases. increase when the distance between two objects decreases. increase when the mass of one object increases. increase when the mass of both objects increases.
Answer:
increase when the distance between two objects increases
Explanation:
when the objects move further apart, the gravitational pull between them becomes weaker, and so the gravity isn't as strong. all of the other options increase gravity
5. What is the primary purpose of muscle?
Answer:
Any type of movement
Explanation:
All muscles are used for any way of movement in the body.