1. Percent yield = (Actual yield/Theoretical yield) x 100
Actual yield = 1.50 g Cu
Theoretical yield = (0.5 f Al) x (1 mol Al/27.0 g Al) x (1 mol Cu/1 mol Al) x (63.5 g Cu/1 mol Cu) = 1.35 g Cu
Percent yield = (1.50 g Cu/1.35 g Cu) x 100 = 111.1%
2. Balanced chemical equation: 2 Al + 3 CuCl2 → 2 AlCl3 + 3 Cu
Answer: 2Al + 3CuCl2 → 2AlCl3 + 3Cu, Percent yield is 84.9%
Explanation: Find moles of aluminum using molar mass then x by coefficient ratio of cu/al. Then divide 1.5 by that value and x 100.
mhanifa, can you answer this question pls?
Solve for x.
1. 5(2x +15) = 55
2. 9(6x +4) = 166
3. 3(8x +20) = 356
Answer:
1. x=-2
2. x=65/27
3. x=37/3
Explanation:
Isolate x
1. Divide by 5: 2x+15=11
2x=11-15
x=-2
2. Distribute: 54x+36=166
54x=166-36
x=130/54
Simplify by dividing by 2: x=65/27
3. Distribute: 24x+60=356
24x=356-60
x=296/24
Simplify by dividing by 8: x=37/3
can you help me with my science
What is the activation energy of a reaction?
A. The energy that is given off when a reaction happens
B. The kinetic energy of the colliding molecules
C. The speed at which the molecules must be moving in order to
react
D. The energy the molecules must have in order to react
SUBMIT
Answer:
D i took it aswell
Explanation:
The energy the molecules must have in order to react. Hence, option D is correct.
What is activation energy?Activation energy is the sufficient amount of energy necessary to initiate a chemical reaction.
It can also be said as the minimum amount of energy needed to energize molecules or atoms so that they can undergo a chemical reaction or transformation.
Hence, the energy the molecules must have in order to react.
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I need help can somebody help me
Answer:
they slow down
Explanation:
Water molecules slow down as they lose energy. The molecules become closer together and decrease the volume.
Trial 12 1.Volume of Acid used ( mL) 2020 2.Molarity of acid used (M) 0.0160.016 3.Initial volume reading of base buret 018.6 4.Final volume reading of base used 18.636.9 5.Volume of base used (4-3, mL) _________ _________ 6.Molarity of base (1*2/5, M) _________ _________ 7.Average molarity of base _________
Answer:
[tex]V_B = 18.3mL[/tex] -- Volume of base used
[tex]M_B = 0.0175M[/tex] --- Molarity of base
Explanation:
Given
[tex]V_A = 20mL[/tex] -- Volume of acid used
[tex]V_B_1 = 18.6mL[/tex] --- Buret Initial reading
[tex]V_B_2 = 36.9mL[/tex] --- Buret Final reading
[tex]M_A = 0.016M[/tex] --- Molarity of the acid
Solving (a): Volume of base used (VB)
This is calculated by subtracting the initial reading from the final reading of the base buret.
i.e.
[tex]V_B = V_B_2 - V_B_1[/tex]
[tex]V_B = 36.9mL - 18.6mL[/tex]
[tex]V_B = 18.3mL[/tex]
Solving (b): Molarity base (MB)
This is calculated using:
[tex]M_A * V_A = M_B * V_B[/tex]
Make MB the subject
[tex]M_B = \frac{M_A * V_A }{V_B}[/tex]
This gives:
[tex]M_B = \frac{0.016M *20mL}{18.3mL}[/tex]
[tex]M_B = \frac{0.016M *20}{18.3}[/tex]
[tex]M_B = \frac{0.32M}{18.3}[/tex]
[tex]M_B = 0.0175M[/tex]
Solving (c): There is no such thing as average molarity
An adaptation is best described as occurring over which time scale? *
(10 Points)
O A. over many eras
O B. over many generations
O C. over one generation
D. over the lifetime of one individual
Answer:
over many eras
Explanation:
In an ecosystem, an adaptation is best described as occurring over many generations.
What is an ecosystem?Ecosystem is defined as a system which consists of all living organisms and the physical components with which the living beings interact. The abiotic and biotic components are linked to each other through nutrient cycles and flow of energy.
Energy enters the system through the process of photosynthesis .Animals play an important role in transfer of energy as they feed on each other.As a result of this transfer of matter and energy takes place through the system .Living organisms also influence the quantity of biomass present.By decomposition of dead plants and animals by microbes nutrients are released back in to the soil.
There are various types of ecosystem present in the environment.
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Consider the reaction between a solution of molecule A and a solid block of molecule B. In general, for a reaction to occur, the reactant molecules must be in contact with each other. Therefore, increasing the frequency of collisions between A and B molecules allows the reaction to occur more quickly. Identify the change in reaction condition that will increase the frequency of the molecular collisions.
Answer:
Decreasing the volume of solvent in the solution of molecule A
Explanation:
We know that one of the factors that affect the rate of reaction is the concentration of the reactants. The greater the concentration of reactants, the faster the rate of reaction (the greater the frequency of collision between reactants).
Hence, when we decrease the volume of solvent in the solution of molecule A, the concentration of the solution increases and consequently more particles of molecule A are available to collide with particles of molecule B resulting in a higher rate of reaction.
The hydrolysis of adenosine triphosphate (ATP) is represented by the equation below. This reaction is critically important in cellular biology, but the reaction itself proceeds at a very slow rate. Based on the information given, which of the following best explains why an enzyme (biological catalyst) is required for the reaction to occur at a faster rate?
ATP+ H2O ADP+ Pi
ΔG= -30.5Kj/mol
a. Because ΔG < 0, the hydrolysis of ATP is not thermodynamically favorable. In cells, ΔS is increased by increasing the amount of H2O consumed, resulting in ΔG >0 and an increase in the reaction rate.
b. Because ΔG < 0, the hydrolysis of ATP is not thermodynamically favorable. In cells, enzymes act as catalysts that decrease ΔH for the reaction, resulting in ΔG >0 and an increase in the reaction rate.
c. Although the hydrolysis of ATP is thermodynamically favorable, without a catalyst the reaction occurs at a very slow rate because it has a small activation energy.
d. Although the hydrolysis of ATP is thermodynamically favorable, without a catalyst the reaction occurs at a very slow rate because it has a large activation energy.
Answer:
d. Although the hydrolysis of ATP is thermodynamically favorable, without a catalyst the reaction occurs at a very slow rate because it has a large activation energy.
Explanation:
Hello!
In this case, since negative Gibbs free energies of reaction stand for thermodynamically favored processes, we can immediately rule out choices a. and b.
Moreover, since the reaction is slow without the presence of a catalyst, which the context of biochemistry is an enzyme, we infer that correct choice is d. Although the hydrolysis of ATP is thermodynamically favorable, without a catalyst the reaction occurs at a very slow rate because it has a large activation energy because the higher the activation energy the slower the reaction according to the Arrhenius equation.
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An attractive force between all objects that have mass is knows as ____________. The more mass, the more of this type of force. The more distance between objects, the less of this type of force.
A. Friction
B. Normal force
C. Air resistance
D. Gravity
Answer:
C . Air resistance
Explanation:
Answer:
Gravity (D)
Explantion:
The more mass the more gravitational force
the more distance the less gravitational force
what is the effect of heat and light on chemical reaction
Which is the most soluble substance listed
Heats makes particles vibrate _________ (btw the options are in the pic)
Answer:ok so When heat is added to a substance, the molecules and atoms vibrate faster. As atoms vibrate faster, the space between atoms increases. The motion and spacing of the particles determines the state of matter of the substance. The end result of increased molecular motion is that the object expands and takes up more space.
hope this helps have a nice day❤️
Explanation:
A student is given a sample of matter and asked to determine whether it is an element, compound, or mixture. The student discovers that she cannot separate
the components of the sample by physical means. However, she is able to separate the sample by chemical means into three different pure substances. The
sample must be______.
A. an element
B. a compound
C. a mixture
D. a solution
Answer is B
A mixture means two compounds mixed together but not atomically. For example, sand and water solution. A water with sand mixed inside is a mixture because the sand can be separated by physical means.
Water is H2O. This means it is a compound, because hydrogen and oxygen is bonded together atomically. Hydrogen however is an element, because you can't seperate it anymore (You could seperate it in the sense of protons and neutrons, but the definition of element is something you can see on the periodic table)
Compound means more than one element bonded together.
The sample must be a compound because it couldn't be seperated by physical means but can be seperated by chemical means into three pure substances (synonym of element)
It takes 38.6 kJ of energy to vaporize 1.00 mol of ethanol (MW: 46.07 g/mol). What will be ΔSsys for the vaporization of 8.00 g of ethanol at 79.6 °C
Answer:
[tex]\Delta S_{sys}=0.020kJ=20J[/tex]
Explanation:
Hello!
In this case, given the required energy to vaporize 1.00 mol of ethanol as the enthalpy of vaporization:
[tex]\Delta H_{vap}=\frac{38.6kJ}{1.00mol}=38.6kJ/mol[/tex]
We can compute the entropy of the system for the vaporization of 8.00 g of ethanol, by first computing the moles:
[tex]n_{et}=8.00g*\frac{1mol}{46.07g} =0.174mol[/tex]
And then setting up the following expression:
[tex]\Delta S_{sys}=\frac{n_{et}*\Delta H_{vap}}{T}[/tex]
Whereas the temperature is in kelvins; thus, we obtain:
[tex]\Delta S_{sys}=\frac{0.174mol*38.6\frac{kJ}{mol} }{79.6+273.15K}\\\\\Delta S_{sys}=0.020kJ=20J[/tex]
Best regards!
The entropy of the system ([tex]\Delta S_{sys}[/tex]) for the vaporization of 8.00 grams of ethanol at 79.6 °C is 0.0190 kilojoules.
Given the following data:
Quantity of energy = 38.6 kJNumber of moles of ethanol = 1 moleMolar mass of ethanol = 46.07 g/molMass of ethanol = 8 gramsTemperature = 79.6 °CConversion:
Temperature = [tex]79.6 + 273 = 352.6 \;K[/tex]
To find the entropy of the system ([tex]\Delta S_{sys}[/tex]) for the vaporization of 8.00 grams of ethanol at 79.6 °C:
First of all, we would determine the heat of vaporization.
[tex]Heat\; of \;vaporization = \frac{Energy}{moles} \\\\Heat\; of \;vaporization = \frac{38.6}{1}[/tex]
Heat of vaporization = 38.6 kJ/mol.
Next, we would determine the number of moles in 8.00 grams of ethanol:
[tex]Number\;of\;moles = \frac{mass}{molar\;mass}\\\\Number\;of\;moles = \frac{8}{46.07}\\\\Number\;of\;moles = 0.1737 \;moles[/tex]
Mathematically, the entropy of a system ([tex]\Delta S_{sys}[/tex]) is given by the formula:
[tex]\Delta S_{sys} = \frac{n\Delta H }{T}[/tex]
Where:
n is the number of moles.T is the temperature.[tex]\Delta H[/tex] is the heat of vaporization.Substituting the given parameters into the formula, we have;
[tex]\Delta S_{sys} = \frac{0.1737 \times 38.6 }{352.6}\\\\\Delta S_{sys} = \frac{6.7048 }{352.6}\\\\\Delta S_{sys} = 0.0190 \;kJ[/tex]
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suppose you start out with only reactants in a rigid container. if the initial concentration of SO2Cl2(g) is 0.543 M, and 43.6% of this initial concentration remains when the system has reached equilibrium, what are the equilibrium concentrations of each gas in the system
Answer:
Explanation:
From the information given:
The Chemical equation is:
[tex]SO_2Cl_{2(g)} \iff SO_{2(g)} + Cl_{2(g)}\\[/tex]
since 43.6% of the initial concentration remains at equilibrium
Then; the amount of [tex]SO_2Cl_2[/tex] that is being reacted is:
= 0.543 × (100 -43.6)%
= 0.306 M
The ICE table can be computed as follows:
[tex]SO_2Cl_2[/tex] ⇔ [tex]SO_{2(g)[/tex] + [tex]Cl_{2(g)[/tex]
I 0.543 0 0
C 0.306 +0.306 0.306
E 0.237 0.306 0.306
[tex]K_c = \dfrac{[SO_2] [Cl_{2}]}{[SO_2Cl_2]}[/tex]
[tex]K_c = \dfrac{0.306 \times 0.306}{0.237}[/tex]
[tex]K_c = 0.995[/tex]
Thus; the concentration at equilibrium for the species are:
[tex]SO_2Cl_2[/tex] = 0.237 M
[tex]SO_{(2g)[/tex] = 0.306 M
[tex]Cl_{2(g)[/tex] = 0.306 M
MEDICAL FORENSICS
please help me i only get one chance to do this please
Answer:
i think the answer is b temperature
Answer:
no
Explanation:
MQ: A disease affecting which of the following might results in a problem with the production of blood cells ?Plsss help!!
Answer:
B bone marrow
Explanation:
I hope it will help
Suppose that X represents an arbitrary cation and that Y represents an anionic species. Using the charges indicated in the superscript of X and Y, fill in the remaining blanks below by writing the appropriate subscript for each X and Y to balance the net charge on the ionic XaYb compound formed (where a and b represent positive, whole numbers of X and Y, respectively).
Y- Y2- Y3-
X+
X2+ XY2
X3+
Answer:
See explanation.
Explanation:
Hello!
In this case, when having the cationic and anionic species with the specified charges, in order to abide by the net charge rule, we need to exchange the charges in the form of subscripts and without the sign, just as shown below:[tex]X^{m+}Y^{n-}\rightarrow X_nY_m[/tex]
Thus, for all the given combinations, we obtain:
- Y⁻
[tex]X^+Y^-\rightarrow XY\\\\X^{2+}Y^-\rightarrow XY_2\\\\X^{3+}Y^-\rightarrow XY_3[/tex]
- Y²⁻
[tex]X^+Y^{2-}\rightarrow X_2Y\\\\X^{2+}Y^{2-}\rightarrow X_2Y_2\rightarrow XY\\\\X^{3+}Y^{2-}\rightarrow X_2Y_3[/tex]
- Y³⁻
[tex]X^+Y^{3-}\rightarrow X_3Y\\\\X^{2+}Y^{3-}\rightarrow X_3Y_2 \\\\X^{3+}Y^{3-}\rightarrow X_3Y_3\rightarrow XY[/tex]
Best regards!
How many grams of water are formed if 3.5 moles of ammonia are used?
Ammonia chemical formula : NH3
Ammonia molar mass : 14 + (1×3) = 17
Mass = Mol × mm
= 3.5mol × 17 = 59.5g
See pic for formula
nvm i think your question is incomplete. pls report my answer i thought u are asking the mass of ammonia
What happens if excess carbon dioxide is not removed from the atmosphere?
A) a decrease in the amount of fossil fuels availabe
B) it may lead to global warming
C) more dead plants and animals not decomposing before getting buried
D) increase in the amount of fossils fuels available
please help fast I need to bring my grade up I'll give 30 points.
Answer:
Carbon dioxide becomes a poisonous gas when there is too much of it in the air you breathe. Besides the effects it can have on the planet and the atmosphere, carbon dioxide poisoning can lead to central nervous system damage and respiratory deterioration in humans and other breathing creatures.
Answer:
Carbon dioxide becomes a poisonous gas when there is too much of it in the air you breathe. Besides the effects it can have on the planet and the atmosphere, carbon dioxide poisoning can lead to central nervous system damage and respiratory deterioration in humans and other breathing creatures.
Explanation:
Hope This Helps! [ :
A closed, nonreactive system contains species Aand Bin vapor/liquid equilibrium. Species Ais a very light gas, essentially insoluble in the liquid phase. The vapor phase contains both species Aand B. Some additional moles of species Bare added to the system, which is then restored to its initial T and P. As a result of the process, does the total number of moles of liquidincrease, decrease, or remain unchanged?
Answer:
Remain unchanged.
Explanation:
The total number of moles of liquid remain unchanged as the some moles of species B are added to the system because specie B that is added in the liquid phase is again restored after addition. If the specie B did not restored after addition to the liquid phase so the total number of moles increases in the liquid phase so that's why we can say that the liquid phase remain unchanged.
20 POINTS! NEED HELP!!!
When naming covalent bonds, do all of the following except?
1. use prefixes
2. write the left-most element first
3. add -ide to the end of the 2nd element
4. write the metal first
Answer:
number 2
Explanation:
even though i have never done this i still got it right
Because metals do not form covalent bonds, when naming covalent bonds, all the given rules apply except write the metal first; option 4.
What are covalent bonds?Covalent bonds are bonds formed by the sharing of valence electrons between the atoms involved in the bonding.
In naming covalent bonds, the following rules are applied:
Name the non-metal furthest to the left on the periodic table by its elemental name.Name the other non-metal by its elemental name and an -ide ending.Use the prefixes mono-, di-, tri-, tetra etc. to indicate the number of that element in the molecule.If the first prefix is mono, it is not written add -ide to the end of the second elementFor example, CO₂, is carbon dioxide.
Therefore, when naming covalent bonds, all the given rules apply except write the metal first because metals do not form covalent bonds.
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The vapor pressure of liquid octane, C8H18, is 40.0 mm Hg at 318 K. A sample of C8H18 is placed in a closed, evacuated container of constant volume at a temperature of 448 K. It is found that all of the C8H18 is in the vapor phase and that the pressure is 71.0 mm Hg. If the temperature in the container is reduced to 318 K, which of the following statements are correct?
a. The pressure in the container will be 42.8 mm Hg.
b. Liquid octane will be present.
c. Only octane vapor will be present.
d. Some of the vapor initially present will condense.
e. No condensation will occur.
Answer:
a, d
Explanation:
a. The pressure in the container will be 42.8 mm Hg.
d. Some of the vapor initially present will condense.
what mass, in grams, of CO2 and H20 N
is formed from 2.55 mol of propane?
Answer: The mass of [tex]CO_2[/tex] and [tex]H_2O[/tex] produced are 336.6 g and 183.6 g respectively.
Explanation:
The combustion reaction between propane and oxygen leads to formation of carbon dioxide and water.
Law of Conservation of mass states that the mass will remain constant for a balanced equation. This is carried out when the total number of atoms on reactant side is same as the total number of atoms on the product side. Thus the equation must be balanced.
[tex]C_3H_8+5O_2\rightarrow 3CO_2+4H_2O[/tex]
a) 1 mol of propane produces = 3 moles of [tex]CO_2[/tex]
Thus 2.55 mol of propane produces = [tex]\frac{3}{1}\times 2.55=7.65 moles of [tex]CO_2[/tex]
mass of [tex]CO_2=moles\times {\text {molar mass}}=7.65mol\times 44g/mol=336.6g[/tex]
b) 1 mol of propane produces = 4 moles of [tex]H_2O[/tex]
Thus 2.55 mol of propane produces = [tex]\frac{4}{1}\times 2.55=10.2 moles of [tex]H_2O[/tex]
mass of [tex]H_2O=moles\times {\text {molar mass}}=10.2mol\times 18g/mol=183.6g[/tex]
The mass of [tex]CO_2[/tex] and [tex]H_2O[/tex] produced are 336.6 g and 183.6 g respectively.
In the periodic table what is the 65th element? (pls help me)
Answer:
Terbium
Explanation:
All elements are put in squares on the periodic table. They represent the number of protons in the nucleus. They are the largest number in the square. The elements go up in order. Number 65 is in the row following Calcium. It is about in the middle of that row.What is the percent composition of dinotrogen pentoxide? With work shown please
Answer:
%N = 25.94%
%O = 74.06%
Explanation:
Step 1: Calculate the mass of nitrogen in 1 mole of N₂O₅
We will multiply the molar mass of N by the number of N atoms in the formula of N₂O₅.
m(N): 2 × 14.01 g = 28.02 g
Step 2: Calculate the mass of oxygen in 1 mole of N₂O₅
We will multiply the molar mass of O by the number of O atoms in the formula of N₂O₅.
m(O): 5 × 16.00 g = 80.00 g
Step 3: Calculate the mass of 1 mole of N₂O₅
We will sum the masses of N and O.
m(N₂O₅) = m(N) + m(O) = 28.02 g + 80.00 g = 108.02 g
Step 4: Calculate the percent composition of N₂O₅
We will use the following expression.
%Element = m(Element)/m(Compound) × 100%
%N = m(N)/m(N₂O₅) × 100% = 28.02 g/108.02 g × 100% = 25.94%
%O = m(O)/m(N₂O₅) × 100% = 80.00 g/108.02 g × 100% = 74.06%
The volume and number of moles of a gas are held constant. Which of the following is true for the pressure of the gas?
It is inversely proportional to the temperature of the gas.
It is directly proportional to the temperature of the gas.
It is inversely proportional to the mass of the gas.
It is equal to the mass of the gas.
Answer:
it is directly proportional to the temperature of the gas
Explanation:
Determine the number of molecules in 0.0500 mole of boron tribromide
(show work)
Answer:
There are 0.5 moles
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number of particles.
To calculate the moles, we use the equation:
Thus there are 0.5 moles
Explanation:
A sample of 523.1 mg of impure KBr is treated with an excess of AgNO3 and 814.5 mg of AgBr is obtained. What is the purity of KBr?
Answer:
98.68%
Explanation:
Step 1: Write the balanced equation
KBr + AgNO₃ ⇒ AgBr + KNO₃
Step 2: Calculate the moles corresponding to 814.5 mg (0.8145 g) of AgBr
The molar mass of AgBr is 187.77 g/mol.
0.8145 g × 1 mol/187.77 g = 4.338 × 10⁻³ mol
Step 3: Calculate the moles of KBr needed to produce 4.338 × 10⁻³ moles of AgBr
The molar ratio of KBr to AgBr is 1:1. The moles of KBr needed are 1/1 × 4.338 × 10⁻³ mol = 4.338 × 10⁻³ mol.
Step 4: Calculate the pure mass corresponding to 4.338 × 10⁻³ moles of KBr
The molar mass of KBr is 119.00 g/mol.
4.338 × 10⁻³ mol × 119.00 g/mol = 0.5162 g
Step 5: Calculate the purity of KBr
0.5162 g of KBr are in a 0.5231 g-sample. The purity of KBr is:
P = 0.5162 g/0.5231 g × 100% = 98.68%
The 2013 Rolls Royce Ghost Alpine has a top speed of 155 miles per hour. Calculate the speed in centimeters per second.
AutoChina Shanghai 2013 also plays host to the world debut of the latest Bespoke Collection from the world’s pinnacle super-luxury marque.
The Alpine Trial Centenary Collection celebrates an extraordinary moment in Rolls-Royce and automotive history. A century ago this June, four Rolls-Royce Silver Ghosts embarked on the Austrian Alpine Trials, the most arduous test of automotive endurance of the time.
In performing without fault over 1820 gruelling miles of near impassable mountain terrain, the Rolls-Royce works team and privateer entrant James Radley helped cement the marque’s reputation for peerless reliability and mechanical excellence, a reputation the company proudly retains today. In doing so establishing the legend of Rolls-Royce as maker of the ‘Best Car in the World’.
This limited edition of Rolls-Royce Ghosts feature exquisitely crafted design cues that pay tribute to these extraordinary motor cars. The exterior paint hue, for example takes close inspiration from Radley’s Silver Ghost, a car that stands side-by-side with the 2013 model in Shanghai.
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