Calculate the average atomic mass of an element containing 39.9% of atoms with a mass of 69 amu and 60.1% of atoms with a mass of 71 amu. Show your work for credit and round your answer to one decimal place.
Answer:
70.202 amu
Explanation:
From the question given above, the following data were obtained:
Isotope A:
Abundance (A%) = 39.9%
Mass of A = 69 amu
Isotope B:
Abundance (B%) = 60.1%
Mass of B = 71 amu
Average atomic mass =?
The average atomic mass of the element can be obtained as follow:
Average atomic mass = [(Mass of A × A%)/100] + (Mass of B × B%)/100]
= [(69 × 39.9)/100] + [(71 × 60.1)/100]
= 27.531 + 42.671
= 70.202 amu
Therefore, the average atomic mass of the element is 70.202 amu
The pH of 0.259 M solution of an unknown acid is measured to be 2.353. What is the Ka of the acid?
Answer:
[tex]Ka=7.73x10^{-5}[/tex]
Explanation:
Hello!
In this case, since the pH is measure of the amount of hydrogen ions in solution, first given the pH we can compute the concentration of hydrogen ions via:
[tex]pH=-log([H^+])[/tex]
[tex][H^+]=10^{-pH}=10^{-2.353}=4.436x10^{-3}M[/tex]
Thus, since the ionization of the given acid, leads to the following equilibrium expression as it is a weak one:
[tex]Ka=\frac{[H^+][A^-]}{[HA]}[/tex]
We notice the concentration of hydrogen ions equal the concentration of the acids conjugate base, so we can compute:
[tex]Ka=\frac{4.436x10^{-3}*4.436x10^{-3}}{0.259-4.436x10^{-3}}\\\\Ka=7.73x10^{-5}[/tex]
Best regards!
CAN you pleaaaase solve this? please please please
Answer:
115.2ml of water should be added.
Explanation:
We start with 46.2ml of 1.396M sugar solution;
We want to end up with a 0.56M sugar solution;
Finding the number of moles in the sugar solution to begin with:
moles of sugar in solution initially = 46.2 × 1.396 = 64.4952
Vd = volume of desired solution (i.e. 0.56M solution)
w = volume of water added
Vd = (46.2 + w)
Using the mol = vol' × conc'n equation:
64.4952 = Vd × 0.56
Vd = 64.4952/0.56
Vd = 115.17
46.2 + w = 115.17
w = 115.17 - 46.2
w = 68.97ml
why is a bannana curved?
Answer:
Explanation:
It's because of the sun! Bananas are curved so they can retrieve sunlight.
give him the brainliest
What is the frequency of a photon that has a wavelength of 754 um?
Answer:
Explanation:
What is the frequency of a photon that has a wavelength of 754 um?
if one knows the mass and the molar mass of product D in a chemical reaction, one can determine the mass of product D procued by using the?
Answer:
Number of moles
Explanation:
Using the number of moles in chemical reactions, we can determine the quantity of products and even the reactants that are combining to form them.
The number of moles is derived using the expression below is;
Number of moles = [tex]\frac{mass}{molar mass}[/tex]
Once we establish the number of moles of any of the specie given from the mass and molar mass, we can relate it to any other species.
Question 10 of 10 Which of the following compounds is the most stable? A. Agci B. LICI C. AlCl3 D. CuCl2
Answer:
b
Explanation:
A nuclear equation is balanced when?
A balanced nuclear reaction equation indicates that there is a rearrangement during a nuclear reaction, but of subatomic particles rather than atoms. Nuclear reactions also follow conservation laws, and they are balanced in two ways: The sum of the mass numbers of the reactants equals the sum of the mass numbers of the products.
Please mark brainliest:)
How might the molecules inside an ice pack be different from the liquid inside of an insulated cup?
Answer:
The molecules inside the ice pack are frozen therefore they are stuck in place. The molecules inside an insulated cup aren't frozen but still stuck inside of their container so that they can not fly out.
Explanation:
Perform the following calculation with the
correct number of significant figures.
12.62 +2.3 + 0.34 = ?
Introduction:
Briefly describe the physical behavior you investigated.
What is the exploration about?
What are you trying to discover?
Relate to any previous work.
Use new vocabulary words, if you can.
Answer: im not sure if this is the best answer but i wrote, "This exploration is about how the volume of a gas varies with temperature, and what the effect does to the gas and what effect it has on the results."
Explanation: hope this helps.
This exploration is about how the volume of a gas varies with temperature, and what the effect does to the gas and what effect it has on the results."
Thus, For persons with autism, life can be incredibly stressful at times, and their behaviour may be an indication of their utter exasperation or suffering in reaction to a variety of pressures.
Some people struggle with the idea of time and sequencing, thus this can involve onerous tasks, meeting new people, experiencing unpleasant sensory stimuli, a change in routine, switching activities, or having to wait for anything.
The individual may have realized how effective their actions could be in influencing their environment. A behaviour that was initially a reaction to physical discomfort or frustration may later develop into a strategy for evading a request or getting rid of an uncomfortable circumstance.
Thus, This exploration is about how the volume of a gas varies with temperature, and what the effect does to the gas and what effect it has on the results."
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The question is Incomplete, the complete question is:
Briefly describe the physical behavior?
What is the exploration about?
What are you trying to discover?
Relate to any previous work.
Use new vocabulary words, if you can.
In the exploration, I was a bird trying to eat bugs placed in different backgrounds. Each bug was adifferent color, and the color either matched or stood out against the background. What I wastrying to discover was how creatures adapted to their environment and if blending in with theirenvironment helped them or hindered them. I discovered that yes, blending in with theenvironment helps creatures survive.
what type of element is usually shiny
Answer:
Metal
Explanation:
Answer:
Explanation:metals
Consider the following reaction. MgCl2(aq)+2NaOH(aq)⟶Mg(OH)2(s)+2NaCl(aq) A 187.0 mL solution of 0.103 M MgCl2 reacts with a 33.58 mL solution of 0.839 M NaOH to produce Mg(OH)2 and NaCl. Identify the limiting reactant.
Answer:
NaOH is the limiting reactant and MgCl2 is in excess.
Explanation:
let's calculate the mole of each reactant.
number of moles of MgCl2 = [tex]\frac{187}{1000} L* 0.103 mol / L =0.01926 mol\\[/tex]
number of moles of NaOH = [tex]\frac{33.58 }{1000}L * 0.839 mol/L =0.0282 mol[/tex]
as per the reaction , 1 mol of Magnesium choloride reacts with 2 moles of NaOH
hence 0.01926 needs 0.01926x2= 0.03852 moles of NaOH , but there are only 0.0282 moles of NaOH available .
The limiting reactant for the reaction between 187.0 mL solution of 0.103 M MgCl₂ and 33.58 mL solution of 0.839 M NaOH is NaOH
We'll begin by calculating the number of mole of MgCl₂ and NaOH present in the solution.
For MgCl₂:Volume = 187 mL = 187 / 1000 = 0.187 L
Molarity = 0.103 M
Mole of MgCl₂ =?Mole = Molarity x Volume
Mole of MgCl₂ = 0.103 × 0.187
Mole of MgCl₂ = 0.019 mole For NaOH:Volume = 33.58 mL = 33.58 / 1000 = 0.03358 L
Molarity = 0.839 M
Mole of NaOH =?Mole = Molarity x Volume
Mole of NaOH = 0.839 × 0.03358
Mole of NaOH = 0.028 moleFinally, we shall determine the limiting reactant. This can be obtained as follow:
MgCl₂ + 2NaOH —> Mg(OH)₂ + 2NaCl
From the balanced equation above,
2 moles of NaOH required 1 mole of MgCl₂.
Therefore, 0.028 mole of NaOH will require = [tex]\frac{0.0282}{2}\\[/tex] = 0.014 mole of MgCl₂
From the calculations made above, we can see that only 0.014 mole of MgCl₂ out of 0.019 mole reacted completely with 0.028 mole of NaOH.
Therefore, NaOH is the limiting reactant and MgCl₂ is the excess reactant.
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Two gas jars are connected to each other, but they are separated by a closed valve. One gas jar contains oxygen, and the other is empty. What will happen when the valve is opened? (3 points)
a
Oxygen molecules will remain in their original jar because of the very high density of the oxygen molecules.
b
Oxygen molecules will remain in their original jar because there is enough space in the original jar.
c
Oxygen molecules will spread evenly throughout both jars because of weak intermolecular forces.
d
Oxygen molecules will spread through both jars because of the high molecular weight of oxygen.
Answer:
d) Oxygen molecules will spread through both jars because of the high molecular weight of oxygen.
Explanation:
Oxygen molecules will spread evenly throughout both jars because of weak intermolecular forces.
Intermolecular forces hold the molecules of matter together in a particular state of matter.
Gases have the weakest intermolecular forces between them. As such, the molecules of gases are isolated from each other and they move at very high velocities.
Due to weak intermolecular forces between the molecules of oxygen gas, when the valve between the two jars is opened, oxygen gas spreads evenly throughout the both jars.
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What type of reaction is: 4 Fe + 3 O2 → 2 Fe2O3
A. synthesis
B. double replacement
C. decomposition
D. single replacement
Answer:
A. synthesis
Explanation:
The reaction given is a synthesis reaction in which two substances combines to give a product.
In this reaction:
4Fe + 3O₂ → 2Fe₂O₃
The reaction involves the formation of a single product from two or more reactants.
The formation of a compound from union of the constituent elements also falls into this category of reaction.
At constant pressure for which of the reactions shown below should Delta H be greater than Delta E°?
1.2 SO2(g) + O2(g) - 2 SO3(g)
II. C5H12(9) + 8 O2(g) - 5 CO2(g) + 6 H20(1)
III. H2(g) + Br2(g) → 2 HBr(9),
IV. N204(9) - 2 NO2(g)
Answer: [tex]N_2O_4(g)\rightarrow 2NO_2(g)[/tex] has higher value of [tex]\Delta H[/tex] than [tex]\Delta E[/tex]
Explanation:
The realtion between enthalpy change and internal energy change is:
[tex]\Delta H=\Delta E+\Delta n_gRT[/tex]
where,
= enthalpy of the reaction
= internal energy of the reaction
[tex]\Delta n_g[/tex] = change in the gaseous moles of the reaction = Moles of product - Moles of reactant
R = gas constant
T = temperature
1. [tex]2SO_2(g)+O_2(g)\rightarrow 2SO_3(g)[/tex]
[tex]\Delta n_g[/tex] = 2-3 = -1
2. [tex]C_5H_{12}(g)+8O_2(g)\rightarrow 5CO_2(g)+6H_2O(l)[/tex]
[tex]\Delta n_g[/tex] = 5-9 = -4
3. [tex]H_2(g)+Br_2(g)\rightarrow 2HBr(g)[/tex]
[tex]\Delta n_g[/tex] = 2-2 = 0
4. [tex]N_2O_4(g)\rightarrow 2NO_2(g)[/tex]
[tex]\Delta n_g[/tex] = 2-1 = 1
Thus reaction . [tex]N_2O_4(g)\rightarrow 2NO_2(g)[/tex] has higher value of [tex]\Delta H[/tex] than [tex]\Delta E[/tex]
At constant pressure the given reaction that shows ΔH would be greater than ΔE is;
IV); N₂0₄(g) → 2NO₂(g)
In chemistry, he meaning of ΔH and ΔE are;
- ΔH means the change in enthalpy, which is heat content.
- ΔE means the change in energy of a system.
Now, for a closed system the relationship between ΔH and ΔE is given by;
ΔH = ΔE + PΔV
where PΔV = ΔnRT
Thus; ΔH = ΔE + ΔnRT
where Δn = number of moles of product in the gaseous state - number of moles of reactants.
Thus, if Δn is negative, then ΔE would be greater than ΔH but if Δn is positive, then ΔH would be greater than ΔE
I) 2SO₂(g) + O₂(g) ⇒ 2SO₃(g)
number of moles of product = 2
number of moles of reactants = 2 + 1 = 3
Δn = 2 - 3
Δn = -1 and so ΔE would be greater than ΔH
II) C₅H₁₂(g) + 8O₂(g) ⇒ 5CO₂(g) + 6H₂0(l)
number of moles of product = 5 (6 is not used because water is in liquid and not gas)
number of moles of reactants = 8 + 1 = 9
Δn = 5 - 9
Δn = -4 and so ΔE would be greater than ΔH
III) H₂(g) + Br₂(g) → 2HBr(g)
number of moles of product = 2
number of moles of reactants = 1 + 1 = 2
Δn = 2 - 2
Δn = 0 and so ΔE would be equal to ΔH
IV) N₂0₄(g) → 2NO₂(g)
number of moles of product = 2
number of moles of reactants = 1
Δn = 2 - 1
Δn = +1 and so ΔH would be greater than ΔE
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A 1.59 mol sample of Kr has a volume of 641 mL. How many moles of Kr are in a 4.41 L sample at the same temperature and pressure?
Answer:
The correct answer is 10.939 mol ≅ 10.94 mol
Explanation:
According to Avogadro's gases law, the number of moles of an ideal gas (n) at constant pressure and temperature, is directly proportional to the volume (V).
For the initial gas (1), we have:
n₁= 1.59 mol
V₁= 641 mL= 0.641 L
For the final gas (2), we have:
V₂: 4.41 L
The relation between 1 and 2 is given by:
n₁/V₁ = n₂/V₂
We calculate n₂ as follows:
n₂= (n₁/V₁) x V₂ = (1.59 mol/0.641 L) x 4.41 L = 10.939 mol ≅ 10.94 mol
The number of moles is 10.94 mol.
The calculation is as follows:
As per the Avogadro gases law, the no of moles at the same pressure & temperature should be proportional to the volume.The following formula should be used:
[tex]n_1\div V_1 = n_2\div V_2\\\\n_2= (n_2\div V_1) \times V_2\\\\ = (1.59 mol\div 0.641 L) \times 4.41 L[/tex]
= 10.939 mol
= 10.94 mol
Therefore we can conclude that the number of moles is 10.94 mol.
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What is the percent yield for carbon dioxide if 10.0 grams of carbon
monoxide yielded 12.81 grams of carbon dioxide from the reaction
below?
2 CO + O2 → 2 CO2
The percent yield : 81.5%
Further explanationPercent yield is the compare of the amount of product obtained from a reaction with the amount you calculated
General formula:
Percent yield = (Actual yield / theoretical yield )x 100%
An actual yield is the amount of product actually produced by the reaction. A theoretical yield is the amount of product that you calculate from the reaction equation according to the product and reactant coefficients
Reaction
2CO+O₂⇒2CO₂
mol CO(MW=28,01 g/mol)
[tex]\tt \dfrac{10}{28.01}=0.357[/tex]
mass CO₂ (theoretical)(MW=44,01 g/mol)
[tex]\tt 0.357\times 44.01=15.712~g[/tex]
the percent yield :
[tex]\tt \dfrac{12.81}{15.712}\times 100\%=81.5\%[/tex]
Which additional product balances the reaction H2SO4 + 2NaOH → Na2SO4 + ? 2H2O 2OH H2O2 H3O
Answer:
a) 2H2O
Explanation:
I took the quiz
Answer:
2H20 or A- the other person was right:) give them brainliest.
Explanation:
I just took the test.
What is the formula for Mercury (I) Bisulfate?
Answer:
Work shown below!
Explanation:
[tex]Hg^{+1} HSO_{4} =HgHSO_{4}[/tex]
18 protons
22 neutrons
18 electrons
how do i draw this ? please help ASAP.
Explanation:
You need to remember a few things if you want the answer to this question...
A atom has a circle within a circle so consider that it looks like a double circle..Protons and neutrons go in the center of that double circle..Electrons go on the outer sides of the two circles.Because of the given numbers of protons, neutrons, and electrons we know that the element you need to draw is Argon.Therefore you need to draw a atom that is similar to this:
Hope this helps.
Models can represent systems
and processes.this is a true or false question
Answer:
True
Explanation:
Hope this helps! :)
Answer:
This is True.
Explanation:
Write the complete and balanced combustion reaction for H2+O2—>
Answer:
2H2 + 02 --> 2H20
Explanation:
H2 + 02 --> H2O
H =2x2 = 4 | H = 2 x 2 = 4
|
O =2 | O = 1 x 2 = 2
dm me if u have questions regarding the solution hihi :)
When is a roman numeral most likely needed in the name of an ionic compound?
A. When more than one polyatomic ion appears.
B. When the anion is a polyatomic ion.
C. When more than one cation is used in the formula.
D. When the cation is a transition metal.
Answer:I think it's d but I could be wrong
which of these is the smallest unit?
ds
ks
cs
ms
Answer:
ks
Explanation:
Is it right
A falling book in mid-air has___
A. both potential and kinetic energy
B. only kinetic energy
C. chemical energy
D. only potential energy
The potential and kinetic energy of a falling book is present. Kinetic energy is indeed the force driving motion, manifested in the motion of a particle, an object, or a collection of particles.
The correct answer is A
Where is the lack of kinetic energy located?Kinetic energy is the term for the energy present in an object in motion. Examples of velocity include your movement as you walk down the street and the planet's rotation around the sun. The formula for kinetic energy is as follows: K.E. is equal to half of an object's mass times its square velocity, or m/v2.
How come kinetic energy is so crucial?The capacity of kinetic energy to perform work is perhaps its most significant quality. The force applied to that of an object when it is moving is referred to as work. This intimate relationship between work and energy makes them go together.
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Scientists study and record seismic data and volcanic activity in order to support: Convection in the Lithosphere Theory of Plate Tectonics Sea Floor Spreading Theory of Continental Drift
Answer:
Theory of Plate Tectonics
Explanation:
Scientists especially Geologists study and record seismic data and volcanic activities in order to support the theory of plate tectonics.
The theory of plate tectonics suggests that the earth is broken into slabs called the lithosphere that moves over the fluid asthenosphere below.
The use of seismic data presents scientists with a way of vertically looking deep into the earth. Volcanic activities also presents us with the kind of materials down within the earth. Also, coupled with this data, scientists use GPS sensors to monitor the rate of movement of the earth. When studying plate tectonics, it invariably culminates in the study of sea floor spreading and theory of continental drift.In which of the following elements is the least
amount of energy required to remove the most
loosely bound electron from an atom in the gaseous
state?
A) Sr
B) Ar
C) Al
D C
Answer:
A) Sr
Explanation:
Strontium will require the least amount of energy to remove the most loosely bound electrons from its atom in gaseous state.
This parameter is known as the ionization energy. It is defined as the readiness of an atom to lose an electron.
Metals in group 1 and 2 generally have very low ionization energy due to their large electropositivity The more electropositive a metal is, the lower its ionization energy. This is the reason why strontium will have the least ionization energy."All is strange and vague."
"Are we dead?"
"Or is this Ohio"
-Animaniacs
Oh yeah, brainliest if you can answer this question :3
Answer:
This is Ohio.
Explanation:
(no dude im dead i live in kentucky XP)
Which type of drug commonly marketed to consumers does not require a prescription?
A. antidepressant
B. blood pressure medication
C. pain reliever
Answer:
pain reliever
Explanation: