Answer:
80.8%
Explanation:
Let's consider the following balanced equation.
4 Al(s) + 3 O₂(g) → 2 Al₂O₃(s)
The mass obtained of Al₂O₃ (experimental yield) is 84.0 g. The theoretical yield of Al₂O₃ is 104 g. We can calculate the percent yield of Al₂O₃ using the following expression.
%yield = (experimental yield / theoretical yield) × 100%
%yield = (84.0 g / 104 g) × 100% = 80.8%
Answer:
Percent Yield = 80.8%
Explanation:
We can find the percent yield of a reaction using the equation:
Percent yield = Actual yield (g) / Theoretical Yield (g) * 100
Where Actual yield is the amount of product produced (84.0g)
And theoretical yield is the mass produced assuming a 100% of product (104.0g)
Replacing the computed values:
Percent yield = 84.0g / 104.0g * 100
Percent Yield = 80.8%
According to the Vaporization Heat table, the heat needed for 1 mol of H2O to evaporate at 100°C is 40.7KJ and 44.0KJ/mol is needed to evaporate H2O at 25°C. Thus 44.0-40.7=3.7KJ is the energy needed to heat H2O to 100°C from 25°C.
However, according to the heat capacity of H2O, 3.7KJ will only warm the water by ~+43°C, which is not enough to reach 100°C starting from 25°C!
Am I missing something?!
Suppose you have a material in it's liquid phase. As you give energy to that liquid, the temperature of the liquid will increase gradually, and the relation between the increase of temperature and the given energy is the specific heat.
Now, there is a point, a critical point, where the temperature stops to increase, which means that we are near a change of phase. So from this point on, the energy is not used to increase the kinetic energy of the particles (which would increase the temperature), the energy is used to break the bonds and allow a change of phase, for example, from liquid to gas.
So, we know that if you have a mol of water at 100°C, then you need to add 40.7 kJ of energy to change the phase of the water from liquid to gas phase.
This means that if you have a mol of water and you give that exact energy, the temperature will not change, instead, you now will have a mol of water at the temperature of 100°C.
Similarly with the case at 25°C (which happens for a particular pressure only)
So the heat of vaporization can not really be related to increases in temperature as you thought.
For changes in temperature, you need to use the specific heat.
We know that for water it is:
c = 4.184 J/g*°C = 76.15 J/mol*°C
So, if you want to increase the temperature from 25° to 100°
This means an increase of 75°C of one mol of water.
We just need to multiply the above number by:
1mol*(75°C)
Energy needed = (76.15 J/mol*°C)*1mol*(75°C) = 5,711.25 J
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Which type of organic compound is shown below?
A. Carboxylic acid
B. Ester
C. Amine
D. Alcohol
Answer:
I think its A maybe am not sure
When cyclopentane undergo free-radical substitution with bromine (Br2 /Heat) the product:
a. Bromo cyclopentene
b. Bromo cyclopentane + HBr
c. Bromo cyclopentene + HBr
Explanation:
b. Bromo cyclopentane + HBr
A buffer is a solution that: Select one: a. Results from mixing a strong acid and a strong base. b. When added to another solution, decreases the pH. c. When added to another solution, increases the pH. d. Prevents a drastic change in pH when an acid or base enters a solution.
Answer:
d. Prevents a drastic change in pH when an acid or base enters a solution.
Explanation:
The purpose of a buffer is to resist pH change and keep the solution relatively stable.
Three important nutritional additions to training for a long distance race are
O Protein
O Water
O Increase calories
O All of the answer choices
write anode and cathode in Zn-Ag galvanic cell
Explanation:
Zinc is the anode (solid zinc is oxidised). Silver is the cathode (silver ions are reduced).
By convention in standard cell notation, the anode is written on the left and the cathode is written on the right. So, in this cell: Zinc is the anode (solid zinc is oxidised). Silver is the cathode (silver ions are reduced).
Is Water and kerosine a mixture
Answer:
No.Kerosene oil and water do not mix with each other and form two separate layers.
Answer:
No
Explanation:
They cannot be mixed together they will form upper and lower layer
Consider the reaction: NaNO3(s) + H2SO4(l) NaHSO4(s) + HNO3(g) ΔH° = 21.2 kJ
How much heat must absorbed by the reaction system to convert 100g of NaNO3 into NaHSO4(s)?
Please anyone help me out
Data obtained from the question
NaNO₃ + H₂SO₄ —> NaHSO₄(s) + HNO₃ ΔH° = 21.2 KJ
Heat absorbed by converting 100 g of NaNO₃ =? Step 2Determination of the mass of NaNO₃ that was converted from the balanced equation.
Molar mass of NaNO₃ = 23 + 14 + (16×3)
= 23 + 14 + 48
= 85 g/mol
Mass of NaNO₃ from the balanced equation = 1 × 85 = 85 g
Thus, 85 g of NaNO₃ were converted from the balanced equation.
Step 3Determination of the heat absorbed by converting 100 g of NaNO₃.
From the balanced equation above,
When 85 g of NaNO₃ were converted, 21.2 KJ were absorbed by the system.
Thus, the conversion of 100 g of NaNO₃ will cause the system to absorb = [tex]\frac{100 * 21.2}{85} =[/tex] 24.9 KJ of heat energy.
Therefore, the system will absorb 24.9 KJ of heat energy.
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what is the net charge of an ion that as 14 protons 16 electrons and 12 neutrons
Answer:
[tex]\boxed {\boxed {\sf -2}}[/tex]
Explanation:
We are asked to find the net charge of an ion.
The ion has 14 protons, 16 electrons, and 12 neutrons. Recall the charges of each subatomic particle.
Proton: +1 Electron: -1 Neutron: 0Neutrons are neutral and have no charge, so we can ignore them while finding the net charge. There are 14 protons and 16 electrons.
14 protons and 14 electrons have a net charge of 0 because the charges balance each other out. However, we have 16 electrons, which is 2 more than 14. Each electron has a charge of -1, so the 2 electrons add a charge of -2.
The net charge of the ion is -2.
Complete the following nuclear equations. I recommend filling in the atomic number below each symbol. Instead of using superscripts in our answers, put each answer in the corresponding box. A). 54Fe 4He --> 2 1n _____
Answer:
gamma ray
Explanation:
What is the molarity of a solution made by mixing 75.0 mL of 3.00 M NH₄OH with enough water to give 250. mL of solution?
Please explain and show work.
We know
[tex]\boxed{\Large{\sf M_1V_1=M_2V_2}}[/tex]
[tex]\\ \Large\sf\longmapsto M_2=\dfrac{M_1V_1}{V_2}[/tex]
[tex]\\ \Large\sf\longmapsto M_2=\dfrac{3(75)}{250}[/tex]
[tex]\\ \Large\sf\longmapsto M_2=\dfrac{225}{250}[/tex]
[tex]\\ \Large\sf\longmapsto M_2=0.9M[/tex]
Answer:
Mass 1=3M
Mass 2=?
Volume1=75mL
Volume2=250mL
By using molarity formula:
mass1*volume 1=mass2*volume 2
3M*75=mass2*250
mass2=225/250
mass2:0.9M
the molarity of a solution is 0.9M.J00
Sugar
(C2H2011)
260
KNO
220
180
Solubility (g solute per 100 g H,0)
140
NaNO,
NaBr
100
KBr
60
КСІ
Naci
20
0
0
20
Ce (50)
40 60
Temperature (°C)
80
100
Which compound would make a saturated solution if 98 grams were
dissolved in 100 grams of solution at 80 degrees Celsius?
O KBr
O Sugar
OKCI
O NaCl
alish
What happens as energy from sun warms the earth unevenly?
Answer:
Solar heating of the Earth's surface is uneven because land heats faster than water, and this causes air to warm, expand and rise over land while it cools and sinks over the cooler water surfaces.This differential heating is passed on to the air above by conduction which causes air expansion and changes in pressure.
A new member of your team is visually impaired. He's having a hard time reading his computer screen. How can you show that you value diversity? a) Suggest the organization may not be a great fit. O b) Tell him to apply for a different job within the organization that does not b) require computer usage. 12 Od Tell him that he might want to schedule an eye exam. c) d) Provide access to technology that can magnify or read what is on the computer screen.
Answer:
C
Explanation:
If he can't read his computer screen. Means his eyes have problem
A new member of your team is visually impaired. He's having a hard time reading his computer screen. value diversity require computer usage. 12 Tell him that he might want to schedule an eye exam. Therefore, option C is correct.
What is value diversity ?Institutions and community members who value diversity do so in order to recognize the advantages of both their differences and commonalities. They make a deliberate effort to forge enduring connections between individuals and organizations with a broad membership.
When people's unique qualities, abilities, interests, and viewpoints are recognized and supported, they develop a stronger sense of self and health and achieve better results in their academic and professional endeavors.
Although diversity and inclusion are related ideas, they are not the same thing. Diversity has to do with representation or how something is put together. The degree to which the contributions, presence, and viewpoints of other groups of individuals are appreciated and incorporated into a setting is referred to as inclusion.
Thus, option C is correct.
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The condensation of chromosomes is inducted in?
Answer:
Chromosome condensation, the landmark event at the onset of prophase, often begins in isolated patches of chromatin at the nuclear periphery. Later, chromosome condense into two threads termed sister chromatids that are closely paired along their entire lengths.
Explanation:
hope dis help & may I have brainly plz
Rubric #2
Forensic Science
1. Define Nucleus.
2. Define Cytoplasm.
3. Define Cell Membrane.
4. Define DNA.
5. Define Plant.
6. Define Chlorophyll.
7. Define Photosynthesis.
8. How do Plant cells and Animal cells differ?
9. Define Cell Wall.
10. Define Vacuole.
11. Why do cells differentiate in multicellular organisms?
12. Define Multicellular.
13. Complete the Eukaryotic cells and Cell Differentiation assessment.
https://clever.discoveryeducation.com/learn/techbook/units/95c20a43-6d3d-40d3-
848d-89929101140d/concepts/co0fef01-33e7-4116-8819.
143e289e15ba/tabs/6e1551ab-57b8-42d4-8e5b-25549791c760/pages/de4182af-aa 60-
454f-ae5e-28df6f4eb3ac
Explanation:
1. Nucleus is a memberane bound organelle that contains cell,s chromosomes.
what volume will it occupied 40 degrees celsius a gas sample was collected when a temperature is 27 degrees celsius and the volume of 1 L
Using Charles law
[tex]\boxed{\sf \dfrac{V_1}{T_1}=\dfrac{V_2}{T_2}}[/tex]
[tex]\\ \sf\longmapsto V_1T_2=V_2T_1[/tex]
[tex]\\ \sf\longmapsto 1(40)=27V_2[/tex]
[tex]\\ \sf\longmapsto V_2=\dfrac{40}{27}[/tex]
[tex]\\ \sf\longmapsto V_2=1.48\ell[/tex]
how is the molecule of substance formed
Answer:
When atoms approach one another closely, the electron clouds interact with each other and with the nuclei. If this interaction is such that the total energy of the system is lowered, then the atoms bond together to form a molecule.
Explanation:
What is the maximum most that can be extracted from 76 g og Cr2O3.
A) 36 g
B) 52 g
C) 104 g
D) 152 g
Answer:
D) 152 g
Explanation:
a mass of 1 mol Cr2O3 = 2 × 52 + 3 × 16 = 152 g number of moles of Cr2O3.
Calculate the volume of a 89.51 g sample of carbon dioxide at 281.8 K and 843.9 torr. Round your answer
to the nearest L. Do not include units.
Answer:
1,000.000
Explanation:
When (R)-2-chloro-3-methylbutane is treated with potassium tert-butoxide, a monosubstituted alkene is obtained. When this alkene is treated with HBr, a mixture of products is obtained. Identify all of the expected products.
Answer:
See explanation and image attached
Explanation:
The reaction of (R)-2-chloro-3-methylbutane with potassium tert-butoxide yields a monosubstituted alkene .
Since the base is bulky, the Hoffman product predominates because attack occurs at the less hindered carbon atom to yield the major product as shown.
The alkene reacts with HBr at the secondary carbon atom to yield a carbocation intermediate which is flat and planar. Attack on either face of the carbocation yields a racemic mixture of the (2R) and (2S) products.
Rearrangement of the carbocation to yield a tertiary carbocation gives the 2-bromo-2-methyl butane product as shown in the image attached.
The mole fraction of NaCl in an
aqueous solution is 0.132. How
many moles of NaCl are present in
1 mole of this solution?
Molar Mass
NaCl: 58.44 g/mol
H2O: 18.016 g/mol
Answer:
Moles of water are 0.868
Explanation:
A reaction vessel for synthesizing ammonia by reacting nitrogen and hydrogen is charged with 6.54 kg of H2 and excess N2. A total of 30.4 kg of NH3 are produced. What is the percent yield of the reaction
Explanation:
The given data is:
The mass of hydrogen is 6.54 kg.
The actual yield is 30.4 kg.
The balanced chemical equation of the reaction is:
[tex]N_2(g)+3H_2(g)<=>2NH_3(g)[/tex]
At first the theoretical yield should be calculated by using the balanced chemical equation:
3 mol. of hydrogen forms ---- 2 mol. of ammonia.
The molar mass of hydrogen is 2.0 g/mol.
The molar mass of ammonia is 17.0 g/mol.
Hence, the above statement can be rewritten as:
6g of hydrogen forms --- 34g of ammonia.
Then,
6.54g of hydrogen forms :
[tex]6.54 kg x 34 g / 6 g\\=37.1 kg[/tex]
% yield = (actual yield /theoretical yield )x 100
=(30.4 kg /37.1 kg )x100
=81.9
Hence, % yield is 81.9.
A chemist is preparing to carry out a reaction that requires 5.75 moles of hydrogen gas. The chemist pumps the hydrogen into a 10.5 L rigid steel container at 20.0 °C. To what pressure, in kPa, must the hydrogen be compressed? (Show all work for full credit and circle your final answer) *
Answer:
The hydrogen must be compressed to 1333.13302 kPa.
Explanation:
An ideal gas is characterized by three state variables: absolute pressure (P), volume (V), and absolute temperature (T). The relationship between them constitutes the ideal gas law, an equation that relates the three variables if the amount of substance, number of moles n, remains constant and where R is the molar constant of the gases:
P * V = n * R * T
In this case:
P= ?V= 10.5 Ln= 5.75 molesR= 0.082 [tex]\frac{atm*L}{mol*K}[/tex]T= 20 C= 293 K (being 0 C= 273 K)Replacing:
P* 10.5 L= 5.75 moles* 0.082 [tex]\frac{atm*L}{mol*K}[/tex] * 293 K
Solving:
[tex]P=\frac{5.75 moles* 0.082 \frac{atm*L}{mol*K} * 293 K}{10.5 L}[/tex]
P= 13.157 atm
If 1 atm is equal to 101.325 kPa, then 13.157 atm is equal to 1333.13302 kPa.
The hydrogen must be compressed to 1333.13302 kPa.
The Lewis dot model of a molecule is shown.
Based on the model, which of the following is true?
Each carbon has three lone pairs of electrons on it.
The octet of carbon atom remains incomplete in the molecule.
The two carbon atoms share a total of six electrons with each other.
The difference between the electronegativity of carbon and hydrogen is greater than 1.7.
Answer:
The two carbon atoms share a total of six electrons with each other.
Explanation:
Looking at the structure of the molecule H-C≡C-H as shown in the question, we will notice that there exists a triple bond between the two carbon atoms.
Each bond between the two carbon atoms represents two electrons shared. Since there are three bonds between the two carbon atoms, then a total of six electrons were shared between the two carbon atoms hence the answer chosen above.
a 82.6 L sample of gas exerts 350.8 mm hg pressure at 134.6 c°. what valine does the gas have at 736.4 mm hg and 42.8 c°
a. 30.5
b 4.13
c. 12.5
d. 134
need help ASAP
Answer:
nfururhrj waltz quiz amora7ersgdsYsdi6 whiz 53
96rduttie
A person has a standing order for 6 doses of acetaminophen in a 24 hour period for fevers
acetaminophen requires what type of reporting?
ut of
Select one:
a. Routine
estion
b. Emergent
C. Certain Time
d. Urgent
4
A change in the type of seizure the person usually experiences that causes them to stop brea
Acetaminophen is used to treat patients with aches and fever. It is safe to give a dose of 4 grams in 24 hours period.
It is an effective medicine which does not require much time to provide relief to the patient.
Usually tylenol is the best medicine which consists of Acetaminophen in appropriate quantity to provide relief from pain and fever.
The reporting for the doses introduced to the patient must be routine since it is not an emergency case.
The correct answer is a. Routine
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milk has a pH of 6.0 and household ammonia has a pH of 12.0. How much more acidic is milk than ammonia
60 I think bcz if there is 1&2 they differ 10 times
The milk has a pH of 6.0 and household ammonia has a pH of 12.0. then milk will be 6 times milk acidic than ammonia.
What is pH?The pH scale, which previously stood for "potential of hydrogen," would be used to describe how acidic or basic an aqueous solution is.
What is an acidic solution?More hydrogen ions are present in an acidic solution than it was in pure water.
It is given then,
[tex](milk)pH_{1} = 6\\(ammonia)pH_{2} = 12[/tex]
The concentration of hydrogen ions can be calculated by using the formula:
[tex][H^{+}] = 10^{-pH}[/tex]
By putting the value of given data in the above equation.
[tex][H^{+}_{milk} ] / H^{+}_{ammonia}= 10^{-6}/10^{-12}\\ = 10^{6} = 6[/tex]
We get that, milk will be 6 times more acidic than ammonia.
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A 10.53 mol sample of krypton gas is maintained in a 0.8006 L container at 299.8 K. What is the pressure in atm calculated using the
van der Waals' equation for Kr gas under these conditions? For Kr, a = 2.318 L'atm/mol and b = 3.978x10²L/mol.
Answer:
-401.06 atm
Explanation:
Applying,
P = (nRT/V-nb)-(an²/V²)............... Equation 1
Where P = Pressure, R = Universal gas constant, V = molar Volume, T = Temperature in Kelvin, a = gas constant a , b = gas constant b, n = numbers of mole
From the question,
Given: T = 299.8 K, V = 0.8006 L, a = 2.318 L.atm/mol, b = 3.978×10²L/mol
Constant: R = 0.0082 atm.dm³/K.mol
Substitute these values into equation 1
P = [(0.0082×299.8×10.53)/(0.8006-(10.53×397.8)]-[(10.53²×2.318/0.8006²)]
P = (25.89/-4188.0334)-(400.995)
P = -0.0618-400.995
P = -401.06 atm
Buffer solutions that maintain certain levels of pH or acidity are widely used in biochemical experiments. One common buffer system uses sodium dihydrogenphosphate and sodium monohydrogenphosphate. What are the formulas of these two compounds
Answer:
Sodium dihydrogenphosphate = NaH₂PO₄
Sodium monohydrogenphosphate = Na₂HPO₄
Explanation:
A buffer solution is a solution is a solution that resists changes to its oH when a little quantity of strong acid or strong base is added to it.
They are solutions of weak acids or weak bases and their salts known as conjugate base or conjugate acids respectively for the weak acids and weak bases.
For example, a solution of the weak acid ethanoic acid and its salt or conjugate base, sodium ethanoate serves as a buffer solution.
In biochemical experiments, where the pH of the reaction medium is kept as constant and as close as possible to that of the internal environment, buffer solutions are widely used. One of the commonly used buffers is the phosphate buffer. The phosphate buffer consists of the acid salts sodium dihydrogenphosphate and sodium monohydrogenphosphate. Sodium dihydrogenphosphate serves as the weak acid while sodium monohydrogenphosphate serves as the conjugate base.
The formulas of these two compounds are given below:
Sodium dihydrogenphosphate = NaH₂PO₄
Sodium monohydrogenphosphate = Na₂HPO₄
