Answer:
B: Barnacles ride on a gray whale's back to obtain food, and the hale is not harmed.
Explanation:
I got it right on Edge.
Calcium carbonate decomposes to form calcium oxide and carbon dioxide, like this:
CaCO3(s)→CaO(s)+CO2(g)
At a certain temperature, a chemist finds that a 9.0L reaction vessel containing a mixture of calcium carbonate, calcium oxide, and carbon dioxide at equilibrium has the following composition:
Compound Amount
CaCO3 25.3 g
CaO 14.9 g
CO2 33.7 g
Calculate the value of the equilibrium constant Kc for this reaction. Round your answer to 2 significant digits.
Answer: The value of the equilibrium constant Kc for this reaction is 0.088
Explanation:
[tex]Molarity=\frac{x}{M\times V_s}[/tex]
where,
x = given mass
M = molar mass
[tex]V_s[/tex] = volume of solution in L
Equilibrium concentration of [tex]CaCO_3[/tex] = [tex]\frac{25.3}{100\times 9.0}=0.028M[/tex]
Equilibrium concentration of [tex]CaO[/tex] = [tex]\frac{14.9}{56\times 9.0}=0.029M[/tex]
Equilibrium concentration of [tex]CO_2[/tex] = [tex]\frac{33.7}{44\times 9.0}=0.085M[/tex]
The given balanced equilibrium reaction is,
[tex]CaCO_3(s)\rightleftharpoons CaO(s)+CO_2(g)[/tex]
The expression for equilibrium constant for this reaction will be,
[tex]K_c=\frac{[CaO]\times [CO_2]}{[CaCO_3]}[/tex]
Now put all the given values in this expression, we get :
[tex]K_c=\frac{0.029\times 0.085}{0.028}=0.088[/tex]
how many atoms are in 4.67 grams of sample of silicon
How many moles of KBr are present in 500 ml of a 0.8 M KBr solution?
1. 1.6
2. .4
3. .625
4. 625
5. .0016
Answer:
2) 0.4 mol
Explanation:
Step 1: Given data
Volume of the solution (V): 500 mLMolar concentration of the solution (M): 0.8 M = 0.8 mol/LStep 2: Convert "V" to L
We will use the conversion factor 1 L = 1000 mL.
500 mL × 1 L/1000 mL = 0.500 L
Step 3: Calculate the moles of KBr (solute)
The molarity is the quotient between the moles of solute (n) and the liters of solution.
M = n/V
n = M × V
n = 0.8 mol/L × 0.500 L = 0.4 mol
What are the details of the chemical structure of methylisothiazolinone (MIT)?
How many moles of ethanol are produced starting with 500.g glucose?
C6H12O6 → 2 C2H5OH + 2 CO2
5.55 mol C₂H₅OH
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
Reading a Periodic TablesMolesStoichiometry
Using Dimensional AnalysisAnalyzing Reactions RxNExplanation:Step 1: Define
[RxN - Balanced] C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂
[Given] 500. g C₆H₁₂O₆ (Glucose)
[Solve] moles C₂H₅OH (Ethanol)
Step 2: Identify Conversions
[RxN] 1 mol C₆H₁₂O₆ → 2 mol C₂H₅OH
[PT] Molar mass of C - 12.01 g/mol
[PT] Molar Mass of H - 1.01 g/mol
[PT] Molar Mass of O - 16.00 g/mol
Molar Mass of C₆H₁₂O₆ - 6(12.01) + 12(1.01) + 6(16.00) = 180.18 g/mol
Step 3: Stoichiometry
[DA] Set up conversion: [tex]\displaystyle 500 \ g \ C_6H_{12}O_6(\frac{1 \ mol \ C_6H_{12}O_6}{180.18 \ g \ C_6H_{12}O_6})(\frac{2 \ mol \ C_2H_5OH}{1 \ mol \ C_6H_{12}O_6})[/tex][DA} Multiply/Divide [Cancel out units]: [tex]\displaystyle 5.55001 \ mol \ C_2H_5OH[/tex]Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
5.55001 mol C₂H₅OH ≈ 5.55 mol C₂H₅OH
You want to decaffeinate your coffee by extracting the caffeine out with dichloromethane (they don't do it that way anymore, but they used to). It's too late to extract the caffeine from the coffee beans, because you've already brewed yourself a 200 mL cup of coffee. Your particular brand of coffee contains 100 mg of caffeine in that 200 mL cup. The partition coefficient of caffeine in dichloromethane/water is 9.0 (it is more soluble in the dichloromethane).
How much caffeine would still be in your 200 mL if you did:_____.
A. One extraction using 200 mL ofdichloromethane
B. Two extractions using 100 mL ofdichloromethan each.
Solution :
Partition coefficient Kd
[tex]$=\frac{\frac{\text{mass of caffeine in } CH_2Cl_2}{\text{volume of } CH_2Cl_2}}{\frac{\text{mass of caffeine in water}}{\text{volume of water}}}$[/tex]
= 9.0
A). 1 x 200 mL extraction :
Let m be the mass of caffeine in the water
Mass of caffeine in [tex]$CH_2Cl_2$[/tex] = 100 - m
[tex]$\frac{\frac{100-m}{200}}{\frac{m}{200}} = 9.0$[/tex]
[tex]$=\frac{100-m}{m} = 9.0$[/tex]
[tex]$= 10 m = 100$[/tex]
m = 10
Mass remaining in coffee = m = 10 mg
B). 2 x 100 mL extraction :
First extraction :
Let [tex]$m_1$[/tex] be the mass of caffeine in the water
Mass of caffeine in [tex]$CH_2Cl_2$[/tex] = [tex]$100-m_1$[/tex]
[tex]$\frac{\frac{100-m_1}{100}}{\frac{m_1}{200}} = 9.0$[/tex]
[tex]$=\frac{100-m_1}{m_1} = 4.5$[/tex]
[tex]$ 5.5 \ m_1 = 100$[/tex]
[tex]$m_1$[/tex] = 18.18
Mass remaining in coffee = [tex]$m_1$[/tex] = 18.18 mg
Second Extraction :
Let [tex]$m_2$[/tex] be the mass of caffeine in the water
Mass of caffeine in [tex]$CH_2Cl_2$[/tex] = [tex]$18.18-m_2$[/tex]
[tex]$\frac{\frac{18.18-m_2}{100}}{\frac{m_2}{200}} = 9.0$[/tex]
[tex]$=\frac{18.18-m_2}{m_2} = 4.5$[/tex]
[tex]$ 5.5 \ m_2 = 18.18$[/tex]
[tex]$m_2$[/tex] = 3.3
Mass remaining in coffee = [tex]$m_2$[/tex] = 3.3 mg
11. This metalloid has 6 valence electrons and 6 electron shells. I 12. This element has the same number of electrons as a Sulfur ion. SH 10:3 3/3 W
Answer:
11. Polonium.
12. Argon.
Explanation:
In Chemistry, electrons can be defined as subatomic particles that are negatively charged and as such has a magnitude of -1.
Valence electrons can be defined as the number of electrons present in the outermost shell of an atom. Valence electrons are used to determine whether an atom or group of elements found in a periodic table can bond with others. Thus, this property is typically used to determine the chemical properties of elements.
11. Polonium: this metalloid has 6 valence electrons and 6 electron shells. It has 84 electrons with 6 shell structure 2, 8, 18, 32, 18, 6.
Therefore, polonium has the following electronic configuration;
Polonium = 1s² 2s² 2p² 3s² 3p6 3d10 4s² 4p6 4d10 5s² 5p6 4f¹⁴ 5d10 6s² 6p⁴
12. Argon: this element has the same number of electrons as a Sulfur ion. It has 18 electrons.
What are the reasons to determine the melting point of a sample in a melting point apparatus? Select one or more:
A. U Assessment of the sample's purity
B. Conversion of the solid sample to liquid
C. Identification of an unknown sample
D. Removal of impurities from the sample
To prepare a sample in a capillary tube for a melting point determination, gently tap the tube into the sample with the Choose... end of the tube down. Continue tapping until the sample Choose.. end of the tube down, tap the sample down slowly or Choose... to move the sample down Then, with the Choose... faster.
To prepare a sample in a capillary tube for a melting point determination, gently tap the tube into the sample with the a) open, b) closed end of the tube down. Continue tapping until the sample a) completely fills the tube b) is a couple millimeters high, c) has a single crystal in the tube. Then, with the a) closed, b) open end of the tube down, tap the sample down slowly or a) heat the tube up, b) drop the tube into a longer tube, c) shake the tube in the air to move the sample down faster.
Solution :
The reasons for the melting point determines :
the assignment of the sample's purityidentification of the unknown samplethe conversion of solid sample to the liquid completelyIn order to prepare the sample in the capillary tube for determining its melting point, we tap the tube gently into the sample with the open end of tube down. We then continue tapping the tube till the sample is couple of millimeters high.
Then the other close end of tube down, we tap the sample down again slowly or then dropping the tube into a longer tube so as to move down the sample faster.
A 50.0-mL volume of 0.15 M HBr is titrated with 0.25 M KOH. Calculate the pH after the addition of 13.0 mL of KOH. Express your answer numerically.
Answer:
pH= 1.17
Explanation:
The neutralization reaction between HBr (acid) and KOH (base) is given by the following equation:
HBr(aq) + KOH(aq) → KBr(aq) + H₂O(l)
According to this equation, 1 mol of HBr reacts with 1 mol of KOH. Then, the moles can be expressed as the product between the molarity of the acid/base solution (M) and the volume in liters (V). So, we calculate the moles of acid and base:
Acid:
M(HBr) = 0.15 M = 0.15 mol/L
V(HBr) = 50.0 mL x 1 L/1000 mL = 0.05 L
moles of HBr = M(HBr) x V(HBr) = 0.15 mol/L x 0.05 L = 7.5 x 10⁻³ moles HBr
Base:
M(KOH) = 0.25 M = 0.25 mol/L
V(HBr) = 13.0 mL x 1 L/1000 mL = 0.013 L
moles of HBr = M(HBr) x V(HBr) = 0.25 mol/L x 0.013 L = 3.25 x 10⁻³ moles KOH
Now, we have: 7.5 x 10⁻³ moles HBr > 3.25 x 10⁻³ moles KOH
HBr is a strong acid and KOH is a strong base, so they are completely dissociated in water: the acid produces H⁺ ions and the base produces OH⁻ ions. So, the difference between the moles of HBr and the moles of KOH is equal to the moles of remaining H⁺ ions after neutralization:
moles of H⁺ = 7.5 x 10⁻³ moles HBr - 3.25 x 10⁻³ moles KOH = 4.25 x 10⁻³ moles H⁺
From the definition of pH:
pH = -log [H⁺]
The concentration of H⁺ ions is calculated from the moles of H⁺ divided into the total volume:
total volume = V(HBr) + V(KOH) = 0.05 L + 0.013 L = 0.063 L
[H⁺] = (moles of H⁺)/(total volume) = 4.25 x 10⁻³ moles/0.063 L = 0.067 M
Finally, we calculate the pH after neutralization:
pH = -log [H⁺] = -log (0.067) = 1.17
how to convert n butylbenzene to benzoic acid
Answer:
When an alkyl benzene is heated with strong oxidizing asgents like acidic or alkline KMnO4
or acidified K2Cr2O7
, etc. gives aromatic carboxyllic acid. The alkyl side chain gets oxidised to −COOH
group irrespective of the size of the chain.
Explanation:
Which of the following is a true statement?
A. Erosion due to wind-blown sand is a process of chemical weathering.
B. due to wind-blown sand is a process of geological weathering.
C. Erosion due to wind-blown sand is a process of biological weathering.
D.Erosion due to wind-blown sand is a process of mechanical weathering.
Answer:
C
Explanation:
Wind is geological therefore it is geological weathering
Thermal energy that encounters greenhouse gases cannot escape the atmosphere? Yes or no
Answer:
Yes
Explanation:
The point of greenhouse gases is that it absorbs and emits radiant energy within the thermal infrared range and causes it to be trapped.
Looking at the map, what ideas do you have about why the trash is "trapped" in this location
Answer:
Due to the circulation of the wind and water the trash will continue to go around in a circle thus causing it to be trapped there.
Count how many jellybeans are in a jar if the jar has a mass of 30 grams, a
jelly bean has a mass of 2 grams, and the whole jar of jellybeans has a
mass of 230 grams.
Answer:
Ball 16 oz Pint Mason Jar outer dimensions are 5.2 height by 3.2 diameter – which could hold approximately 390 jelly beans. Ball 32 oz Quart Mason Jar outer dimensions are 6.9 height by 3.9 diameter – which could hold approximately 804 jelly beans.Oct 5, 2017
Explanation:
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Answer:
100 jellybeans
Explanation:
Mass of Jar with jellybeans=230 grams
Mass of Jar=30 grams
Mass of 1 jellybean=2 grams
Mass of Jellybeans in jar
=Mass of Jar with jellybeans-Mass of Jar
=230 grams - 30 grams
=200 grams
2 grams=1 jellybean
1 gram=1/2 jellybean
200 grams=200*(1/2) jellybeans=100 jellybeans
While performing a neutralization reaction, Jonna added 27.55 mL of 0.144 M H2SO4 to 43.84 mL of 0.316 M KOH. How many moles of OH- are unreacted in the solution after the neutralization is complete?
Answer:
5.916x10⁻³ mol OH⁻
Explanation:
The reaction that takes place is:
H₂SO₄ + 2KOH → K₂SO₄ + 2H₂OFirst we calculate the added moles of each reagent, using the given volumes and concentrations:
H₂SO₄ ⇒ 0.144 M * 27.55 mL = 3.967 mmol H₂SO₄KOH ⇒ 0.316 M * 43.84 mL = 13.85 mmol KOHNow we calculate how many KOH moles reacted with 3.967 mmol H₂SO₄:
3.967 mmol H₂SO₄ * [tex]\frac{2mmolKOH}{1mmolH_2SO_4}[/tex] = 7.934 mmol KOHFinally we calculate how many OH⁻ moles remained after the reaction
13.85 mmol - 7.934 mmol = 5.916 mmol OH⁻5.916 mmol / 1000 = 5.916x10⁻³ mol OH⁻The face-centered cubic unit cell describing the structure of an ionic compound has an edge length of 207 pm. The lattice points of the unit cell are occupied by anions, and the cations are small enough so that the anions are in contact along the diagonal of the face of the unit cell. What is the ionic radius of the anion (in picometers)
Answer:
73.2 pm
Explanation:
"The anions make contact along the diagonal of the face of the unit cell, so the diagonal of the face is equal to 4 ionic anion radii. By letting r represent the ionic radius of the anion, d represent the diagonal of the face of the unit cell, and x represent the edge length, then d=4r and
d^2=x^2+x^2= 2x^2
By substituting 4r for d, the second equation becomes
(4r)^2=(2)x^2
Solving this equation for r shows that
r=(x–√2)/4
Since the edge length x is 207 pm, the ionic radius of the anion is
r= ((207 pm) X [tex]\sqrt{2}[/tex])/4=73.2 pm
Notice that the formulae used to describe atomic radii include constants with exact values. Therefore, these values do not constrain the number of significant figures."
The ionic radius of the anion in the FCC unit cell where anions are in contact along the diagonal of the face of the unit cell is 73.1pm.
What is ionic radius?Ionic radius is the distance between the center of the atom and the outermost part.
As in the question it is given that anions are in contact along the diagonal of the face of the unit cell, so the length of the diagonal is represented as: d = 4r, where
r = ionic radius
Length of edge i.e. a = 207 pm (given)
Two adjacent edges and diagonal of a FCC unit cell makes a right angle triangle, by using pythagoras theorem we can write as:
a² + a² = d²
2a² = (4r)²
2a²/16 = r²
2(207)²/16 = r²
85,698/16 = r²
0r r = 73.18 pm
Hence, 73.18 pm is the ionic radius of the anion.
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Which of the following chemical substances has a triple
covalent bond?
A. carbon dioxide (CO2)
B. oxygen (0)
C. carbon monoxide (CO)
D. water (H,0)
Answer:
C. Carbon monoxide
Explanation:
Chemical substance which has a triple covalent bond is carbon monoxide.
What is a covalent bond?Covalent bond is defined as a type of bond which is formed by the mutual sharing of electrons to form electron pairs between the two atoms.These electron pairs are called as bonding pairs or shared pair of electrons.
Due to the sharing of valence electrons , the atoms are able to achieve a stable electronic configuration . Covalent bonding involves many types of interactions like σ bonding,π bonding ,metal-to-metal bonding ,etc.
Sigma bonds are the strongest covalent bonds while the pi bonds are weaker covalent bonds .Covalent bonds are affected by electronegativities of the atoms present in the molecules.Compounds having covalent bonds have lower melting points as compared to those with ionic bonds.
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PLEASE HELP IMMEDIATE WORTH 10 POINTS
Fill in the blank with the word or phrase that best completes the statement or answers the question. The scientific name for a plant that reproduces with flowers is a(n)
Answer:
the scientific name is Angiosperms
Explanation:
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Draw Lewis structures for the following compounds/ions. Decide if the compound/ion listed can satisfy the octet rule (duet rule for H), if so choose Satisfies Octet Rule from the drop down menu. If the compound/ion cannot satisfy the octet rule for one of the atoms in the formula, choose one of the following three reasons why; Too many valence electrons (more than eight), Too few valence electrons (fewer than eight), or Odd
The question is incomplete, the complete question is;
Draw Lewis structures for the following compounds/ions.
Decide if the compound/ion listed can satisfy the octet rule (duet rule for H), if so choose Satisfies Octet Rule from the drop down menu.
If the compound/ion cannot satisfy the octet rule for one of the atoms in the formula, choose one of the following three reasons why;
Too many valence electrons (more than eight), Too few valence electrons (fewer than eight), or Odd # of valence electrons.
Satisfies Octet Rule Too many valence electrons Too few valence electrons Odd # of valence electrons KrCl2
Satisfies Octet Rule Too many valence electrons Too few valence electrons Odd # of valence electrons PCl3
Satisfies Octet Rule Too many valence electrons Too few valence electrons Odd # of valence electrons BeH2
Satisfies Octet Rule Too many valence electrons Too few valence electrons Odd # of valence electrons NO3-
Satisfies Octet Rule Too many valence electrons Too few valence electrons Odd # of valence electrons SeO22-
Satisfies Octet Rule Too many valence electrons Too few valence electrons Odd # of valence electrons SO2
Answer:
See explanation
Explanation:
Let us consider the number of valence electrons in each of the species. This will let us know whether the specie satisfies the octet rule or not.
KrCl2 has a total of 22 valence electrons. This implies that there are too many valence electrons hence the compound does not satisfy the octet rule.
For PCl3, there are 26 valence electrons. This compound satisfies the octet rule.
For BeH2, there are four valence electrons. This number of valence electrons is too few hence BeH2 does not satisfy the octet rule.
NO3^- has 24 valence electrons and is represented using resonance structures. Its resonance structures show that the specie satisfies the octet rule.
SeO2^2- has 20 valence electrons. This specie satisfies the octet rule.
SO2 has 18 valence electrons and is represented by resonance structures which satisfy the octet rule.
which property is a property of water
Answer: Polarity, Boiling and Freezing Points, Specific Heat Capacity, Density, Surface Tension, Heat of Vaporization and Vapor Pressure, Capillary Action, Solid State (Ice), Liquid State (Liquid Water), Gas State (Steam),
Explanation: Water molecules are polar, so they form hydrogen bonds. This gives water unique properties, such as a relatively high boiling point, high specific heat, cohesion, adhesion, and density.
what is the constant Kc for Cd²+(aq)+4Br-(aq) CdBr4²-(aq)
Answer:
im only in 6th grade TwT
Explanation:
LOL
Click to review the online content. Then answer the question(s) below, using complete sentences. Scroll down to view additional questions.
Online Content: Site 1
How did the gold rush transform Australia? (Site 1)
marking brainliest
Answer:
In 1851 gold-seekers from around the world began pouring into the colonies, changing the course of Australian history. The gold rushes greatly expanded Australia's population, boosted its economy, and led to the emergence of a new national identity.
Explanation:
Answer:
People from all over the world look for gold and in 1851 people started forming colonies to look for it which had a huge impact on the history of Australia. The gold rushes increased Australia's population which improved its economy.
GIVING 21 POINTS AWAY PLEASE HELP ME WITH BOTH QUESTIONS ASAP!!!!
Mario’s teacher asked him to explain the important role of the sun in the water cycle. Which response would be correct?
what is the answer please
Answer:
A.
Explanation:
A decomposition reaction is when one reactant (the substances to the left of the arrow in the reaction) breaks apart into two or more products (the substances to the right of the arrow).
Because KClO3 is breaking down into KCl and O2, it's a decomposition reaction.
Which element best conducts electricity?
argon
copper
nitrogen
oxygen
Answer:
I think it is copper
Explanation:
.........................
Answer:
copper
Explanation:
When the North Pole of one magnet is next to another North Pole of the other manger they will repel. True or false
I need help ASAP plz :)
A factory in your town uses cadmium as part of its manufacturing process. Due to recent economic conditions, cadmium is no longer available, and you must find a replacement. Suggest two elements that might be good replacements. Which of these would be your choice? Explain why.
Answer:
Zn
Explanation:
I have a balloon that can hold 100. liters
of air. If I blow up this balloon with 3.0
moles of oxygen gas at a pressure of 1.0
atmosphere, what is the temperature of
the balloon?
Answer:
T = 4.062V
Explanation:
from PV = nRT => T = PV/RT
P = 1 atm
V = Final Volume
n = 3 moles
R = 0.08206 L·atm/mol·K
T = ?
T = 1 atm · V(Liters)/(3 moles)(0.08206L·atm/mol·K) = 4.062·V(final) Kelvin
The temperature of the balloon is 406 K
We'll begin by listing out what was given from the question. This is shown below:
Volume (V) = 100 L
Mole of oxygen (n) = 3 moles
Pressure (P) = 1 atm
Temperature (T) =?We can obtain the temperature of the balloon by using the ideal gas equation as shown below:
PV = nRTNOTE:P is the pressure.
V is the volume.
n is the number of mole
R is the gas constant (0.0821 atm.L/Kmol)
T is the temperature.
Applying the ideal gas equation, we have:
PV = nRT
1 × 100 = 3 × 0.0821 × T
100 = 0.2463 × T
Divide both side by 0.2463
T = 100 / 0.2463
T = 406 KTherefore, the temperature of the balloon is 406 K
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