A cooling curve has two flat lines, or plateaus. The plateau at the higher temperature represents condensation of a gas and the correct option is option C.
What is Cooling curve?
When a solid substance is heated until it is completely melted, and then heated further and allowed to cool slowly, the curve obtained by plotting temperature against time is known as the cooling curve.
The gradient of the cooling curve is related to the heat capacity, the thermal conductivity of the substance, and the external temperature. The more heat is required to change the temperature of the substance, the slower it cools, so the smaller the gradient of the curve. The higher the thermal conductivity, the faster heat is transferred, so the faster the substance cools.
Therefore, A cooling curve has two flat lines, or plateaus. The plateau at the higher temperature represents condensation of a gas and the correct option is option C.
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Part A Indicate whether each statement is true or false. Sort these statements into the proper categories. ResetHelp NaClNaCl dissolves in water but not in benzene because the water-ion interactions are stronger than benzene-ion interactions.NaClNaCl dissolves in water but not in hexane because the enthalpy of mixing NaClNaCl with water is more negative than that of mixing NaClNaCl with hexane.NaClNaCl dissolves in water but not in benzene (C6H6)(C6H6) because there are no hydrogen bonds in benzene. True False
Answer:
Explanation:
NaCl dissolves in water but not in benzene because the water-ion interactions are stronger than benzene-ion interactions.
This statement is true . NaCl is ionic compound . I water is ionises strongly because of strong ion - water interaction . It does not dissolve in benzene because of low ion - benzene interaction .
NaCl dissolves in water but not in hexane because the enthalpy of mixing NaCl with water is more negative than that of mixing NaCl with hexane.
This statement is wrong because enthalpy of mixing NaCl with water is positive and not negative .
NaCl dissolves in water but not in benzene(C6H6) because there are no hydrogen bonds in benzene.
This statement is wrong . NaCl does not make hydrogen bond with water molecule .
NaCl dissolves in water but not in benzene because the water-ion interactions are stronger than benzene-ion interactions.This statement is true .
What is an ion ?The term ion is defined as an ion is an atom or molecule with a net electrical charge. There are two types of ions that are cation and anion.
This statement is true . NaCl is an ionic compound . The water is ionizes strongly because of strong ion - water interaction . It does not dissolve in benzene because of low ion - benzene interaction .
NaCl dissolves in water but not in hexane because the enthalpy of mixing NaCl with water is more negative than that of mixing NaCl with hexane. This statement is wrong because enthalpy of mixing NaCl with water is positive and not negative .
NaCl dissolves in water but not in benzene(C6H6) because there are no hydrogen bonds in benzene. This statement is wrong . Because NaCl does not make hydrogen bond with water molecule .
Thus, NaCl dissolves in water but not in benzene because the water-ion interactions are stronger than benzene-ion interactions.
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What is the solubility of cerium (III) sulfate at 10ºC?
PLEASE HELP 100 POINTS
Write a paragraph (3-4 complete sentences) using at least of the vocabulary words demonstrating how nitrogen is recycled throughout the ecosystem. (using these words)
Nitrogen Nitrates Ammonium
Nitrites Nitrogen Fixation Denitrification
Answer:
Gaseous nitrogen (78% in air) is fixed (by nitrogen fixing bacteria, and during lightning), then absorbed and assimilated by plants in the form of proteins, as well as nucleic acids. ... Nitrogen is returned to soil with excretory materials of animals and dead organisms.
Explanation:
Nitrates (or nitrites) are natural chemicals that are found in the soil, air and water. Nitrates are also used as a food additive to stop the growth of bacteria and to enhance the flavor and color of foodsAmmonium is also a general name for positively charged or protonated substituted amines and quaternary ammonium cations (NR + 4. ), where one or more hydrogen atoms are replaced by organic groups (indicated by R).an obsessive interest in or feeling about someone or something.
"our fixation with diet and fitness"
Denitrification: the loss or removal of nitrogen or nitrogen compounds specifically : reduction of nitrates or nitrites commonly by bacteria (as in soil) that usually results in the escape of nitrogen into the air
1. Imagine that you need to take a medicine that the doctor has prescribed for
you. Explain why scientists who developed that medicine would need to know
whether or not the compound in that medicine is polar. How might a polar
medicine behave differently as it dissolved in the body than a nonpolar medicine
would? Answer in 1 to 2 paragraphs. (10 points) Think about how polar and
nonpolar compounds might behave differently in the watery environment of your
stomach or bloodstream
Answer: Only non-polar medicines can diffuse across the membrane. non-polar drugs are lipid soluble, while polar drugs are water soluble, so polar drugs cant absorb through biological membranes.
2. Methyl dichloroacetate (Cl2CHCO2CH3) decays into methanol (CH3OH) and dichloroacetic acid (Cl2CHCO2H) on reaction with water. Given a rate constant of 2.7 x 10-4/sec and an initial concentration of 1-ppm methyl dichloroacetate in the water, how much methanol will be present in the water after 30 min
Answer:
2.69 * 10^-6 Mol/L
Explanation:
The equation of the reaction is;
Cl2CHCO2CH3 -------------------> Cl2CHCO2H + CH3OH
To convert from ppm concentration to Mol/L, we have
M = ppm/MM * 1000
Where;
M = mol/l
MM= Molar mass
M = 1/142.97 g/mol * 1000 =
M= 6.99 * 10^-6 Mol/L
For first order reaction;
ln[A] = ln[A]o -kt
Given that
[A]o = 6.99 * 10^-6 Mol/L
[A]=??
k= 2.7 x 10-4/sec
t= 30 mins * 60 = 1800 s
ln[A] = ln[6.99 * 10^-6] - (2.7 x 10-4 * 1800)
ln[A] = -11.87 - 0.486
ln[A] = -12.356
[A] = e^(-12.356)
[A] = 4.3 * 10^-6 Mol/L
Concentration of methanol present after 30 mins= 6.99 * 10^-6 - 4.3 * 10^-6 = 2.69 * 10^-6 Mol/L
A solid sample of Zinc Hydroxide is added to 0.350 L of 0.500 M aqueous Hydrogen Bromide. The solution that remains is still acidic. It is then titrated with 0.500 M NaOH solution, and it takes 88.5 mL of the NaOH solution to reach the equivalence point. What mass of Zinc Hydroxide was added to the Hydrogen Bromide solution?
Answer:
6.499 g
Explanation:
One part of the aqueous HBr reacted with Zinc Hydroxide following the reaction:
Zn(OH)₂ + 2HBr → ZnBr₂ + 2H₂OAnd the remaining HBr reacted with NaOH:
NaOH + HBr → NaBr + H₂OFirst we calculate how many HBr moles remained after reacting with Zn(OH)₂. That number equals the number of NaOH moles used in the titration:
0.500 M * 88.5 mL = 44.25 mmol NaOH = mmol HBrNow we calculate how many moles of HBr reacted with Zn(OH)₂:
Originally there were (350 mL * 0.500 M) 175 mmol HBr175 mmol - 44.25 mmol = 130.75 mmol HBrThen we convert those 130.75 mmoles of HBr to the Zn(OH)₂ moles they reacted with:
130.75 mmol HBr * [tex]\frac{1mmolZn(OH)_{2}}{2mmolHBr}[/tex] = 65.375 mmol Zn(OH)₂.Finally we convert Zn(OH)₂ moles to grams:
65.375 mmol Zn(OH)₂ * 99.424 mg/mmol = 6499.8 mg Zn(OH)₂6499.8 mg Zn(OH)₂ / 1000 = 6.499 gSound waves are longitudinal, mechanical, compression waves.
A. True
B. False
Answer:
True
Explanation:
Sound waves traveling through air are indeed longitudinal waves with compressions and rarefactions. As sound passes through air (or any fluid medium), the particles of air do not vibrate in a transverse manner.
Answer:
true
Explanation:
ape x
Helppppp pleaseeee xxxxxx
Answer:
2812.6 g of H₂SO₄
Explanation:
From the question given above, the following data were obtained:
Mole of H₂SO₄ = 28.7 moles
Mass of H₂SO₄ =?
Next, we shall determine the molar mass of H₂SO₄. This can be obtained as follow:
Molar mass of H₂SO₄ = (1×2) + 32 + (16×4)
= 2 + 32 + 64
= 98 g/mol
Finally, we shall determine the mass of H₂SO₄. This can be obtained as follow:
Mole of H₂SO₄ = 28.7 moles
Molar mass of H₂SO₄ =
Mass of H₂SO₄ =?
Mole = mass / Molar mass
28.7 = Mass of H₂SO₄ / 98
Cross multiply
Mass of H₂SO₄ = 28.7 × 98
Mass of H₂SO₄ = 2812.6 g
Thus, 28.7 mole of H₂SO₄ is equivalent to 2812.6 g of H₂SO₄
Geosmin is an aroma compound found in raindrops. It's chemical formula is C12H22O. The molar mass is 182 g/mol. If you perform combustion analysis of 1.77 grams of this compound, how many grams of carbon should be isolated as CO2 during the analysis?
Answer:
5.13 g of CO₂.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
C₁₂H₂₂O + 17O₂ —> 12CO₂ + 11H₂O
Next, we shall determine the mass of C₁₂H₂₂O that reacted and the mass of CO₂ produced from the balanced equation. This can be obtained as follow:
Molar mass of C₁₂H₂₂O = 182 g/mol.
Mass of C₁₂H₂₂O from the balanced equation = 1 × 182 = 182 g
Molar mass of CO₂ = 12 + (2×16)
= 12 + 32
= 44 g/mol
Mass of CO₂ from the balanced equation = 12 × 44 = 528 g
SUMMARY:
From the balanced equation above,
182 g of C₁₂H₂₂O reacted to produce 528 g of CO₂.
Finally, we shall determine the mass of CO₂ produced from the reaction. This can be obtained as follow:
From the balanced equation above,
182 g of C₁₂H₂₂O reacted to produce 528 g of CO₂.
Therefore, 1.77 g of C₁₂H₂₂O will react to produce = (1.77 × 528)/182 = 5.13 g of CO₂.
Thus, 5.13 g of CO₂ were obtained from the reaction.
When Lithium chloride is dissolved in water, there is a steep rise in the temperature of the water. Based on the evidence, is the dissolution of lithium chloride endothermic, exothermic, or neither? Explain.
Answer:
When some LiCl is dissolved in water, the temperature of the water increases. This means that: (A) the strength of the intermolecular forces between the water molecules is stronger than the bond energy within the LiCl lattice.
Explanation:
When Lithium chloride is dissolved in water, there is a steep rise in the temperature of the water. Based on this evidence, the dissolution of lithium chloride is exothermic.
What is an Exothermic reaction?An exothermic reaction may be defined as a type of reaction in which energy is liberated as a product in the form of light or heat. For these types of reactions, the overall standard enthalpy change ΔH⚬ is negative. It is one of the thermodynamic processes other than endothermic.
In the reaction, lithium intensely reacts with water in order to form lithium hydroxide and highly flammable hydrogen which liberated energy and leads to the steep rise in the temperature of the product compounds. This enhancement in the temperature is accurate evidence of an exothermic reaction.
Therefore, on the basis of the evidence that the reaction of lithium chloride in water causes a steep rise in the temperature of the water represents an exothermic reaction.
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Which of the following is an example of a physical change, but not a chemical change?
Answer:
Boiling Water
Explanation:
Boiling water is an example of physical change and not and not a chemical change because the water vapor still has the same molecular structure as liquid water.If the bubbles were caused by the decomposition of a molecule into gas then boiling would be a chemical change.
Answer:
A chemical change results from a chemical reaction, while a physical change is when matter changes forms but not chemical identity. Examples of chemical changes are burning, cooking, rusting, and rotting. Examples of physical changes are boiling, melting, freezing, and shredding
Explanation:
What happens to matter that is used up during photosynthesis?
It retains its form and mass.
It retains its form but increases in mass.
It changes to a new form of matter with less mass.
It changes to a new form of matter with the same mass.
Answer:
I am almost positive that it is D. I might be incorrect do i appoligise if i am.
Explanation:
Convert 3.93 x 10-22 grams of X4Z3 into molecules/formula units of the same compound. (Assume that the molar mass of X is 59.45 grams per mole and the molar mass of Z is 13.84 grams per mole.)
Assume that Avogadro's number is 6.022 x 1023. Report your answer to three decimal places.
Answer:
0.847 molecule.
Explanation:
From the question given above, the following data were obtained:
Mass of X₄Z₃ = 3.93×10¯²² g
Number of molecules of X₄Z₃ =?
Avogadro's number = 6.022×10²³ molecules
Next, we shall determine the molar mass of X₄Z₃. This can be obtained as follow:
Molar mass of X₄Z₃ = (4×59.45) + (3×13.84)
= 237.8 + 41.52
= 279.32 g/mol
Finally, we shall determine the number of molecules in 3.93×10¯²² g of X₄Z₃. This can be obtained as follow:
From Avogadro's hypothesis,
1 mole of X₄Z₃ = 6.022×10²³ molecules
But 1 mole of X₄Z₃ = 279.32 g
Thus we can say that:
279.32 g = 6.022×10²³ molecules
Therefore,
3.93×10¯²² g = 3.93×10¯²² × 6.022×10²³ / 279.32
3.93×10¯²² g = 0.847 molecule.
Thus, 3.93×10¯²² g of X₄Z₃ contains 0.847 molecule.
Consider a hypothetical metal that has a density of 11.6 g/cm3, an atomic weight of 157.6 g/mol, and an atomic radius of 0.127 nm. Compute the atomic packing factor if the unit cell has tetragonal symmetry; values for the and lattice parameters are 0.523 nm and 0.330 nm, respectively.
Answer:
[tex]APF(atomic packing factor)=0.31736[/tex]
Explanation:
From the question we are told that
Density of metal [tex]\rho=11.6 g/cm3[/tex]
Atomic weight of [tex]W=157.6 g/mol[/tex]
Atomic radius of [tex]r= 0.127 nm[/tex]
Lattice parameters=>[tex]x=0.523nm[/tex] and [tex]y=0.330 nm[/tex]
Generally the equation for atomic packing factor is mathematically given as
[tex]APF(atomic packing factor)=\frac{Spere's\ volume}{unit\ cell\ volume}[/tex]
[tex]APF(atomic packing factor)=\frac{N*VN}{VC}[/tex]
Generally the equation for number of atoms N is mathematically given as
[tex]N=\frac{\rho }{atomic raduis*Avacados constant}[/tex]
[tex]N=\frac{11.6 }{0.127*10^{-9}*6.02214086*10^{23} mol-1}[/tex]
[tex]N=4[/tex]
Therefore APF(atomic packing factor)
[tex]APF(atomic packing factor)=\frac{N*VN}{VC}[/tex]
[tex]APF(atomic packing factor)=\frac{4*\frac{4}{3} \pi (0.127)^3}{(0.523)^2 *0.330}[/tex]
[tex]APF(atomic packing factor)=0.31736[/tex]
A given compound has the following solubility properties. At room temperature, it is soluble in diethyl ether but insoluble in both ethanol and water. At higher temperatures, it is soluble in both diethyl ether and ethanol, but insoluble in water. Propose a procedure for purifying this compound by recrystallization.
Answer:
See explanation
Explanation:
If we desire to recrystallize the given compound then we must do the following;
1) Add the compound to ethanol and heat the system
2) As the solute dissolves, the solution is allowed to cool
3) The solution may be seeded or the vessel scratched to aid crystallization.
4) The pure crystals are now filtered out, washed and dried.
Remember that recrystallization has to do with dissolving a solute in a solvent in which it is only soluble at high temperature but insoluble at low temperature.
The solvent dissolves the impure solute while pure crystals emerges as the temperature decreases.
I need help with the bottom two pls The first answer I will mark brainliest
Answer:
I dunno, what is the answer
Explanation:
What is made when a salt is dissolved in water?
Answer:
water
Explanation:
the salt dissapears and turns
into vapor
Answer:
A solution is made when a solid (which we call a solute) dissolves into a liquid (that we call the solvent) one example of a solution is salt dissolved in water. The salt and water can be separated again by evaporation (the water will evaporate if left in a got place leaving the salt behind. I don't know if that was the answer that you were looking for
Deforestation happens when people try to provide more:
a) water
b) waste
c) timber
d) oxygen.
A reversible reaction is said to have reached equilibrium when which of the following conditions is established?
The given question is incomplete. The complete question is:
A reversible reaction is said to have reached equilibrium when which of the following conditions is established?
a. concentration of reactants and products are equal
b. opposing reactions cease
c. speeds of opposite reactions become equal
d. temperature of opposite reactions become equal
Answer: c. speeds of opposite reactions become equal
Explanation:
Equilibrium state is the state when reactants and products are present but the concentrations does not change with time.The state of equilibrium refers to the dynamic state as both forward and backwad reactions continue.
For a chemical equilibrium reaction, equilibrium state is achieved when the rate of forward reaction becomes equals to rate of the backward reaction.
Thus at chemical equilibrium, the amount of product and reactant remains constant because the rates of the forward and reverse reactions are equal.
Vinegar is sold as % acidity which means a weight/volume or w/v% calculation. The density of acetic acid is 1.05 g/ml and water is (effectively) 1.0 g/ml. Recollect (from CHMY121) the %w/v refers to a solution with a certain mass of additive made up to 100 mL with the addition of (in this case) water; or gramsofsolute100mLsolution The molar mass of Acetic Acid is 60.052 g/mol. What is the molarity of CH3COOH in water of a 5% acidity vinegar solution
Answer:
0.83M is molarity of the solution
Explanation:
In a 5% w/v solution of vinegar there are 5g of acetic acid per 100mL of solution. Or 50g per liter of solution. As molarity is defined as the moles of the solute (Acetic acid) per liter of solution we need to convert the 50g per liter to moles per liter using molar mass of acetic acid:
Molarity:
50g/L * (1mol / 60.052g) = 0.8326moles/L =
0.83M is molarity of the solutionA kerosene stove that produces 0.8 g/hr of carbon monoxide (CO) is used in a closed room with a volume of 200 m3. Fresh air enters the room at the rate of 40 m3/hr and stale air leaves at the same rate. Assuming complete mixing and that carbon monoxide is a conservative pollutant (i.e., does not undergo decay), determine the steady state CO concentration
Answer:
20 mg/m3
Explanation:
Given -
S = 0.8 g/hr
Q = 40m3/hr
V =200 m3
As we know, the steady state CO concentration is given by
Css = S/Q
= 0.8/(40m3/hr)
= 800 mg/hr/(40m3/hr)
= 20mg/m3
Sound waves travel better through solid than through a gas. Example why this is true
Answer:
This is because molecules in a solid are packed against each other. When a vibration begins, the molecules of a solid immediately collide and the compression wave travels rapidly.
Explanation:
What important function do currents and areas of upwelling provide for living things
in the sea?
Recycles the ocean water through evaporation and precipitation
Brings nutrients up from deeper water for use by organisms
Mixes land and sea organisms to broaden the food web
Allows Earth to have weather and climate changes
What is the concentration of lithium ions in 0.400 M Li₂HPO₄?
Answer: 0.800 M
Basically, the ratio is 2:1, so when you have 1 M of Li2HPO4 it means you have 2 M in the concentration of lithium ions. So knowing the ratio, we know we just need to multiply 0.400 x 2.
I'm bad at explaining it, but got it right on chem101 sooo
The concentration of lithium ion, Li⁺ in 0.4 M Li₂HPO₄ is 0.8 M.
The concentration of a substance is simply the amount of the substance in 1 L of water.
To obtain the concentration of lithium ion, Li⁺ in Li₂HPO₄, we'll begin by writing the dissociation equation of Li₂HPO₄. This is illustrated below:
Li₂HPO₄ (aq) <=> 2Li⁺(aq) + HPO₄²¯(aq)From the balanced equation above,
1 mole of Li₂HPO₄ produced 2 moles of Li²⁺.
Finally, we shall determine the concentration of lithium ion, Li⁺ in 0.4 M Li₂HPO₄. This can be obtained as follow:
From the balanced equation above,
1 mole of Li₂HPO₄ produced 2 mole of Li⁺.
Therefore, 0.4 M Li₂HPO₄ will produce = 2 × 0.4 = 0.8M Li²⁺
Thus, 0.8 M lithium ion, Li⁺ is present in the solution.
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Convert 8.876 × 10^12 m^2 to units of km^2.
Answer:
[tex]8.876\times 10^{18}\ km^2[/tex]
Explanation:
In this problem, we need to convert [tex]8.876 \times 10^{12}\ m^2[/tex] to km².
We know that,
1 km = 1000 m
⇒ 1 km² = 10⁶ m²
So,
[tex]8.876 \times 10^{12}\ m^2=8.876 \times 10^{12}\times 10^6\ km^2\\\\=8.876\times 10^{18}\ km^2[/tex]
So, [tex]8.876 \times 10^{12}\ m^2[/tex] is equal to [tex]8.876\times 10^{18}\ km^2[/tex].
Here’s the answers I wasn’t asking a question hehe!Subtract the mass of the filter paper (0.27g) from the mass of the paper and copper (0.98 g). Record the difference in the data table as the amount of copper.
You already converted mass to moles for the reactants. Now convert mass to moles for the product, copper
all for edge
ANSWERS!!!
How to get the density of this unknown liquid?
Answer:
Measure the volume of water poured into a graduated cylinder, then place the object in the water and remeasure the volume. The difference between the two volume measurements is the volume of the object. Now simply divide the mass by the volume to calculate the density of the object.
Disaccharides are held together by a glycosidic bond. Hydrolysis of the disaccharide requires_____
Answer:
monosaccharides and glycosidic, I think
Explanation:
Answer:
pasagottt po plss
Explanation:
edi wow
The diagram illustrates photosynthesis.
Which best describes what is happening in the area marked X?
Carbon dioxide enters the stem through xylem.
Oxygen enters the stem through stomata.
Water is carried to the leaves by stomata.
Water is carried to the leaves by xylem.
Answer:
I think Water is carried to the leaves by xylem.
Answer:
d
Explanation:
3. Match each of the following descriptions with one of the beakers in Model 1. In each case, assume the change in volume as the solid(s) are added is minimal. a. A 1.00 mole sample of solid calcium hydroxide is added to 500.0 mL of water in beaker . b. A 1.00 mole sample of solid calcium hydroxide is added to 500.0 mL of 0.500 M sodium hydroxide solution in beaker . c. A 1.00 mole sample of solid calcium hydroxide is added to 500.0 mL of 0.200 M sodium hydroxide solution in beaker . d. A 1.00 mole sample of solid calcium hydroxide is added to 500.0 mL of 0.200 M calcium nitrate solution in beaker . 4. Based on the solubility product constant, Ksp, for calcium hydroxide given in Model 1, do you expect most of the 1.00 mole sample of solid to dissolve in any of the four beakers
Answer:
Explanation:
When calcium hydroxide is dissolved in water , it ionizes as follows .
Ca( OH)₂ = Ca⁺² + 2 OH ⁻
When it is dissolved in water which contains minimal OH⁻ , so there is almost no common ion effect . Hence calcium hydroxide is fully dissolved in pure water solvent .
When 1.00 mole sample of solid calcium hydroxide is added to 500.0 mL of 0.500 M sodium hydroxide solution in beaker , it is not fully dissolved due to common ion of hydroxide ion ( OH⁻ )
NaOH = Na⁺ + OH⁻
OH⁻ ion from NaOH , suppresses the dissolution of calcium hydroxide .
Similarly
When A 1.00 mole sample of solid calcium hydroxide is added to 500.0 mL of 0.200 M sodium hydroxide solution in beaker , it is not fully dissolved due to common ion of hydroxide ion ( OH⁻ )
NaOH = Na⁺ + OH⁻
OH⁻ ion from NaOH , suppresses the dissolution of calcium hydroxide
When 1.00 mole sample of solid calcium hydroxide is added to 500.0 mL of 0.200 M calcium nitrate solution , it is not fully dissolved due to common ion of calcium ion ( Ca⁺² )
Ca( NO₃)₂ = Ca⁺² + 2NO₃⁻
Ca⁺² ion from Ca( NO₃)₂ , suppresses the dissolution of calcium hydroxide .
