Which product will precipitate in the following reaction:
CaCl2 + Na2CrO4 → CaCrO4 + 2 NaCl
A.NaCl
B.CaCrO4
C.Na2CrO4
D.CaCl2
Answer:
a
Explanation:
For each process, predict the sign on the entropy change and write a sentence or two to explain how to make this prediction without completing any mathematics. a.A solid melts. b.A vapor is converted into a solid. CH 117 Recitation Name: _________________________________ ~ 196 ~ c.A liquid freezes. d.A solid sublimes e.A vapor condenses to a liquid. f.A liquid boils. g.Dissolving a tablespoon of salt in water. h.Combustion of gasoline.
Answer: a. A solid melts: [tex]\Delta S=+ve[/tex]
b. a vapor is converted to solid: [tex]\Delta S=-ve[/tex]
c. a liquid freezes: [tex]\Delta S=-ve[/tex]
d. A solid sublimes: [tex]\Delta S=+ve[/tex]
e. a vapor condenses to liquid : [tex]\Delta S=-ve[/tex]
f. a liquid boils: [tex]\Delta S=+ve[/tex]
g. dissolving a tablespoon of salt in water: [tex]\Delta S=+ve[/tex]
h. combustion of gasoline: [tex]\Delta S=+ve[/tex]
Explanation:
Entropy is the measure of randomness or disorder of a system. If a system moves from an ordered arrangement to a disordered arrangement, the entropy change is negative and vice versa.
a. A solid melts: The solid is converting to liquid, thus the randomness is increasing as the molecules are moving away and the intermolecular forces are getting weaker. Thus the entropy change [tex](\Delta S)[/tex] is positive.
b. a vapor is converted to solid: The gas is converting to solid, thus the randomness is decreasing as the molecules are moving close and the intermolecular forces are getting stronger Thus the entropy change [tex](\Delta S)[/tex] is negative.
c. a liquid freezes: The liquid is converting to solid, thus the randomness is decreasing as the molecules are moving close and the intermolecular forces are getting stronger. Thus the entropy change [tex](\Delta S)[/tex] is negative.
d. A solid sublimes: The solid is converting to gas, thus the randomness is increasing as the molecules are moving away and the intermolecular forces are getting weaker. Thus the entropy change [tex](\Delta S)[/tex] is positive.
e. a vapor condenses to liquid : The gas is converting to liquid, thus the randomness is decreasing as the molecules are moving close and the intermolecular forces are getting stronger. Thus the entropy change [tex](\Delta S)[/tex] is negative.
f. a liquid boils: The liquid is converting to gas, thus the randomness is increasing as the molecules are moving away and the intermolecular forces are getting weaker. Thus the entropy change [tex](\Delta S)[/tex] is positive.
g. dissolving a tablespoon of salt in water: The solid is converting to ions , thus the randomness is increasing as the ions can move freely. Thus the entropy change [tex](\Delta S)[/tex] is positive.
h. combustion of gasoline: The liquid is converting to gas, thus the randomness is increasing as the molecules are moving away and the intermolecular forces are getting weaker. Thus the entropy change [tex](\Delta S)[/tex] is positive.
Q3: Match the column A with Column B and write answer in Column C
Answer:
ok
Explanation:
1d
2c
3b
4a
Ali says the climate of a town is rainy because it is raining outside today. Is she correct? In one or two sentences, explain why Ali is or is not correct about the climate of the town.
Answer:
Ali is incorrect.
Explanation:
Ali is wrong because the climate is a study of the weather pattern over a long period of time. You cannot look outside one day and determine the climate because the climate is long-term.
She could say the weather is rainy, because that is short term, but not the climate.
How is the molar mass of an element determined?
O A. The atomic mass unit times Avogadro's number is the molar
mass.
B. The number of moles in grams is the molar mass of the element.
C. The atomic mass in g/mol is the molar mass of the element.
D. The atomic number in g/mol is the molar mass of the element.
1.Calculate the percentage of the components of the compounds resulting from the following reactions
(A) 222.6g N combined fully with 77.4g of O.
(B) Decomposition of table salt which yields 2.62g of Na and 4.04g of Cl.
Answer:
Explanation:
I believe its A
Describe two realistic demands protestors could bring forward in their peaceful protest so that they dont face the same situation in future
Answer:
I do not know the Answer I'm just trying to get my point
Explanation:
Thank You
The two realistic demands protestors could bring forward in their peaceful protest include:
Adequate securityProvision of social amenities.Who is a Protester?Thus it is referred to an individual which publicly demonstrates opposition to something.One of the roles of the government is to protect lives and properties.
Making realistic demands during a peaceful protest is looked into in most cases.
Read more about Protester here https://brainly.com/question/11505871
how is the periodic table important for all of science and not just chemistry? pleas answer me
Answer:
The periodic table has been there for such a long time and how it is helpful in all science it is the element itself. How the element is used in real life. For example, oxygen is used in the atmosphere. Plants use carbon in order to covert it into oxygen more like that
What is the air pressure on top of the mountain?
Explanation:
At sea level, the atmospheric pressure would be a little over 100 kPa (one atmosphere or 760 mm Hg). If we climb to the top of Mount Everest (the highest mountain in the world at 29,029 feet or 8848 meters), the atmospheric pressure will drop to slightly over 30 kPa (about 0.30 atmospheres or 228 mm Hg).
Hope it is helpful for you
What is the cation in KF?
Answer:
K, or Potassium
Explanation:
WILL AWARD BRAINLIEST! I NEED HELP PLEASE! Match the states of matter for each of the five lines below.
Answer:
see explanations
Explanation:
The graphic is the heating curve for water. Note that it is divided into 5 distinct heat flow segments. The segments with changing slopes are single phase segments with changes in temperature values. From left to right segment A is solid ice being warmed to it's melting point. Segment B is the melting segment in which 2 phases are in contact (solid + liquid). Note that addition of heat does not change the temperature. Segment C is warming of the liquid (single phase) up to its boiling point. At the boiling point the liquid begins to pass into the gas phase and again 2 phases are in contact; i.e., liquid & gas. Note again when two phases are in contact no temperature change occurs. Finally, segment E is the heating of the pure, single phase gas.
In summary ...
Segment A => heating single phase (solid) ice up to melting pt.
Segment B => melting of ice => 2 phases in contact (s & l) ΔT = ∅.
Segment C => heating single phase (liquid) water up to boiling pt.
Segment D => boiling of liquid => 2 phases in contact (l & g). ΔT = ∅.
Segment E => heating single phase (steam) up to desired temperature.
For what it's worth, the equation for the segments that show increasing temperature values is q = mcΔT (m= mass, c = specific heat & ΔT temp change.
The segments with zero slopes (horizontal lines) are defined by equations q = m·ΔHₓ where m = mass & ΔHₓ = heat of fusion (a constant = 335 j/g). The same is true for the line at 100°C where q = m·ΔH(v) where m = mass & ΔH(v) is the heat of vaporization (a constant = 2259 j/g.
Calculations involve calculating the amount heat transfer for each segment individually and then adding the heat values to obtain the total heat transfer.
If you need more instruction on this topic, kick back a note and I'll try to help clarify. Good Luck, Doc :-)
Answer:
Picture attached has answers
Explanation:
HELP PLEASEEEEEE ASAP
A condition in which bones become weak and brittle.
The body constantly absorbs and replaces bone tissue. With osteoporosis, new bone creation doesn't keep up with old bone removal.
thus 2) is correct.
a disease in which bone tissue becomes breakable and thin.
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Why are half-reactions used in redox reactions?
Answer:
Because a redox reaction holds for both oxidation and reduction.
One half equation is of oxidation and the other is of reduction.
When these two half equations are combined, we get an overall equation of the redox reaction.
23. Forces accelerate objects. Newton's second law state that force equals ______times?
Answer:
F = ma, or force is equal to mass times acceleration.
Electrophilic substitution occurs
Answer:
I hope it's helpful for you....
Explanation:
Electrophilic substitution reactions are chemical reactions in which an electrophile displaces a functional group in a compound, which is typically, but not always, a hydrogen atom.
Which is an application of genetic engineering?
A.
destroying all bacteria
B.
creating synthetic insulin
C.
producing cells from nonliving material
D.
preventing weeds from spreading to farmland
Answer:
B. Creating synthetic insulin
Explanation:
In medicine, genetic engineering has been used to mass-produce insulin, human growth hormones, Follistim (for treating infertility), human albumin, monoclonal antibodies, antihemophilic factors, vaccines, and many other drugs. In research, organisms are genetically engineered to discover the functions of certain genes.
Psychology is the study of the human brain. A psychoanalyst is a person who
analyzes people's minds. What does the prefix psycho-mean?
A. Related to the brain
B. Related to studying
C. Related to science
D. Related to analysis
In the context of a balanced chemical equation, a____is a number to the lower right of an element or ion within formula and it applies to____. A____is a number to the left of a formula and it applies to_____. Only_____should be added or changed when balancing chemical equations.
Answer:
Explanation:
The preceding chapter introduced the use of element symbols to represent individual atoms. When atoms gain or lose electrons to yield ions, or combine with other atoms to form molecules, their symbols are modified or combined to generate chemical formulas that appropriately represent these species. Extending this symbolism to represent both the identities and the relative quantities of substances undergoing a chemical (or physical) change involves writing and balancing a chemical equation. Consider as an example the reaction between one methane molecule (CH4) and two diatomic oxygen molecules (O2) to produce one carbon dioxide molecule (CO2) and two water molecules (H2O). The chemical equation representing this process is provided in the upper half of Figure 1, with space-filling molecular models shown in the lower half of the figure.
A student prepares a aqueous solution of butanoic acid . Calculate the fraction of butanoic acid that is in the dissociated form in his solution. Express your answer as a percentage. You will probably find some useful data in the ALEKS Data resource.
Answer:
15.4%
Explanation:
If Ka = 0.54 mM = 1.51x10⁻⁵
Then;
C₄H₈O₂ --------> C₄H₇O₂⁻ + H⁺
I 0.54x10⁻³ 0 0
E 0.54x10⁻³(1-x) 0.54x10⁻³x 0.54x10⁻³x
Recall that x is the percentage degree of dissociation
From the ICE table;
Ka = [C₄H₇O₂⁻] [ H⁺]/[C₄H₈O₂]
1.51x10⁻⁵=(0.54x10⁻³x) (0.54x10⁻³x)/ 0.54x10⁻³(1-x)
1.51x10⁻⁵ = 0.54x10⁻³x^2/1-x
1.51x10⁻⁵(1-x) = 0.54x10⁻³x^2
1.51x10⁻⁵ - 1.51x10⁻⁵x = 0.54x10⁻³x^2
Hence;
0.54x10⁻³x^2 + 1.51x10⁻⁵x - 1.51x10⁻⁵=0
x^2 + 0.028x - 0.028 = 0
Solving the quadratic equation here;
x = 0.154 or −0.182
Ignoring the negative result, x = 0.154
Hence, fraction of butanoic acid that is in the dissociated form in this solution = 15.4%
Given the following chemical reaction:
N2 + 202 --> 2 NO2
How many liters of N2 are needed to react with 10 liters of Q? Explain
Answer:
1
Explanation:
one volume of nitrogen to react
What physical property of matter determines the earth ?
Answer:
Density is a physical property that is determined by dividing the mass of a given amount of a substance by its volume.
Explanation:
1.
Why are kilometers not a good unit of measurement in space?
T.
2.
What distance measurement unit is used for objects within our solar system?
astronomical
units
3.
How many kilometers are in one astronomical unit?
4.
What distance measurement unit is used for objects outside of our solar
system?
_light
year!
5.
How many kilometers are in one light-year? I
How far away is the nearest star to Earth other than our Sun?
6.
7.
How far away is the center of the Milky Way Galaxy from Earth?
8.
What is the diameter of the Milky Way Galaxy?
true or false atoms can be made up of just one type of atom
Answer:
false
Explanation:
A compound has the combined properties of the elements from which it is made. Atoms show the macro properties of an element.
A gas under a pressure of 9.86 kPa and at a temperature of 75°C occupies a 500.0L container. How many moles of gas are in the container?
Answer:
1.7 mol
Explanation:
This is an ideal gas problem. So many units! That's the tip-off usually.
PV=nRT
First convert kPA to atm 1 atm=101.3 kPA so 9.86/101.3 = .097311 atm
(.097311 atm x 500L) = n · 0821 L·atm/mol·K · 348K
Do your multiplication then divide to get n alone and you should get 1.7 mol
What is a renewable resource on Earth?
minerals
coal
wind
petroleum
Answer:
Wind
Explanation:
Wind turbines make energy by the movement of the natural force on earth called 'wind' and renewable resources are resources that can be made from natural and environment-safe objects or things (e.g. Water, Geothermal Heat, The Sun, and Wind)
Pls help I’ll brainlest and add extra points
Determine the molar mass of a compound that has a density of 1.25 g/L at
STP. *
*
Answer:
So, weight per litre (1.25g/l) times 22.4 l/mole equals the mole weight (28 g/mole).
SO2 + PCL5 → SOCL2 + POCL3
What mass of SOCL2 is produced when 1.35 g SO2 react with 2.75 g PCL5
Answer:
2.34
Explanation:
explain what is ment by solvent front
Answer:
In paper chromatography, the wet moving edge of the solvent that progresses along the surface where the separation of the mixture is occurring.
Explanation:
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Is anyone good at chemistry if so can someone help me please ?
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This requires familiarity with the different theories (or concepts) of acids and bases.
On the Arrhenius concept, an acid is a substance that produces an H⁺ ion in water such that the H⁺ concentration increases, and a base is a substance that produces an OH⁻ ion in water such that the OH⁻ concentration increases.
On the Brønsted–Lowry concept, an acid is a substance that donates a proton (which is basically an H⁺ ion) in a solvent, and a base is a substance that accepts a proton in a solvent.
On the Lewis concept, an acid is a substance that accepts an electron pair in a solvent, and a base is a substance that donates an electron pair in a solvent.
The concepts become progressively broader, i.e., the Arrhenius concept is the most restrictive and the Lewis concept is the least restrictive. As a corollary, an Arrhenius acid or base is also both a Brønsted–Lowry acid or base and a Lewis acid or base, respectively; a Brønsted–Lowry acid or base is not necessarily an Arrhenius acid or base, but an Arrhenius acid or base is also a Lewis acid or base, respectively. And finally, a Lewis acid or base may not necessarily be either an Arrhenius or a Brønsted–Lowry acid or base.
So, with the above concepts in mind, we can match the statements in column A with the type of acid or base in column B:
[tex]\begin{center}\begin{tabular}{ c c } 1 & Bronsted Lowry acid \\ 2 & Bronsted Lowry base \\ 3 & Arrhenius acid \\ 4 & Arrhenius base \\ 5 & Lewis base \\ 6 & Lewis acid\end{tabular}\end{center}[/tex]
