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.
How many liters of SO2 will be produced from 26.9L O2?
Answer:
8 litres of SO2 will produced from 26.9L o2
Which solution is a homogeneous mixture?
sand and water
salt and water
salad dressing
soil
Answer:
soil
Explanation:
Name 3 ways you can keep our community healthy?
Answer:
1. Practice healthy habits with kids in your life. ...
2. Engage in your school's efforts to encourage healthy practices. ...
3. Learn more about the decisions local officials are making that impact your environment. ...
4. Give back healthy options to your community.
Explanation:
Which of these actions is an example of erosion caused by gravity?
A.
Constant freezing and thawing water forming a hole in an asphalt road
B.
Pieces of rock breaking off and falling from a mountain top
C.
Chemicals in the air dissolve minerals in a marble statue
D.
Plant roots widening cracks in a large granite rock
Answer:
The answer is a
Explanation:because yes
Answer: The answer is B.
Explanation: The rocks falling off is caused by gravity. Other options don't include effects of gravity; Therefore, B is correct.
Which of the following is a job that bones do?
a.provide the body with shape and protection
b.store minerals
c.produce supply of daily blood cells
d.all of the above
Answer:
a.Provide the body which shape and protection.
Explanation:
Bones usually gives us shape as well as protects our innner organs.
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a 55g block of metal has a specific heat of 0.45 J/g°C. What will be the temperature change of this metal if 450 J of heat energy are added
Answer:
18.18C
Explanation: Write whats below to show your work :D
m=55
C=0.45
Q=450zj
ch.temp=?
Q=mct
450 = (55)(.45)T
450 = 24.75
/24.75 = /24.75 (cancels out)
18.18 is the answer
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What is the empirical formula of the following molecular formula: C3H6
Answer:
CH2
Explanation:
The empirical formula is the lowest ratio form of a compound. You can divide both C and H by 3 to get to CH2.
Use Lewis theory to determine the chemical formula for the compound formed between Mg and Br. Group of answer choices Mg3Br2 Mg2Br3 Mg2Br MgBr2 MgBr
Answer:
MgBr2
Explanation:
(Mg^2+) + (Br^1-)
For every Mg we need 2 Br to balance out the compound.
Since magnesium has two outer electrons, it can donate one electron each to two bromine atoms having seven outer electrons in order for each of the atoms to have a complete octet.
Since the octet rule states that a stable atom must have eight electrons in its outermost shell, it follows that magnesium could give out two of its outermost electrons to two bromine atoms.
When that happens, each bromine atom which previously had seven electrons now have eight electrons, satisfying the octet rule. The correct formula of the compound is MgBr2.
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Franklin was performing an experiment by combining hydrochloric acid and sodium hydroxide. He measured the mass of his reactant materials to be 35g. The reaction resulted in the production of salt and water. He reported that his products weighed 32g. Which best describes the results of Franklin’s experiment? No error occurred, some of the products are always lost as heat. An error occurred, the mass of the reactants should equal the mass of the products. An error occurred, the products should weigh more than the reactants. No error occurred, water is not weighed when determining the weight of the products.
Answer:
B) an error occurred, the mass of the reactants should equal the mass of the products.
Explanation:
The answer choices are:
A) no error occurred, some of the products are always lost as heat.
B) an error occurred, the mass of the reactants should equal the mass of the products.
C) an error occurred, the products should weigh more than the reactants.
D) no error occurred, water is not weighed when determining the weight of the products.
SolutionThe basis to answer this question is the law of conservation of mass.
Any chemical reaction satisfies the law of conservation of mass: mass cannot be either created nor destroyed, so, always, the mass of the reactants equal the mass of the products.
Thus, since he measured the mass of his reactant materials to be 35g and he reported that his products weighed 32g, his data are in clear contradiction of the law of conservation of mass. So, there is an error in his results: the mass of the reactants should equal the mass of the products.
An error occurred, the mass of the reactants should equal the mass of the products according to law of conservation of mass for the given experiment. Therefore, the correct option is option B.
The mass of the reactants and products in a chemical reaction should be equal, in accordance with the law of conservation of mass. This implies that there is no net change in mass during the chemical process. The mass of the reactants and products in a chemical reaction should be equal, in accordance with the law of conservation of mass. This implies that there is no net change in mass during the chemical process.
Franklin determined the mass of the reactant components in this instance to be 35g, and the products of the reaction weighed 32g. An error occurred because the mass of the reactants should equal the mass of the products, but the mass of the products is less than the mass of the reactants.
Therefore, the correct option is option B.
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Which of the following chemical reactions will produce a precipitate?
3 KBr + AlPO4 → K3PO4 + AlBr3
Na2CO3 + CaCl2 → CaCO3 + 2 NaCl
NH4OH + KCl → KOH + NH4Cl
ZnCl2 + Mg2SO4 → ZnSO4 + MgCl2
Answer:
Na2CO3 + CaCl2 → CaCO3 + 2 NaCl
Explanation:
A double displacement reaction is a type of metathesis reaction in which two reactants exchange ions to form two new compounds. Double displacement reactions usually involve reacting two soluble salts in aqueous solution resulting in the formation of two products: a soluble salt and an insoluble salt that is produced as a precipitate.
If the reaction of two soluble compounds does not produce a precipitate, the reaction does not result in the formation of a product as basically, all the ions are mixed together in the reaction vessel.
From the given reactions above:
1. 3 KBr + AlPO4 → K3PO4 + AlBr3
The reaction does not proceed to product formation as the two products are all soluble salts.
2. Na2CO3 + CaCl2 → CaCO3 + 2 NaCl
The reaction occurs as one of the products, CaCO3 is insoluble as is produced as a precipitate.
3. NH4OH + KCl → KOH + NH4Cl
The reaction does nott occuras the products are all soluble in water.
4. ZnCl2 + Mg2SO4 → ZnSO4 + MgCl2
The reaction does not occur as the products are all soluble in water.
A hot metal plate at 150°C has been placed in air at room temperature. Which event would most likely take place
over the next few minutes?
Molecules in both the metal and the surrounding air will start moving at lower speeds.
Molecules in both the metal and the surrounding air will start moving at higher speeds.
The air molecules that are surrounding the metal will slow down, and the molecules in the metal will speed up.
The air molecules that are surrounding the metal will speed up, and the molecules in the metal will slow down.
Answer:
molecules will speed up
Explanation:
What is temperature?
Answer: Temperature is an objective measurement of how hot or cold an object is. It can be measured with a thermometer or a calorimeter. It is a means of determining the internal energy contained within a given system.
Explanation:
Answer:
Temperature is a physical quantity that expresses hot and cold
Explanation:
Temperature is a physical quantity that expresses hot and cold. This is how the air feels and how hot/cold something is. The less tight the atoms are, the hotter something is. The more tight the atoms are, the cooler something is.
A buffer solution is 0.439 M in CH3COOH and 0.311 M in CH3COONa . If K_a for CH2COOH is 1.8x10^-5, what is the pH of this
buffer solution?
Please no link answers!
Answer:
whats CH3COOH please tell me so I can answer!
What would this mechanism look like?
Answer:
Not sure sorry :(
Explanation:
Which type of formula shows an element symbol for each atom and a line for each bond between atoms?
structural
molecular
empirical
ionic
Answer: structural
Explanation:
When metals and non metals combine in fixed proportion then a chemical compound is formed. Structural formula shows an element symbol for each atom and a line for each bond between atoms. The correct option is option A.
What is chemical formula?Chemical formula is a formula where cation and anion combine to form a molecule in fixed proportion. Metals combine in form of cation and non metals combine in form of anion.
Cation is the species that give electron and attain positive charge while anion is a species which gain electron and attains negative charge so when anion and cation combine in fixed ration the the overall charge of the molecule is zero that is molecule is neutral.
Out of given structural is a 3D representation of any chemical formula, in which symbol of each element is shown .Along with symbol line for each bond between atoms is also shown.
Therefore, the correct option is option A.
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Please balance the equation C7H16 + CoF3 = C7F16 + HF +CoF2
with solutions
b. how many grams of CH6 is needed to react with 20.0 grams of HF?
C. how many particles of CoF3 is needed to react with 40.0 grams of CzF16?
d. how many grams of CH16 will be produce from 2.03 x 10 molecule of CoFs?
e. Find the Limiting reactant and exXcess reactant in CF16?
6g of CH16
6g of CoFa
f. Find the theoretical yield from CzFi6?
g. What is the percent yield of C;F16 if the actual yield is 1.28 g ?
What is the balanced molecular equation and balanced chemical equation for NaSO4 and KNO3?
Answer:
=KSO4+Na2(NO3)2
Explanation:
the answer is true using this chemical equation balancer
4. How many atoms are in 1.73 moles of copper(I) oxide?
wish in new Explanation:
[80 POINTS] Which reaction will most likely take place based on the activity series?
Answer:
Li + ZnCO3
Explanation:
Li is higher than Zn on the activity series so Ln is more easily oxidized and prefers to be in a compound. For the rest of the reactions, the element that is higher on the activity series is already in the compound, so the reactions wouldn't happen.
Answer:
C. Li + ZnCO3
Explanation:
edge 2021
What mineral property is being tested below?
Answer:
Streak
Explanation:
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Fires are classified into various classes and as such different types of portable fire extinguishers must be used. The theory behind portable fire extinguishers is that the fire can be extinguished by removing any or more of the following four elements:
Fuel, Heat, Oxygen, Chain Reaction.
Identify the extinguishing mechanism and the classe(s) of fires they are used to extinguish for the following types of fire extinguishers:
ABC Powder, Carbon dioxide, Foam, Water.
Answer:
Explanation:
ABC Powder: sprays a very fine chemical powder. This acts to blanket the fire and suffocate it. Class A, B, C fires
Carbon dioxide: extinguishes CO2. By doing so, it removes oxygen from the fire, effectively suffocating it of oxygen. Class B fires
Foam: spray a type of foam that expands when it hits the air and blankets the fire. This prevents the vapors from rising off the liquid to feed the fire, thus starving it of fuel. Class A and B
Water: releases microscopic water molecules that fight the fire on a variety of levels. the level of oxygen in the air is decreased, which helps to suffocate the fire. Class: most all
also, your fire classes:
Class A: freely burning, combustible solid materials such as wood or paper
Class B: flammable liquid or gas
Class C: energized electrical fire (energized electrical source serves as the ignitor of a class A or B fire – if electrical source is removed, it is no longer a class C fire)
Class D: metallic fire (titanium, zirconium, magnesium, sodium)
Class K: cooking fires – animal or vegetable oils or fats
Calculate the OH-ion concentration of a 6.2x10-3 M HCIO3 solution.
Answer:
1.62x10⁻¹² M
Explanation:
HClO₃ is a strong acid, meaning that a 6.2x10⁻³ M solution has a molar concentration of H⁺ of 6.2x10⁻³.
With the above information in mind, we can calculate the pH of the solution:
pH = -log(6.2x10⁻³) = 2.21Now we can calculate the pOH of the solution, using the pH:
pOH = 14 - pHpOH = 11.79Finally we calculate [OH⁻], using the definition of pOH:
pOH = -log[OH⁻][OH⁻] = [tex]10^{-pOH}[/tex] = 1.62x10⁻¹² Mif a sample is 0.5g but has an impurity of 70% what is the real mass of the sample(pure)?
Answer:
0.15
Explanation:
0.5 is100% of the total mass if 70% is impure .find the mass of 70%
which is 0.35g take 0.5 -0.35 =0.15
0.15 is the mass of the pure sample
Pure substance uniform
How many moles of water are produced from the reaction of 0.224 mol oxygen according to this equation? 2H2 + O2 -> 2H2O
Answer:
0.448 mols
Explanation:
Use balanced equation:
2H2 + O2 -> 2H2O
For every one mole of oxygen, there are two moles of water
hence the molar ratio 1:2
So if there are 0.224 mols of oxygen
Water = 0.224×2
Which is 0.448 mols of H20
What is the temperature of the gas inside a 750 ml balloon filled with 0.30 g hydrogen gas? The pressure of the balloon is 1.2 atm.
Why is it expensive to bring electricity into urban areas?
Answer:
Power plants are not located in cities. Power has to travel a long distance over power lines to reach cities.
Explanation:
Which product will precipitate in the following reaction:
CaCl2 + Na2CrO4 → CaCrO4 + 2 NaCl
A.NaCl
B.CaCrO4
C.Na2CrO4
D.CaCl2
Answer:
a
Explanation:
Calculate the number of total atoms in 195 grams of Ni(OH)2.
1.267 x 10 ^ 24 is the total number of atoms
The parts of DNA that give instructions for making proteins are called ________.
a genes
b dominant trait
c recessive trait
d mutation
Answer:
A
Explanation:
Each DNA sequence that contains instructions to make a protein is known as a gene. The size of a gene may vary greatly, ranging from about 1,000 bases to 1 million bases in humans.