Answers
Answer:
Q1= 9.42
Q2= 227 KJ
Q3= 31.4 KJ
Qt=269 KJ
Explanation:
First you have to find the heat needed to make ice at a temperature of -45 C to pass to a temperature of 0 C.
You're given the formula so all you have to do is replace by the data you're given (remember to make the Celsius, Kelvin by adding 273.15 to the Celsius since the magnitudes of temperature they're giving you in the constants are the Kelvin)
Q1= (2.093 J/gxK)(100 g)(45 K)
Q1=9418.5 J
Q1=9.4185 KJ≈9.42 Kj(you're asked to give your answer in KJ)
You know have to find the energy needed to liquify the ice, in other words you need to use the enthalpy of fusion to determine the energy that's being used, and since you have 100 grams of water, you only need to find the number of moles present in 100 grams of water by dividing the number of grams by the molar mass of water (18 g/mol) and then replace in the equation.
Q2=(5.56 mol)(40.7 KJ/mol)
Q2=227 KJ
You know have to find the energy needed to raise the temperature of water from 0 C to 75 C. You do the same thing as you did in the first step:
Q3=(4.184 J/gxK)(100 g/)(75K)
Q3=31380 J
Q3=31.38 KJ≈31.4 KJ
For the final step, you only add the Qs of each step:
9.42KJ+227KJ+31.4KJ= 267.82 KJ ≈ 267.8 KJ
Why do you use these procedures?
Well, you could simply have made a unique equation at first sight that involved the changes of temperature from -45 C to 75 C, but you have a phase change in the middle. Phase change keep temperature constant but they require heat from the surroundings in order to, in the case of ice, break the bonds that keep the molecules tight together.
This heat required from the surroundings is the Enthalpy of phase change, in this case enthalpy of fusion.
Related Questions
What is one element that is not found in the human body, air, or the universe? Brainliest to whoever gets it right! PLEASE HELP! :) 20 points for the question also! :D
Answers
Answer:
Technetium. It is only found in the stars.
Explanation:
Sorry, but thats all I could find for tou
The are many elements which are not present in human body. But almost all the discovered elements are there in the universe. But the one which is not present in earth and air is technetium
What is an technetium ?Technetium is the first synthesized element by man in 1937. Technetium has no stable isotopes and it is not found in earth. But it is present in stars. However, rare earth elements such as promethium , francium etc. can be prepared or observed from uranium ores.
There are many elements especially some actinides and lanthanides which are not present in earth naturally existence on starts and other planets.
Human body is made of various elements including carbon, oxygen, nitrogen, various metals like iron, zinc etc. Various enzymes contains different elements but the number of elements which are in the surroundings of human and not inside is larger.
Therefore, all the discovered elements are found in the universe and some them are not present in earth.
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Fast pls due rn help fast pls
Answers
Answer:
Section a:
1. stratosphere
2. radio waves
3. nitrogen, oxygen
4. humidity
5. smoke, fog
Section b:
1. ozone layer
2. stratosphere
3. carbon dioxide (CO2)
4. smoke
5. tropical areas
Section c:
1. false, it is clear
Hope those help and are all correct
BRAINLIEST TO FIRST RIGHT ANSWER
Students were investigating heat transfer by conduction and they set up the simple experiment you see here. They utilized three spoons made of different materials: the specific heat capacity of each material was recorded in the students' data table. Each spoon was placed in a pot of hot (90°C) water and a pat of butter was placed on the handle of each spoon. The butter melted first on the tin spoon and in about the same amount of time on the plastic and wood spoons. Based on the data table and the experimental results select ALL of the conclusions that are appropriate.
A) Conduction occurred more readily in the tin due to its lower specific heat
capacity
B) Heat transfer via conduction occurred from the hot water to the spoons
and then to the butter,
C) When in contact with hot water, there was no transfer of kinetic energy
through the wood or plastic
D) The atoms in the tin spoon vibrated and collided at a greater rate thon
those in the wood or plastic spoons
E) In all three cases energy s transferred from the faster moving hot water
molecules to the slower moving molecules in the spoon
Answers
Answer:
the Answer is A B D
Explanation:
the cunduction in the spoons are equal to all the following answers
Conduction occurred more readily in the tin due to its lower specific heat capacity, Heat transfer via conduction occurred from the hot water to the spoons and then to the butter, The atoms in the tin spoon vibrated and collided at a greater rate thon those in the wood or plastic spoons. Thus option A,B, D are correct.
What is specific heat ?
Specific heat can be measured as the quantity of heat required to increase the temperature of one gram of a substance by one degree Celsius.
The units of specific heat are represented as calories or joules per gram per Celsius degree such as the specific heat of water is 1 calorie per gram per Celsius degree
Specific heat capacity= Heat quantity/ mass × change in temperature.
If Q is the quantity of heat in joules, M is the mass of substance heated,
If ∆O is the change in temperature in Kelvin, Then Q= MC∆O, C is a constant called Specific heat capacity. Therefore, making C the subject of formula:
C= Q /M∆O
Thus option A,B, D are correct.
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Help with this worksheet please (24pts)
Answers
Hope you could get an idea from here.
Doubt clarification - use comment section.
HELP PLEASE ASAP ILL GIVE BRAINLEST
Answers
Answer:
D
Explanation:
braineist pls???????????
Answer:
C
Explanation:
gram is bigger than atom duh
AC current is produced by which of the following things?
A. Remotes
B. Generators
C. Lights
D. Lasers
Answers
Answer:
B
Explanation:
how many grams are in 4.07x10^15 molecules of calcium hydroxide
Answers
There are 5.01 × 10-⁷grams in 4.07 x 10¹⁵molecules of calcium hydroxide.
HOW TO CALCULATE MASS:
The mass of a substance can be calculated by multiplying the number of moles in the substance by its molecular mass.
However, given that the number of molecules in calcium hydroxide is 4.07 x 10¹⁵molecules, we need to calculate the number of moles in Ca(OH)2 as follows:
no. of moles of Ca(OH)2 = 4.07 x 10¹⁵ ÷ 6.02 × 10²³
no. of moles = 0.676 × 10-⁸
no. of moles = 6.76 × 10-⁹ moles.
Molar mass of Ca(OH)2 = 74.093 g/mol
Mass of Ca(OH)2 = 74.093 × 6.76 × 10-⁹ moles
Mass = 5.01 × 10-⁷grams.
Therefore, there are 5.01 × 10-⁷grams in 4.07 x 10¹⁵molecules of calcium hydroxide.
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factors that affect the rate of a chemical reaction include which of the following? i. frequency of collisions of reactant particles ii. kinetic energy of collisions of reactant particles iii. orientation of reactant particles during collisions
Answers
To solve such this we must know the concept of double displacement reaction. Therefore, the correct option is option B that is kinetic energy of collisions of reactant particles.
What is chemical reaction?Chemical reaction is a process in which two or more than two molecules collide in right orientation and energy to form a new chemical compound. The mass of the overall reaction should be conserved. There are so many types of chemical reaction reaction like combination reaction, double displacement reaction.
There are so many factors that affects the rate of reaction, among these, kinetic energy of collisions of reactant particles affect the rate of a chemical reaction. the rate of reaction is directly proportional to the rate of chemical reaction.
Therefore, the correct option is option B.
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is change in color a physical change
Answers
Answer: A change in color is not always a chemical change. If one were to change the color of a substance in a non-chemical reaction scenario, such as painting a car, the change is physical and not chemical.
Solid → Liquid: Melting
Solid → Gas: Sublimation
Liquid → Gas: Vaporization
Gas → Liquid: Condensation
Explanation:
A small container of perfume is opened in a classroom. Soon every student in the room smells the perfume. Explain this in terms of molecules.
Answers
Answer: possibly diffusion
Explanation:
all particles are in motion unless at a certain degree so they'd spread throughout the room diluting as they continue to spread out.
. A sample of ammonium phosphate can be prepared by the reaction of aqueous ammonia and phosphoric acid. 3NH3 (aq) + H3PO4 (aq) (NH4),PO4 (aq) 25.0cm of 1.25 mol/dm phosphoric acid is neutralised by 45.3cm of aqueou ammonia (a) Calculate the concentration in mol/dm3 of the ammonia used.
Answers
The concentration in mol/dm³ of the ammonia used is 2.07 mol/dm³
Balanced equation3NH₃ (aq) + H₃PO₄ (aq) -> (NH₄)₃PO₄ (aq)
From the balanced equation above,
The mole ratio of the acid, H₃PO₄ (nA) = 1The mole ratio of the base, NH₃ (nB) = 3How to determine the molarity of NH₃ Volume of acid, H₃PO₄ (Va) = 25 cm³Molarity of acid, H₃PO₄ (Ma) = 1.25 mol/dm³Volume of base, NH₃ (Vb) = 45.3 cm³ Molarity of base, NH₃ (Mb) = ?MaVa / MbVb = nA / nB
(1.25 × 25) / (Mb × 45.3) = 1 / 3
31.25 / (Mb × 45.3) = 1 / 3
Cross multiply
Mb × 45.3 = 31.25 × 3
Divide both side by 45.3
Mb = (31.25 × 3) / 45.3
Mb = 2.07 mol/dm³
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Explain why the melting temperature of boron trichloride is much lower than that of sodium chloride
Answers
whereas sodium chloride has a giant ionic lattice
structure. The ionic bonding between oppositely
charged ions in NaCl is stronger than the covalent
intramolecular bonding in BCl3. Therefore, less energy
is required to break the intramolecular covalent bonds in
BCl3, hence a lower melting temperature.
How did President Wilson anger civil rights advocates?
Answers
Answer:
He put segregationists in charge of federal agencies...
Explanation:
...
Answer:
He placed segregationists in charge of federal agencies.
Explanation:
What rule predicts the, stability of a atoms forming compounds.
Answers
Answer:The octet rule
Explanation:that there is eight electrons in the valence shell to make it stable.
Explanation:
atom with greater stability have less energy, so a reaction that the stability of the atom will release in the form of heat or light.
The condition of acidosis can also cause ____________ because the higher H concentration diffuses to the ICF, pushing K towards the ECF.
Answers
Answer:
Hyperkalemia
Explanation:
The condition of acidosis can also cause Hyperkalemia because the higher H concentration diffuses to the ICF, pushing K towards the ECF.
Consider the van deemter equation. why does increasing the flow rate reduce the contribution of longitudinal diffusion to total plate height?
Answers
Answer:
Why does increasing the flow rate reduce the contribution of longitudinal diffusion to total plate height? Increasing the flow rate decreases the time the solute resides in the column, resulting in less diffusional broadening.
Explanation:
4. If 100.0 g of water is cooled from 25.3°C to 16.9°C, what quantity of
energy has been transferred from the water?
Answers
Answer:
Dived the numbers by each other
Explanation:
25.3/19.9
what element generally appears in the formula of an acid
Answers
Answer:
Hydrogen, hope this helps :)
The web site of the Nobel Prize explains that readers who want to inspect the Curies' notebooks must sign a paper
that states that they are aware of the health risks that are involved with handling the notebooks. What health risk is
most likely to occur from handling the notebooks?
O excessive coughing
o anemia
O muscle cramping
O swelling of the joints
Answers
Answer: anemia because Marie curie died of anemia
why do solids maintain their shape whereas fluids do not
Answers
Suppose you have samples of three unknown solids. Explain how you could use their properties to determine whether or not they are ionic solids.
Answers
Given a sample of three unknown solids, we would be able to deduce which are ionic solids by their melting and boiling points, conductivity in water, and the insulation they provide.
What are Ionic solids?An ionic solid is a solid formed by ionic bonds. They are the solid version of ionic compounds, which are held together by strong electrostatic energies. What properties do they possess?Among their many properties, ionic solids possess high melting and boiling points.These solids are also known to conduct electricity well when dissolved into water, however, this can be tested after melting them as they will not conduct electricity in a solid state.A final property that we can use to identify them is that they provide a good means of insulation.Each of these properties can be tested and will allow us to determine the ionic solids amongst the samples.Therefore, we can find the ionic solids amongst the samples by testing their melting and boiling points, conductivity in water, and the insulation they provide, given that each of these should provide high values to indicate an ionic solid.
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Could someone help me with this?
Answers
Solving part-1 only
#1
KMnO_4
Transition metal is Manganese (Mn)#2
Actually it's the oxidation number of Mn
Let's find how?
[tex]\\ \tt\Rrightarrow x+1+4(-2)=0[/tex]
[tex]\\ \tt\Rrightarrow x+1-8=0[/tex]
[tex]\\ \tt\Rrightarrow x-7=0[/tex]
[tex]\\ \tt\Rrightarrow x=+7[/tex]
x is the oxidation number#3
Purple as per the color of potassium permanganate#4
[tex]\boxed{\begin{array}{c|c|c}\boxed{\bf Tube} &\boxed{\bf Charge} &\boxed{\bf No\:of\; electrons\: loss}\\ \sf 2 &\sf +6 &\sf 6e^-\\ \sf 3& \sf +2 &\sf 2e- \\ \sf 4 &\sf 4 &\sf 4e^-\end{array}}[/tex]
Minerals are _______ substances with a fixed crystal structure and a unique chemical composition. Processing ore sometimes involves _______ or grinding minerals. Prehistoric people used _______ for knives and arrowheads. The average American house contains about _______ pounds of minerals. Early _______ used rocks as simple tools as early as 2. 6 million years ago.
Answers
Minerals are solid substances with a fixed crystal structure and a unique chemical composition. Processing ore sometimes involves crushing or grinding minerals. Prehistoric people used flints for knives and arrowheads. The average American house contains about 250,000 pounds of minerals. Early Human culture used rocks as simple tools as early as 2. 6 million years ago.
What are minerals?Minerals are solid substances and are characterized by a fixed crystal structure and a unique chemical composition.
Early hominids used rocks as simple tools before the advent of modern civilization where other materials were used.
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Answer:
1. naturally occurring
2. crushing
3. flint
4. 250,000
5. hominids
A sample of Ammonia gas at 650mmHg and 15 degree has a mass of 56.8g.calculate the volume occupied by the gas. Take N=14, H=1,R=8.3145jk.
Answers
Answer:
The first thing we have to do is change and state all the units so that we can use our ideal gas law equation ([tex]PV = nRT[/tex]).
650 mmHg is a pressure unit, we have to convert this to kiloPascals. We know that 760 mmHg gives us 101 kPa.
[tex]650 \ mmHg \ * \ \frac{101kPa}{760 mmHg} = 86 \ kPa[/tex]
P = 86kPa
T = 15°C + 273K = 288K
R (Gas constant) = 8.31 kj/mol
Molar mass of Ammonia ([tex]NH_{3}[/tex]) = (1 x 3) + (14) = 17g/mol
n (moles) = [tex]\frac{mass}{molar \ mass}[/tex] [tex]= \frac{56.8}{17} =[/tex] 3.34 mol
V = ?
Rearrange the equation to solve for Volume:
[tex]V = \frac{nRT}{P}[/tex]
Substitute the values inside:
V = [tex]\frac{(3.34)(8.31)(288)}{(86)} = 93 L (rounded)[/tex]
Therefore 93 L of volume is occupied by the ammonia gas.
Describe a method you could use to carry out paper chromatography.
Answers
paper chromatography, in analytical chemistry, technique for separating dissolved chemical substances by taking advantage of their different rates of migration across sheets of paper..The method consists of applying the test solution or sample as a spot near one corner of a sheet of filter paper.
[tex]\large\sf\red{♡♡}[/tex]
Which statement describes one feature of Rutherford model of the atom
Answers
[tex] \huge{ \color{magenta}{ \fcolorbox{magenta}{black}{ \huge{ \color{white}{ \fcolorbox{aqua}{black}{♡Answer♡ }}}}}}[/tex]
The Rutherford model shows that an atom is mostly empty space, with electrons orbiting a fixed, positively charged nucleus in set, predictable paths.
If I remove the table from under the book, what will happen to the book? Think about Newton’s second law of motion. Is there an acceleration? What caused the acceleration?
Answers
Newton’s second law of motion is a dot product of mass and acceleration, if you remove the table from, under the book, gravity will act on the book and pull it downwards to the centre of the earth
Newton's Second law of motion states that "the acceleration of an object depends upon two variables – the net force acting on the object and the mass of the object."
In our case the mass of the book and the force of gravity
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PLEASE PEOPLE I NEED HELP PLEASE IF YOU SEE THIS HELP ME ! :,( !!!!! PLEASEEEEEEEEE
PLEASE NO LINKSSS !!!!! HELP ME THIS ITS FOR HOMEWORK PLEASE HELPP!
Answers
Answer:
year 1 is 5.5%
year 2 is 7.5%
year 3 is 10.2%
Explanation:
since,
length of the transect covered in seaweed / total lenth of transect x 100
then,
0.55 / 10.0 x 100 = 5.5
and
0.75 / 10.0 x 100 = 7.5
and
1.02 / 10.0 x 100 = 10.2
you could also just move the decimal to the right once
:)
PLEASE HELP QUICK I NEED 14-16 (JUST 6 PROBLEMS) ANSWERED AND FULL WORK SHOWN FOR FACTOR LABEL METHOD ITS 100 POINTS AND I WILL MARK BRAINLYEST.
Answers
Answer:
14. 21.51 liters
15. 12.9 centimeters
16. 3400 milliliters
Explanation:
I don't really know how to show the work
what is the difference between hydrophilic and hydrophobic?
Answers
Hydrophobic - resists water