Some building materials contain small capsules filled with paraffin wax to improve the insulating properties of the materials. The melting and freezing of paraffin inside the capsules in the material helps to regulate temperature. Paraffin wax begins to melt at 37°C37°C.(a) While the wax is melting, is the net flow of thermal energy from the wax to the surroundings or from the surroundings to the wax? Justify your answer.(b) Calculate the amount of thermal energy, in kJkJ, that is required to melt 15.215.2 grams of solid paraffin wax when the temperature of the surroundings is above the melting point of paraffin. (The molar mass of paraffin is 282.62g/mol282.62g/mol, and its molar heat of fusion is 48.78kJ/mol)(c) When paraffin wax melts, its density decreases. Provide a particle-level explanation of this observation.
Answers
Answer:
(a)
From surrounding to wax
(b)
Q = 2.62 KJ
(c)
Density of a substance is defined as the no. of particles of the substance, that occur in a unit volume. So, when the substance melts, the inter-molecular attractive forces and bonds between molecules or atoms are weakened. This, increases the distance between the molecules or atoms. Hence, the no. of particles in a unit volume is decreased. As, a result of this, the density of the substance also decreases.
Explanation:
(a)
During the melting process, the solid material or substance requires energy, in order to break the bonds between its molecules or atoms.
Therefore, while the wax is melting, the net flow of thermal energy is from surrounding to the wax.
(b)
The amount of energy required to melt solid paraffin wax is given by the formula:
Q = nC
where,
Q = amount of energy
C = Molar Heat of Fusion = 48.78 KJ/mol
n = No. of Moles = Mass in gram/Molar Mass = (15.2 g)/(282.62 g/mol)
n = 0.0538 mol
Therefore,
Q = (0.0538 mol)(48.78 KJ/mol)
Q = 2.62 KJ
(c)
Density of a substance is defined as the no. of particles of the substance, that occur in a unit volume. So, when the substance melts, the inter-molecular attractive forces and bonds between molecules or atoms are weakened. This, increases the distance between the molecules or atoms. Hence, the no. of particles in a unit volume is decreased. As, a result of this, the density of the substance also decreases.
(a) During the melting of wax, the flow of thermal energy has been from the surroundings to the wax.
(b) The amount of heat requires for the melting of 15.215 grams of solid paraffin has been 2.62 kJ.
(c) The density decreases due to a decrease in the number of molecules per unit volume.
(a) Melting results in the conversion of solid-state to the liquid state. This step requires energy. Thus, the flow of energy has been from the surroundings to the wax.
(b) Amount of heat requires (Q) can be given by:
Q = nC
Where, n = moles of the sample, and C = heat of fusion
Moles of paraffin = \(\rm \dfrac{weight}{molecular\;weight}\)
Moles of paraffin = \(\rm \dfrac{15.215}{286.62}\)
Moles of paraffin = 0.0538 moles
Q = 0.0538 \(\times\) 48.78 kJ/mol
Q = 2.62 kJ.
The amount of heat requires for the melting of 15.215 grams of solid paraffin has been 2.62 kJ.
(c) The density has been the mass or number of particles present per unit volume. The melting of wax results in a weaker intermolecular force. The resulting liquid will have fewer molecules present in the unit volume.
Thus, the density decreases due to a decrease in the number of molecules per unit volume.
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Related Questions
name the hydrocarbon ch3ch2l
Answers
The given hydrocarbon CH₃CH₂I is ethyl iodide or iodoethane. It is a colourless flammable chemical compound which is produced by heating ethanol with iodine and phosphorous.
What is hydrocarbon?The organic compounds which is composed of only carbon and hydrogen atoms are known as hydrocarbons. Methane, ethane, propane, etc. are some examples of hydrocarbon.
Here iodoethane is a saturated hydrocarbon. The hydrocarbons in which the 'C' and 'H' atoms are bonded through single bonds are called saturated hydrocarbons. In unsaturated hydrocarbons 'C' and 'H' atoms are connected through double or triple bonds.
Alkanes belongs to the class of saturated hydrocarbons whereas Alkenes and Alkynes are unsaturated hydrocarbons. The ability of hydrocarbons to bond themselves is defined as the catenation.
The expanded structural formula of iodoethane is CH₃ - CH₂ - I . The formula of each hydrocarbons will be different from one another.
Thus the name of CH₃CH₂I is ethyl iodide or iodoethane.
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WILL GIVE BRAINLIST
3) In the food chain below, Which level has the least amount of energy?
E)Herbivore
A) Secondary Consumer
O) Producer
4) Which of the following is an ecosystem?
M) A moose
I) The biotic factors in the rainforest
B) A corn Field
I thinks it A and I
Answers
Explanation:
it's probably gonna be the secondary consumer, energy is lost/reduced as it goes up the food chain
(2) A corn field is an ecosystem, in it, you'll find the interaction of both animals, insects, microorganisms and plants in it
Vinegar is sold at the grocery store with a concentration of 5.0 % acetic acid. How many grams of acetic acid are in 28 g of Vinegar?
Answers
White vinegar typically consists of 93%–96% water and 4–7% acetic acid. It can be used to cooking, bake, cleaning, and get rid of weeds. It can also help you lose weight and lower your blood sugar and cholesterol. Consumption is safe in moderation, but excessive consumption or when combined with certain medications could be harmful.
Apple cider vinegar is widely used in cooking and as a salad dressing because it contains acetic acid and nutrients like vitamins C and B vitamins. But at the same time, it's been utilized customarily as medication. It helps in losing weight.
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Use the data in the Successive Ionization Energies and Electron Affinity tables to determine the following. (Assume the values in the Successive Ionization Energies table are given to the ones place.) (a) the electron affinity of Ar2+ kJ/mol (b) the electron affinity of Si + kJ/mol (c) the ionization energy of Cl − kJ/mol (d) the ionization energy of Cl kJ/mol (e) the electron affinity of Cl + kJ/mol
Answers
Answer:
Use the data in the Successive Ionization Energies and Electron Affinity tables to determine the following. (Assume the values in the Successive Ionization Energies table are given to the ones place.)
(a)
the electron affinity of Ar2+
kJ/mol
(b)
the electron affinity of S+
kJ/mol
(c)
the ionization energy of Cl−
kJ/mol
(d)
the ionization energy of Cl
kJ/mol
(e)
the electron affinity of Cl+
kJ/mol
Successive Ionization Energies in Kilojoules per Mole for the Elements in Period 3 General increase 13 14 Element 11 12 I. 16
Explanation:
how to get ice and snow
power?
Answers
Answer:
i don't think you can, but if you do know let me know
Two compounds of phosphorus and flurorine have the following mass ratios
Compound 1: 10.14 g fluorine for every 3.38 g phosphorus
Compound 2: 8.42 g flurorine for every 4.21 g phosphorus
Find the whole number ratio of masses of flurorine in compound 1 to compound 2
Answers
Answer:
25.6 Explanation:
What is a cell? ♀️
Answers
Answer:
Cell is defined as the smallest unit or basic unit of life.
the smallest part of a living thing that can carry out the activities needed for life. Basically the unit of all forms of life.
Explanation:
hope this helps in anyway :)
In the SOLID state of matter ,particles have enough energy to move freely but not enough energy to overcome their attraction for each other
Answers
In the solid state of matter, particles, such as atoms, ions, or molecules, are closely packed and held together by strong intermolecular forces, such as ionic bonds, metallic bonds, or covalent bonds.
In a solid, particles have enough energy to vibrate around fixed positions but do not have enough energy to overcome the attractive forces between them. These attractive forces, also known as cohesive forces, arise from the electrostatic interactions between particles or the sharing of electrons in covalent bonds.
The energy of the particles in a solid is typically much lower than in the liquid or gaseous states, resulting in a fixed arrangement of particles.
The movement of particles in a solid is characterized by vibrations or oscillations around their equilibrium positions.
These vibrations occur due to the thermal energy present in the solid, but the particles remain relatively fixed in their positions due to the strong attractive forces. The amplitude of the vibrations increases with increasing temperature, as the particles gain more thermal energy.
However, the particles in a solid do not have enough energy to break the intermolecular bonds and move freely throughout the entire solid. Instead, they can only move within their local vicinity or lattice positions.
This restricted movement is what distinguishes the solid state from the liquid or gaseous states, where particles have enough energy to overcome intermolecular forces and move more freely.
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3.7 x 10^24 carbon atoms, how many moles of carbon do you have?
Answers
Answer:
6.15 moles
Explanation:
1 mole of C has 6.02 x 10^23 atoms
the number of mole in 3.7 x 10^24 is
(1 mole)(3.7 x 10^24)/(6.02 x 10^23)
= 6.15 moles
Describing Dilutions
Which methods could be used to dilute a solution of sodium chloride (NaCl)? Select all that apply.
Add more NaCl to the solution.
Add more water to the solution.
Remove a small amount of the solution and mix it with water.
Heat the solution to evaporate some of the water.
Answers
To dilute a solution of sodium chloride (NaCl), we can use the following methods: Add more water to the solution and Remove a small amount of the solution and mix it with water.
By adding water, you increase the overall volume of the solution, which effectively reduces the concentration of NaCl. This is the most common and straightforward method of dilution.
By taking out a portion of the concentrated solution and mixing it with water, you decrease the concentration of NaCl in that portion, resulting in overall dilution when you combine it back with the rest of the solution.
By heating the solution, you cause the water to evaporate, leaving behind a more concentrated solution of NaCl. This process does not dilute the solution but rather concentrates it further.
Adding more NaCl to the solution would actually increase the concentration, not dilute it. Therefore, it is not a valid method for dilution.
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what do we call the cammell their
Answers
Answer:
You have to write the full question
How many main groups of elements are there
Answers
Answer:
The s-, p-, and d-block elements of the periodic table are arranged into 18 numbered columns, or groups. The elements in each group have the same number of valence electrons. As a result, elements in the same group often display similar properties and reactivity.
Explanation:
The Sun has been shining on this swimming pool all day. The water is much warmer than it was in the morning. Describe what is happening to the water in terms of temperature, particle speed, and kinetic energy.
Answers
Answer:
The waters' temp increased
Explanation:
The temperature of the water in the swimming pool has increased due to the heat from the Sun. As a result, the particles in the water are moving faster and have a higher kinetic energy than in the morning.
When 7.524 is rounded to 3 sig figs it will be
Answers
When 7.524 is rounded to 3 significant figures, it will be 7.52.
The process of changing a number to a nearby number with fewer significant digits is known as rounding.
Rounding can be done to the nearest integer, the nearest tenth, the nearest hundredth, and so on.
Here are some pointers on rounding numbers to a certain number of significant digits:If the digit following the last significant digit is less than 5, simply drop it and all following digits.
(round down)For example, 2.832 rounded to two significant digits is 2.8 since the 3 is followed by a 2 which is less than 5.
If the digit following the last significant digit is greater than 5, add 1 to the last significant digit, then drop all of the digits that follow it.
(round up)For example, 4.673 rounded to two significant digits is 4.7 since the 3 is followed by a 7 which is greater than 5.
If the digit following the last significant digit is exactly 5, the preceding digit is odd, and no other digits follow, increase the last significant digit by 1.
If the digit following the last significant digit is exactly 5, the preceding digit is even, and no other digits follow, simply leave the last significant digit alone.
For example, 2.875 rounded to two significant digits is 2.9 since the 5 is followed by an odd number, which means that the 8 should be rounded up, while 2.765 rounded to two significant digits is 2.8 since the 5 is followed by an even number, which means that the 6 should be left alone.
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HELLLLPPP PLEASEEEEE, Light travels through some materials, but not others. The table shown organizes materials under three headings: transparent, translucent, and opaque.
Transparent: window, ice cube, lens.
Translucent: air, wax paper, jelly fish
Opaque: wood, mirror, water
Which materials are listed under the wrong heading?
Answers
Answer:
hello lets talk here
Explanation:
Answer:
Ice Cube, Water, and Air
Explanation:
An Ice cube is cloudy so you can't exactly see through it. It's Opaque.
You can't look through water clearly. It's Translucent.
You can see straight through air. It's Transparent.
Hope this helps. Have a nice day you amazing bean child
When Chlorine gas is put in contact with Aluminum metal at high temperatures, Aluminum Chloride is produced. word equation and balanced
Answers
The balanced chemical equation when chlorine gas is put in contact with aluminium metal at high temperatures to form aluminium chloride is 2 Al + 3 Cl₂\(\rightarrow\) 2 AlCl₃.
What is chemical equation?Chemical equation is a symbolic representation of a chemical reaction which is written in the form of symbols and chemical formulas.The reactants are present on the left hand side while the products are present on the right hand side.
A plus sign is present between reactants and products if they are more than one in any case and an arrow is present pointing towards the product side which indicates the direction of the reaction .There are coefficients present next to the chemical symbols and formulas .
The first chemical equation was put forth by Jean Beguin in 1615.By making use of chemical equations the direction of reaction ,state of reactants and products can be stated. In the chemical equations even the temperature to be maintained and catalyst can be mentioned.
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What is the charge on the Co ions in Co2O3?
Answers
Answer:
6-
Explanation:
the total oxide ion charge in the formula unit is 6-
Answer:
The answer is 6-
Explanation:
correct :)
Polar water molecules can surround ions, reducing the likelihood of them interacting with other ions. What property of water does this phenomenon cause?
Answers
The property of water that causes polar water molecules to surround ions, reducing the likelihood of them interacting with other ions, is known as its solvation or hydration ability.
This solvation property is a result of water's high polarity, which arises from its asymmetrical molecular structure and the presence of polar covalent bonds. Water molecules have a partially positive (+) and partially negative (-) end due to the electronegativity difference between oxygen and hydrogen atoms. This polarity enables water molecules to form hydrogen bonds with other water molecules and with polar solutes, such as ions. When ions dissolve in water, the partially positive hydrogen atoms of water molecules are attracted to the negatively charged ions, and the partially negative oxygen atoms of water molecules are attracted to the positively charged ions.
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The irreversible isomerization A
B was carried out in a batch reactor and the following concentration time data were obtained:
Time vs Concentration data in a Batch reactor
t 0 3 5 8 10 12 15 7.5
mol/h 4 2.89 2.25 1.45 1.0 0.65 0.25 0.07
Determine the reaction order,
, and the specific reaction a rate constant, k, using any method of your choice.
Answers
The reaction order and specific reaction rate constant can be determined by performing the kinetics experiment on irreversible polymerization A. Kinetic experiments can be used to investigate the rate and mechanism of chemical reactions. Chemical kinetics is the study of chemical reactions' speed and pathway.
The term "kinetics" refers to the study of reaction rates, which are determined by measuring the concentration of reactants and products as a function of time.Kinetics experiments can be used to determine the reaction rate and order of reaction. A chemical reaction's rate is defined as the change in the concentration of a reactant or product per unit time. The order of a reaction refers to the number of molecules that must react to produce a product. The order of reaction can be determined by measuring the initial rate of the reaction as a function of concentration.Methods for determining the reaction rate order include the initial rate method, the half-life method, and the integrated rate method. The initial rate method determines the reaction order by measuring the initial rate of the reaction at different reactant concentrations. The half-life method determines the reaction order by measuring the time it takes for the reactant concentration to decrease by half.The integrated rate method determines the reaction order by measuring the concentration of the reactant or product at different times.The specific rate constant can be determined by using the Arrhenius equation, which relates the rate constant to the activation energy, temperature, and frequency factor. The frequency factor can be determined by measuring the rate constant at different temperatures.For such more question on polymerization
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The total number of atoms in 3Na2O?
Answers
Answer:
5 atoms
Explanation:
3 sodium
2 oxygen
You are making sweet tea. You add 56 g of sugar into 78 g of tea. What is the
mass percent of sugar?*
79%
42%
72%
ОО
56%
Answers
Answer:
\(\%Mass =42\%\)
Explanation:
Given
Sugar = 56g
Tea = 78g
Required
Determine the mass percent of the sugar
First we need to calculate the total mass
\(Total\ Mass = Sugar + Tea\)
\(Total\ Mass = 56g + 78g\)
\(Total\ Mass = 134g\)
The percentage mass is then calculated as thus
\(\% Mass = \frac{Sugar}{Total\ Mass} * 100\%\)
Substitute 56 and 134 for Sugar and Total mass respectively
\(\% Mass = \frac{56}{134} * 100\%\)
\(\%Mass =0.41791044776 * 100\%\)
\(\%Mass =41.791044776\%\)
Approximate
\(\%Mass =42\%\)
Hence, the percentage mass of sugar is 42%
A group of tissues that work together to perform a specific function is called
a. a cell
b. an organ
c. a system
d. an organism
Answers
Answer:
B. Organ.
Explanation:
College Biology Major here.
Khpo4 is mono basic salt but when I write potassium phosphate mono basic then I get kh2po4
Answers
It is a salt formed from the potassium cation (K+) and the phosphate anion (H2PO4-). This salt is considered monobasic because it contains one replaceable hydrogen ion (H+).
KH2PO4 is actually potassium dihydrogen phosphate, not potassium phosphate monobasic. Potassium phosphate monobasic, or monopotassium phosphate, is correctly represented by the chemical formula KH2PO4. It is a salt formed from the potassium cation (K+) and the phosphate anion (H2PO4-). This salt is considered monobasic because it contains one replaceable hydrogen ion (H+).
On the other hand, potassium dihydrogen phosphate, or K2HPO4, is a different compound. It is formed from the potassium cation (K+) and the hydrogen phosphate anion (HPO4^2-). This compound is considered dibasic because it contains two replaceable hydrogen ions (H+).
Therefore, KH2PO4 is correctly identified as potassium phosphate monobasic, while K2HPO4 is potassium dihydrogen phosphate.
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(NH4)3PO4 + CaBr2 = Ca3(PO4)2 + NH4Br
ionic equation
Answers
Answer:
2(NH4)3PO4 + 3CaBr2 → Ca3(PO4)2 + 6NH4Br
Explanation:
Tribasic Ammonium Phosphate + Calcium Bromide = Tricalcium Phosphate + Ammonium Bromide
Reaction Type
Double Displacement (Metathesis)
Reactants
Tribasic Ammonium Phosphate - (NH4)3PO4
Ammonium Phosphate
Molar Mass of H12N3O4P Oxidation State of H12N3O4P
Calcium Bromide - CaBr2
Kalziumbromid CaBr2 Calcium Bromide Hydrate
Molar Mass of Br2Ca Oxidation State of Br2Ca
Products
Tricalcium Phosphate - Ca3(PO4)2
Bone Phosphate Of Lime BCP TCP Tricalcium Orthophosphate Calcium Phosphate Tertiary Calcium Phosphate Calcium Orthophosphate Ca3(PO4)2
Molar Mass of Ca3O8P2 Oxidation State of Ca3O8P2
Ammonium Bromide - NH4Br
NH4Br
Molar Mass of BrH4N Oxidation State of BrH4N
function of carpel pls help meeee
Answers
Nitrogen gas reacts with hydrogen gas to produce ammonia. How many liters of hydrogen gas at 95kPa and 15∘C are required to produce 100 g of ammonia
Answers
Answer:
222.30 L
Explanation:
We'll begin by calculating the number of mole in 100 g of ammonia (NH₃). This can be obtained as follow:
Mass of NH₃ = 100 g
Molar mass of NH₃ = 14 + (3×1)
= 14 + 3
= 17 g/mol
Mole of NH₃ =?
Mole = mass /molar mass
Mole of NH₃ = 100 / 17
Mole of NH₃ = 5.88 moles
Next, we shall determine the number of mole of Hydrogen needed to produce 5.88 moles of NH₃. This can be obtained as follow:
N₂ + 3H₂ —> 2NH₃
From the balanced equation above,
3 moles of H₂ reacted to produce 2 moles NH₃.
Therefore, Xmol of H₂ is required to p 5.88 moles of NH₃ i.e
Xmol of H₂ = (3 × 5.88)/2
Xmol of H₂ = 8.82 moles
Finally, we shall determine the volume (in litre) of Hydrogen needed to produce 100 g (i.e 5.88 moles) of NH₃. This can be obtained as follow:
Pressure (P) = 95 KPa
Temperature (T) = 15 °C = 15 + 273 = 288 K
Number of mole of H₂ (n) = 8.82 moles
Gas constant (R) = 8.314 KPa.L/Kmol
Volume (V) =?
PV = nRT
95 × V = 8.82 × 8.314 × 288
95 × V = 21118.89024
Divide both side by 95
V = 21118.89024 / 95
V = 222.30 L
Thus the volume of Hydrogen needed for the reaction is 222.30 L
mention one metal that doesn't burn or form oxide when heated in air
Answers
Answer:
Gold, Platinum, Silver, Ruthenium
How to get nail polish remover off the top of your chrome book
Answers
Answer:
Explanation: I saw that you answered someone else's same question with toothpaste. What toothpaste did you use?
A student performed an experiment in which 10 mL of a strong acid was placed on a sample of limestone. Bubbles formed where the acid touched the limestone. After 20 minutes, the bubbling stopped and the surface of the limestone appeared unchanged. What is an observation that suggests a chemical reaction did in fact take place between the acid and the limestone?
a) The limestone appeared to be unchanged.
b) The acid had to be prepared beforehand.
c) Bubbles formed where the acid and limestone touched.
d) None of the above
Answers
Answer:
Answer is D, None of the above :)
Explanation:
pOH of the 0.001M NaOH solution is
Answers
The pOH of the 0.001 M NaOH solution is approximately 3.
To determine the pOH of a solution, we need to know the concentration of hydroxide ions (OH-) in the solution.
In the case of a 0.001 M NaOH solution, we can assume that all of the NaOH dissociates completely in water to form Na+ and OH- ions. Therefore, the concentration of hydroxide ions in the solution is also 0.001 M.
The pOH is calculated using the equation:
pOH = -log[OH-]
Substituting the concentration of hydroxide ions, we have:
pOH = -log(0.001)
Using a calculator, we can evaluate the logarithm:
pOH ≈ 3
Therefore, the pOH of the 0.001 M NaOH solution is approximately 3.
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