isabellaludlow101 avatar isabellaludlow101 09/28/2022 Chemistry College answered • expert verified Forensic scientist Samantha Monzon is collecting physical evidence at a crime scene where someone was murdered. What does this process MOST likely involve? A. She will place all items in an airtight, plastic container. B. She will have to leave weapons such as guns and knives at the scene. C. She will need to obtain a search warrant before she collects anything. D. She will collect anything that could be related to the crime.
Answers
The process of collecting physical evidence at a crime scene by forensic scientist Samantha Monzon would most likely involve: (D) She will collect anything that could be related to the crime.
Forensic scientists are trained to collect and preserve any potential evidence that could be relevant to the crime under investigation. This includes items such as weapons, personal belongings, biological samples, fingerprints, fibers, and any other potential traces left behind at the crime scene. The goal is to gather as much evidence as possible to aid in the investigation and provide a comprehensive analysis of the crime.
Regarding the other options:
A. While it is common for evidence to be stored in appropriate containers, the specific choice of an airtight, plastic container would depend on the nature of the evidence.
B. Weapons such as guns and knives would typically be collected as evidence, rather than being left at the scene.
C. While search warrants may be required in certain situations, the act of collecting physical evidence at a crime scene does not necessarily involve obtaining a search warrant.
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Related Questions
what are cells
1. the smallest things that can carry out life processes
2. parts of a molecule
3. parts of an atom
Answers
1.the smallest things that can carry out life proccess
. What is the percentage error for a mass measurement of 17.7 g, given that the correct value is 21.2 g?
Answers
Answer: 16.5% First, determine the total error by subtracting the accepted value from the value you measured. e = 17.7 -21.2 = -3.5 Then
divide the error
Explanation:
an interpenetrating primitive cubic structure like that of cscl with anions in the corners has an edge length of 322 pm. the anions are at the corners of the unit cell, and the ratio of the ionic radius of the cation to the ionic radius of the anion is 0.850. what is the ionic radius of the anion (in picometers)?
Answers
The cation radius is: 161 pm
and the ionic radius of the anion (in picometers) is: 189.41 picometers
Given an edge length of 322 pm and a ratio of 0.850 between the ionic radius of the cation and the ionic radius of the anion. This can be done using a combination of geometry and the given information. The edge length of a primitive cubic structure like that of cscl is twice the distance between two adjacent anions.
Therefore, if the edge length is 322 pm, the distance between two anions is 161 pm. Since the ratio of the ionic radius of the cation to the ionic radius of the anion is 0.850, we can use this formula to calculate the ionic radius of the anion
Anion Radius = Cation Radius / 0.850
If the cation radius is 161 pm, the anion radius is 189.41 pm or 189.41 picometers.
In summary, given an edge length of 322 pm and a ratio of 0.850 between the ionic radius of the cation and the ionic radius of the anion, we can calculate the ionic radius of the anion by first finding the distance between two adjacent anions, which is half of the edge length, then dividing the cation radius by the given ratio.
In this case, the cation radius is 161 pm and the anion radius is 189.41 pm or 189.41 picometers.
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Does Fe(NO3)2 react with Pb
Answers
Answer:you only need one to balance Fe(NO3)2 react with Pb
Explanation:
what type of reaction is performed with the elephant toothpaste demonstration?
Answers
The reaction performed with the elephant toothpaste demonstration is known as a decomposition reaction.
Decomposition Reaction:The process of breaking down a chemical compound into smaller molecules, atoms, or ions is known as a decomposition reaction. It is also known as analysis or disintegration. A reaction in which a single substance is broken down into two or more simpler substances is known as a decomposition reaction. The elephant toothpaste demonstration is a simple chemical reaction in which hydrogen peroxide breaks down into oxygen gas and water in a matter of seconds.
The formula for hydrogen peroxide is H₂O₂. It is a pale blue liquid that contains hydrogen, oxygen, and water. When you add yeast, soap, and food coloring, the reaction is more exciting. The yeast acts as a catalyst, breaking down hydrogen peroxide into water and oxygen gas. The oxygen gas created causes the soap to foam up, creating the "elephant toothpaste" effect. The chemical reaction that takes place during the elephant toothpaste demonstration can be written as follows:
2H₂O₂(liquid) → 2H₂O (liquid) + O₂ (gas)
This reaction is an example of a decomposition reaction.
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GIYS PLEASE HELP ME YURR PLEASE PLEASE
Answers
Answer: i dont think anyone know because its ghard
Explanation:
what is the total volume of gaseous products formed when 38.4 liters of butane () react completely according to the following reaction? (all gases are at the same temperature and pressure.)
Answers
The total volume of gaseous products formed is 799.68 L.
The reaction is given as :
2C₄H₁₀(g) + 13O₂(g) ----> 8CO₂(g) + 10H₂O(g)
22.4 L volume is occupied = 1 mol
38.4 L volume is occupied = (1 / 22.4 ) × 38.4
= 1.7 mol
2 moles of C₄H₁₀ = 8 moles CO₂
1.7 mol of C₄H₁₀ = (8 / 2) 1.7
= 27.2 mol CO₂
volume of CO₂ at STP = 27.2 × 22.4
= 609.28 L
2 moles of C₄H₁₀ = 10 moles of H₂O
1.7 mol of C₄H₁₀ = ( 10 / 2) 1.7
= 8.5 mol of H₂O
volume of H₂O = 8.5 × 22.4
= 190.4 L
total volume of gaseous product = 609.28 + 190.4 = 799.68 L
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suppose you added 4.000 g of fp sample 1 instead of 2.000 g, what would happen to the freezing point temperature of the water?
Answers
If 4.000 g of sample 1 were added to the water instead of 2.000 g, the freezing point depression of the water would increase.
Freezing point depression is a phenomenon that occurs when a solute is dissolved in a solvent, such as water. The presence of solute molecules in the solvent interferes with the formation of ice crystals, causing the solution's freezing point to decrease. The magnitude of the freezing point depression is directly proportional to the concentration of solute in the solution. This means that if the amount of solute increases, the freezing point depression will also increase. If adding 4.000 g of sample 1 instead of 2.000 g, the concentration of the solute in the water will be higher, leading to a greater depression of the freezing point. This means that the water will freeze at a lower temperature than it would if only 2.000 g of sample 1 were present.
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If 4.000 g of sample 1 were added to the water instead of 2.000 g, the freezing point depression of the water would increase.
What do you mean by Freezing point depression ?Freezing point depression is a phenomenon that occurs when a solute is dissolved in a solvent, such as water. The presence of solute molecules in the solvent interferes with the formation of ice crystals, causing the solution's freezing point to decrease. The magnitude of the freezing point depression is directly proportional to the concentration of solute in the solution. This means that if the amount of solute increases, the freezing point depression will also increase. If adding 4.000 g of sample 1 instead of 2.000 g, the concentration of the solute in the water will be higher, leading to a greater depression of the freezing point. This means that the water will freeze at a lower temperature than it would if only 2.000 g of sample 1 were present.
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Which describes the dissolving process? (Choose all that Apply)
A) All molecules are in constant motion, so they run into each-other.
B) Molecules bond with the solvent forming a chemical reaction.
C) Collisions of molecules is what makes a substance dissolve
D) Molecules of the solvent bombard molecules of the solute.
Answers
Answer:
A and D
Explanation:
I took the test, and choose both B and C and got it wrong
you find 13406190 pennies. how many dollars did you actcually find? if each penny weighs 4 grams, how much does all of it weigh in ponds
Answers
Answer:
134,061.9 dollars and 118,222.45 lbs.
Explanation: you're welcome :)
at a certain concentration of h2 and nh3, the initial rate of reaction is 22.0 m / s. what would the initial rate of the reaction be if the concentration of h2 were halved? be sure your answer has the correct number of significant digits.
Answers
To find the correct number significant digits, learn the concentration and initial rate.
What is concentration?
In chemistry and related fields, the idea of concentration is used frequently. It is a way to gauge how much of one substance is incorporated into another.
What is initial rate?
When a reaction first begins, or when t = 0, its initial rate is the rate that exists at that precise moment. At time zero (t), the slope of the reactant concentration versus the time curve is equal to the initial rate.
Rak=k(H₂) (NH₃) Rak law expression
1. reaction order w.r.t H₂ is ⇒2
2. reaction order w.r.t NH₃ is⇒ 1.
3. overall order 2+1=3 ( bird order reaction)
4. k(H₂) (NH₃)= 0.740⇒ 1
H₂ is doubled ⇒ r₂=k(H₂) (NH₃)=4k(H₂) (NH₃)⇒2
(2)/(1) = r₂/r₁ = 4k(H₂) (NH₃)/k(H₂) (NH₃)=4
r₂= 4∝ r₁ = 4∝ 0.740=2.96m/s
5. r= 6.0∝ 10^⁴m/s, (H₂)= 0.98m, (NH₃)= 0.31m
r=k(H₂) (NH₃)
k=r/(H₂) (NH₃)= 6.0 ∝ 10^⁴/(0.98)^²(0.31)=201528.93m^⁻²s^⁻¹
K=2.0 ∝ 10^5m^⁻²s^⁻¹
Therefore, the significant digit is K=2.0 ∝ 10^5m^⁻²s^⁻¹
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is Sulfuric Acid soluble if placed in water
Answers
Answer: Yes, sulfuric acid is highly soluble in water.
Explanation:
Draw all possible lewis structures (including resonance structures for methyl azide (ch3n3 using lewis structure rules. One or more of your structures may seem unstable or unlikely; include them in your answer as long as they do not violate lewis structure rules. For each resonance structure, assign formal charges to all atoms that have formal charge. Draw all possible lewis dot structure for methyl azide. Include all hydrogen atoms and nonbonding electrons. Show the formal charges of all atoms
Answers
Structure 1:
H
|
H - C = N
|
N
|
N
Structure 2:
H
|
H - C ≡ N
|
N
|
N
Structure 3:
H
|
H - C ≡ N+
|
N-
|
N
In Structure 1, there is a double bond between the central carbon atom and one of the nitrogen atoms, and a single bond between the central carbon atom and the other nitrogen atom. In Structure 2, there is a triple bond between the central carbon atom and one of the nitrogen atoms, and a single bond between the central carbon atom and the other nitrogen atom. In Structure 3, there is a triple bond between the central carbon atom and the positively charged nitrogen atom, and a single bond between the central carbon atom and the negatively charged nitrogen atom.
All three structures satisfy the octet rule for all atoms and obey the Lewis structure rules.
For resonance structures, we can observe that Structures 1 and 2 are actually resonance structures of each other, as the double and triple bonds can be interchanged without violating any valence electron rules. Therefore, we can draw a hybrid structure that represents the average of these two resonance structures:
Hybrid Structure:
H
|
H - C = N ⇌ H - C ≡ N
|
N
|
N
In this hybrid structure, the double and triple bonds have equal bond order and the formal charges on all atoms are as follows:
Carbon: 0
Nitrogen (single bond): 0
Nitrogen (double/triple bond): 0
Hydrogen: +1
Note that the formal charge on the carbon atom is zero in all structures, and the formal charges on the nitrogen and hydrogen atoms are all either zero or +1, which are the most stable formal charges for these atoms.
which of the following are not acids? ch3cooh co2 hno2 hcooh ccl4
Answers
CCl4 is the substance that is not acidic out of the given list.
Acids are chemical substances that, when dissolved in water, increase the number of hydrogen ions, H+, present. For a substance to be acidic, it must have a pH of less than 7. Acids have a sour taste, react with bases to form salts and water, and turn blue litmus paper red. They are used in food, medicine, cleaning products, and many other industries.
The following substance is not acidic: CCl4
Ch3COOH is acetic acid, CO2 is carbonic acid, HNO2 is nitrous acid, and HCOOH is formic acid. All of these substances dissolve in water and release H+ ions, making them acidic.
CCl4, on the other hand, is carbon tetrachloride. It is a nonpolar compound that is insoluble in water and does not release H+ ions. As a result, it is not acidic.
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What is the rate law for the reaction A → B if the rate constant, k, is 0.25 M⁻¹ s⁻¹ at 75°C?
a.) Rate = 0.25 M^-1 s^-1 [A]
b.) Rate = 0.25 M^-1 s^-1 [A]^2
c.) Rate = 4.0 M^-1 s^-1 [A]^2
d.) Rate = 0.25 M^-1 s^-1 [B]
e.) Rate = 0.25 M^-1 s^-1 [B]^2
Answers
In the given query, the rate law for the reaction: \(\rm A \rightarrow B\) if the rate constant, k, is 0.25 M⁻¹ s⁻¹ at 75°C is Rate = \(\rm 0.25\ M^{-1} s^{-1 }[A]^2\). Option b is the correct answer.
The rate law is an equation that depicts how the rate of a chemical reaction depends on the concentrations of the reactants.
Given: \(\rm A \rightarrow B\)
k= 0.25 M⁻¹ s⁻¹ at 75°C
Based on the rate constant, the given reaction is second order reaction. The rate law can be written as:
\(\rm Rate \propto k[A]^ 2\)
Where k is the rate constant and [A] is the concentration of A.
\(\rm Rate = k[A]^ 2\)
Putting the value of k in the above equation, we get:
\(\rm Rate= 0.25 M^{-1} s^{-1} [A]^ 2\)
Therefore, Option b. "Rate = \(\rm 0.25\ M^{-1} s^{-1 }[A]^2\)" is the correct choice.
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What does the oxidation number for elements of first transition series range between ?
Answers
The range of the of the oxidation number of the first transition series is +2 to +6.
What is transition metal?
Transition elements or transition metals are elements or metals that have partially filled d orbitals.
Examples of first transition metalsThe first main transition series begins with either;
scandium (Sc, atomic number 21)titanium (Ti, atomic number 22) chromium (Cr, atomic number 24) and ends with zinc (Zn, atomic number 30)Range of oxidation number of transition metalsscandium - oxidation number = +3titanium - oxidation number = +2, +3, and +4Chromium - oxidation number = + 6zinc - oxidation number = +2Thus, the range of the of the oxidation number of the first transition series is +2 to +6.
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How many inner transition metals are there?
Answers
Answer: 28 inner transition elements
why is it necessary to indicate the state (s, i, g, aq) of products and reactants when writing a thermochemical equation?
Answers
In a thermochemical equation, the reactants' and products' physical states must be taken into account because they affect the value of H. In the course of an endothermic reaction, the environment provides energy.
What is Thermochemical Equations?The only difference between thermochemical equations and other balanced equations is that they also indicate the heat flow for the reaction. The equation's right side includes a list of the heat flow denoted by the letter H.Kilojoules, or kJ, are the most widely used units. Two thermochemical equations are provided here:H2 (g) + ½ O2 (g) → H2O (l); ΔH = -285.8 kJ
HgO (s) → Hg (l) + ½ O2 (g); ΔH = +90.7 kJ
The enthalpy of a substance depends upon temperature. Ideally, you should specify the temperature at which a reaction is carried out. When you look at a table of heats of formation, notice that the temperature of the ΔH is given. For homework problems, and unless otherwise specified, the temperature is assumed to be 25°C. In the real world, the temperature may be different and thermochemical calculations can be more difficult.A substance's enthalpy is temperature-dependent. The ideal situation would be to state the temperature at which a reaction occurs. Observe that the temperature of the H is mentioned in a table of formation temperatures. The temperature is assumed to be 25°C for homework problems unless otherwise stated. Calculations involving thermochemistry may be more challenging in the real world due to temperature variations.To Learn more about thermochemical equation refer to:
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which molecule has the strongest intermolecular forces?
A.) HOCH2CHOHCHOHCH2OH
B.) CH3CH2CH2OH
C.) HOCH2CH2CH2OH
D.) CH3CH2CH2CH3
Answers
The molecule with the strongest intermolecular forces is A) HOCH2CHOHCHOHCH2OH.
The strength of intermolecular forces depends on several factors, including molecular size, shape, and polarity.
In this case, A) HOCH2CHOHCHOHCH2OH (a diol with multiple hydroxyl groups) has the strongest intermolecular forces due to the presence of multiple hydrogen bonds. Hydrogen bonds are the strongest intermolecular forces and occur between molecules that have a hydrogen atom bonded to a highly electronegative atom (such as oxygen or nitrogen) and a lone pair of electrons on a neighboring molecule.
B) CH3CH2CH2OH (a primary alcohol) has weaker intermolecular forces than A because it only has one hydroxyl group and can only form one hydrogen bond.
C) HOCH2CH2CH2OH (a primary alcohol) has a similar number of hydroxyl groups as B but is slightly larger, allowing for more opportunities for hydrogen bonding.
D) CH3CH2CH2CH3 (a simple alkane) has the weakest intermolecular forces and only experiences weak London dispersion forces due to the temporary dipoles that occur in nonpolar molecules.
Therefore, the molecule with the strongest intermolecular forces is A) HOCH2CHOHCHOHCH2OH.
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if the temperature of an aqueous solution of nacl is increased from 20 o c to 90 o c, which of the following statements is true? a. the density of the solution remains unchanged b. the molarity of the solution remains unchanged c. the molality of the solution remains unchanged d. the mole fraction of solute decreases e. the mole fraction of solute
Answers
If the temperature of an aqueous solution of NaCl is increased from 20 o c to 90 o c, it is true that C. The molality of the solution remains unchanged.
When the temperature of the aqueous solution of NaCl is increased from 20°C to 90°C, the density of the solution will increase, and the molarity of the solution will decrease. However, the molality of the solution will remain unchanged because the molality of a solution is defined as the number of moles of solute per kilogram of solvent, and the mass of the solvent does not change with temperature. The mole fraction of solute will also remain unchanged since the mole fraction is defined as the ratio of the moles of solute and the total number of moles of solute and solvent, and the number of moles of solute does not change with temperature.
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If the temperature of an aqueous solution of NaCl is increased from 20 o c to 90 o c, which of the following statements is true? a. the density of the solution remains unchanged b. the molarity of the solution remains unchanged c. the molality of the solution remains unchanged d. the mole fraction of solute decreases e. the mole fraction of solute increases
potassium-42 has a half-life of 12.4 hours. approximately how much of an 1202 mg sample of potassium-42 will be left after 2 days? group of answer choices
Answers
potassium-42 has a half-life of 12.4 hours. approximately how much of an 1202 mg sample of potassium-42 will be left after 2 days is 1522 mg.
a potassium isotope with a half-life of 12.36 hours that is synthesised artificially and is employed as a radioactive tracer in research on how much potassium is distributed in physiological fluids.
The time needed for a reactant's concentration to drop to half its initial value is a different method of describing reaction rates. The reaction's half-life, denoted by the symbol t1/2, is the duration of this time. Therefore, the reactant concentration must fall from [A]0 to [A]0/2 over the course of a reaction's half-life. The quicker reaction will have a shorter half-life if two reactions have the same order, while the slower reaction will have a longer half-life.
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what is the chemical formula for the compound formed between lithium and sulfur?
Answers
The chemical formula for the compound formed between lithium and sulfur is Li2S.
What is a chemical formula?
A chemical formula is a symbolic representation of a molecule that specifies the number and type of atoms within a molecule.
It depicts the proportion of each element in the molecule.
A chemical formula shows how many atoms of each element are present in a compound.
The chemical formula is a convenient method to communicate the identity of a molecule.
Lithium is a chemical element with the symbol Li and atomic number 3, and sulfur is a chemical element with the symbol S and atomic number 16.
These two elements react to form lithium sulfide.
Lithium and sulfur react to form a compound.
Two atoms of lithium and one atom of sulfur react to form one molecule of Li2S.
Therefore, the chemical formula for the compound formed between lithium and sulfur is Li2S.
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Formation of mature insulin includes all of the following except
A. removal of a signal peptide.
B. folding into a three-dimensional structure.
C. disulfide bond formation.
D. removal of a peptide from an internal region.
E.
-carboxylation of glutamate residues.
Answers
Formation of mature insulin includes all of the following except: E. carboxylation of glutamate residues.
The process of insulin maturation involves several steps. Initially, insulin is produced as a preproinsulin precursor, which contains a signal peptide that targets it to the endoplasmic reticulum (ER). The signal peptide is then removed (A) to form proinsulin. Proinsulin undergoes folding (B) into its three-dimensional structure, which is crucial for its biological activity.
During the folding process, disulfide bond formation (C) occurs, stabilizing the structure of insulin. These disulfide bonds are important for maintaining the stability and function of the mature insulin molecule.
Lastly, a peptide is removed from an internal region (D) of proinsulin to yield mature insulin, which consists of two polypeptide chains (A and B chains) connected by disulfide bonds.
Carboxylation of glutamate residues (E) is not involved in the formation of mature insulin. It is a post-translational modification that occurs in certain proteins but not in the process of insulin maturation.
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A gas has an initial volume of 15 L. If the temperature increases from 330 K to 450 K, what is the new volume.
Answers
Answer:
20.(45)L or about 20.4545L
Explanation:
PV = nRT
Where:
P - pressure
V - volume
n - number of particle moles
R - a constant
T - temperature in K
We can assume the P and n (and definitely R) stay the same, so we infer that
\(V_1 = \frac{nRT_1}{P} = 15L\\V_2 = \frac{nRT_2}{P}\\V_1 / V_2 = \frac{nRT_1}{P} / \frac{nRT_2}{P} = \frac{T_1}{T_2}\\\\15L / V_2 = \frac{330K}{450K} = \frac{11}{15}\\\\V_2 = 15L \cdot \frac{15}{11} = 20.(45)L\)
thermohaline circulation is driven by: group of answer choices the coriolis effect. longitude. density differences. wind. latitude.
Answers
thermohaline circulation is driven by: density differences
Mass per unit volume is measured using the density unit. Given that it is an intense property, the size of the item has no bearing on the value of the property. Density Physics-related meaning The mass-to-volume ratio of an object is known as its density in physics. Mass per unit volume is a frequent definition. Chemistry's use of density The density of a substance in chemistry is a measurement of how much mass there is per unit volume. It is a physical characteristic that is intense, which means that the size of the object has no bearing on its value.
thermohaline circulation is driven by: group of answer choices the coriolis effect. longitude. density differences. wind. latitude.
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Describe at least two different objects that you think are magnetic. Why do you think these objects are magnetic?
(That was a fake question). Real question is do you master,bate
Answers
Answer: yes but usally to Doujinshi
Explanation:cause it’s better then Real stuff I guess
Answer:
boy noooooo
Explanation:
Briefly answer the following questions, including reasoning and calculations where appropriate: (a) Explain in your own words why direct expansion systems require the vapour exiting the evaporator to be superheated. (8 Marks) (b) Describe the difference between a forced draft evaporator and an induced draft evaporator, and describe why (and in what type of system) a forced draft evaporator is often preferred over an induced draft evaporator. (6 Marks) (c) Determine the R-number of each of the following refrigerants, and hence classify them (ie chlorofluorocarbon, hydrocarbon etc): (i) CClF 2
CF 3
(3 Marks) (ii) Tetrafluoroethane (3 Marks) (iii) H 2
O (3 Marks) (d) Briefly describe the role of hydrogen gas in an absorption refrigeration system (NH 3
/H 2
O/H 2
). In a system where the evaporating temperature is −2.0 ∘
C, with a design condensing temperature of 38.0 ∘
C, estimate the partial pressure of hydrogen in the evaporator.
Answers
Direct expansion systems require the vapour exiting the evaporator to be superheated to avoid liquid slugging, to improve the effectiveness of the evaporator and to maintain the stability of the compressor. (B) Forced draft and induced draft evaporators differ in the way air is introduced into them. (C) CClF2CF3 (also known as R12) is a chlorofluorocarbon refrigerant. (ii) Tetrafluoroethane (also known as R134a) is a hydrofluorocarbon refrigerant and H2O is not classified as a refrigerant. (D) The partial pressure of hydrogen in the evaporator is 1.6 mmHg.
(a) Direct expansion systems are those in which the refrigerant in the evaporator evaporates directly into the space to be cooled or frozen. The evaporator superheat is used to make sure that only vapor and no liquid is carried over into the suction line and compressor. Superheating is required for the following reasons :
To avoid liquid slugging : Liquid slugging in the compressor's suction line can be caused by a lack of superheat, which can result in compressor damage. To improve the effectiveness of the evaporator : Superheating increases the evaporator's efficiency by allowing it to absorb more heat. To maintain the stability of the compressor : The compressor is protected from liquid by the correct use of superheat, which ensures that only vapor is returned to the compressor.(b) Forced draft and induced draft evaporators differ in the way air is introduced into them. In an induced draft evaporator, a fan or blower is positioned at the top of the evaporator, and air is drawn through the evaporator from the top. In a forced draft evaporator, air is propelled through the evaporator by a fan or blower that is located at the bottom of the evaporator. Forced draft evaporators are frequently used in direct expansion systems because they allow for better control of the air temperature. Because the air is directed upward through the evaporator and out of the top, an induced draft evaporator is less effective at keeping the air at a uniform temperature throughout the evaporator.
(c) (i) CClF2CF3 (also known as R12) is a chlorofluorocarbon refrigerant.
(ii) Tetrafluoroethane (also known as R134a) is a hydrofluorocarbon refrigerant.
(iii) H2O is not classified as a refrigerant.
(d) The function of hydrogen gas in an absorption refrigeration system (NH3/H2O/H2) is to increase the heat of reaction between ammonia and water.
The pressure of hydrogen gas in the evaporator of an absorption refrigeration system can be determined using the formula, Pa/Pb = (Ta/Tb)^(deltaS/R),
where Pa = partial pressure of hydrogen in the evaporator, Ta = evaporating temperature, Tb = condensing temperature, Pb = partial pressure of hydrogen in the absorber, deltaS = entropy change between the absorber and evaporator, R = gas constant.
Substituting the given values, Ta = −2.0 ∘C = 271 K ; Tb = 38.0 ∘C = 311 K ; Pb = atmospheric pressure = 1 atm ;
deltaS = 4.7 kJ/kg K ; R = 8.314 kJ/mol K
we get, Pa/1 atm = (271/311)^(4.7/8.314)
Pa = 0.021 atm or 1.6 mmHg
Therefore, the partial pressure of hydrogen in the evaporator is 1.6 mmHg.
Thus, Direct expansion systems require the vapour exiting the evaporator to be superheated to avoid liquid slugging, o improve the effectiveness of the evaporator and to maintain the stability of the compressor. (B) Forced draft and induced draft evaporators differ in the way air is introduced into them. (C) CClF2CF3 (also known as R12) is a chlorofluorocarbon refrigerant. (ii) Tetrafluoroethane (also known as R134a) is a hydrofluorocarbon refrigerant and H2O is not classified as a refrigerant. (D) The partial pressure of hydrogen in the evaporator is 1.6 mmHg.
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What element does Chlorine go in?
- metals
-not metals
-Metalloids
Answers
Answer:
non of them it is
halogen elements
Any 1 help with Chemistry here??
Answers
What is the chemical formula for Magnesium and Phosphorus as a compound?
1- Mg2 P5
2- Mg2 P3
3- Mg3 P2
4- Mg5 P3
Answers
The answer is Mg3 glad I helped