Answers
Explanation:
i) Melting point = 15°C and Boiling point = 110°C
ii) The region C on graph there is only liquid state, the region A on graph there is only solid state.
iii) The straight line A1 - B1 shows that the melting point of solid wax and getting converted to liquid form.
iv) Latent heat of vaporization is a physical property of a substance.
It is defined as the heat required to change one mole of liquid at its boiling point under standard atmospheric pressure.
v) At 'B' the wax is at both solid and liquid state
Related Questions
which of the following pairs are ionic compounds ( Al,Cl),(Na,O),(Al,F)
Answers
Answer:
This answer I think it is Al,F
3. If there were multiple products comment on finding the mixture melting point of the products. Does your sample appear to be a mixture or pure
Answers
Answer:
If there were multiple products, we can take each product and mixed with a sample of a pure compound that we suspect might be the same as the product. Then, we taking the melting point of this mixture that contains one of our product and pure sample. Then, we can observe the change in melting point, if there is no change in melting point or the melting stays in the same range of the pure compound. Then, the that product along with the pure sample are actually the same compound, not a mixture of two compounds. However, if the melting point for our pure sample compound changed or didn't stay in the same range after the mixing with on of our products. then we can conclude that this product and the pure sample are completely different compound, and indeed they are a mixture.
The prosecution offers a lab report prepared by a government chemist who examined a white powdery substance seized from a box at Mary's house. The report indicated that the chemist used standard procedures in the analysis of the white substance, and the chemist prepared the report in the ordinary course of business. The report reflects the chemist's conclusion that the substance contained methamphetamine. Write a few sentences characterizing the report as either testimonial or nontestimonial hearsay.
Answers
Answer: The report prepared is a nontestimonial hearsay.
Explanation:
The nontestimonial hearsay can be defined as the expert opinion or statement given casually and not for the purpose of keeping or considering it as record by the government agent or agency. Here the given conclusion provided by the chemical expert is an example of nontestimonial hearsay because it is not the output of experimental and analytical procedures instead it is a casual opinion. Testimonial hearsay include the evidences that are based on detailed and thorough analytic procedures.
Consider the balanced reaction below:
2HBr + Ba(OH)2 → BaBr2 + 2H2O
How many moles of barium
hydroxide, Ba(OH)2, would be
required to react with 117 g hydrogen bromide, HBr?
Answers
Answer:
0.723 moles (5 s.f.)
Explanation:
Whenever there is a chemical equation, ensure that it is balanced. This is because a balanced chemical equation tells us the mole ratio (not the ratio of their masses), which means the relationship of the number of moles of reactants or products with one another.
The chemical equation given has already been balanced. Looking at the coefficients of HBr and Ba(OH)₂, the mole ratio of HBr to Ba(OH)₂ is 2: 1.
• 1 mole of Ba(OH)₂ is needed to react with 2 mole of HBr
Find the number of moles of HBr present:
Number of moles= mass ÷mr
Amount of HBr
= 117 ÷(1 +79.9)
= 1.4462 moles (5 s.f.)
Since the amount of Ba(OH)₂ required is half the amount of HBr present,
amount of Ba(OH)₂ required
= 1.4462 ÷2
= 0.723 moles (3 s.f.)
Notes:
• mr
= relative molecular mass
= sum of relative atomic masses (which can be found in the periodic table) in a molecule
Help me :( plzzzz :(
Answers
Answer: 1.80
Explanation:
One problem with using pesticides to control insects on crops is that the insects can develop resistance to the chemicals. How is this similar to the overuse of antibiotics?
Answers
Answer:
Explanation:
Overuse of antibiotics leads to bacteria's resistance against our drugs. This is increasing at an alarming rate and the reason is that overuse of antibiotics kills bacteria that lack the "resistance" gene or gene that can help them survive the antibiotics (similar is the case for insects that die to insecticides). But, some bacteria can have random mutations in their gene that can help them survive the antibiotic (similar is the case for some insects that can survive the insecticide), thus the surviving bacteria give rise to next generation of bacteria that are resistant to the given antibiotic (similar to how insects that survive the insecticide give birth to new insects that are resistant to insecticide too). Soon, every generation adds new antibiotic resistant bacteria (or new insecticide resistant insects in the case of insects) which is dangerous for all of life on this planet. Therefore, both are similar in the sense that new generations of these organisms will be resistant to our weapons against them.
Can someone do a True or false for these
Answers
Answer:
all i can accurately say is that 2 and 4 are both true
Using the diluted solution from the 100-mL volumetric flask, rinse a 1-mL vol. pipet with a few drops and then pipet exactly 1.00-mL into a 50-mL volumetric flask. (Take care not to pipet any solids.) Fill the 50-mL volumetric flask to the mark with acidic FeCl3 solution. Cap and invert to mix the solution. What color is the solution
Answers
Answer:
The color of the solution turned a clear brown sort of a copper color
Explanation:
The color of the solution turned a clear brown sort of a copper color.
This is because ASA and the FeCl3 are reacting in a manner that it is resulting in the creation of a metal.
It is known that oxygen contains 1 percent of the air. If 50 liters of wind, how much oxygen is needed? *
Answers
Answer:
25 PRECENT
Explanation:
An iron block of mass 18 kg is heated from 285 K to 318 K. If 267.3 kJ is required, what is the specific heat of iron?
A. 490.05
B. 158.77
C. 145.80
D. 450.00
Answers
Answer:
D. 450 J/kgK
Explanation:
Using the formula as follows:
Q = m × c × ∆T
Where:
Q = amount of heat absorbed/released (J)
m = mass of substance (g)
c = specific heat capacity
∆T = change in temperature (°C)
According to the information provided in this question:
Q = 267.3 kJ = 267300J
m = 18kg
∆T = 318K - 285K = 33K
c = ?
Q = m × c × ∆T
c = Q ÷ m∆T
c = 267300 ÷ 18 × 33
c = 267300 ÷ 594
c = 450 J/kgK
During an experiment, solid iodine was placed in a sealed container. The container was gradually heated and purple-colored vapors of iodine formed were observed. Describe this system when it reaches phase equilibrium.
Answers
Answer:
See explanation
Explanation:
A system is said to have attained dynamic equilibrium when the rate of forward reaction and the rate of reverse reaction are equal.
Considering the system under consideration;
I2(s)⇄I2(g)
Heating the container converts solid iodine to purple coloured iodine vapour.
At equilibrium, there will be no net change in the amount of solid iodine and iodine vapour present in the system because the two processes (forward and reverse reactions) occur at the same rate at equilibrium.
Which of the following is the best thermal insulator to reduce the transfer of
heat by convection?
A. Air
B. Water
C. Alcohol
D. A vacuum
Answers
Answer:
A
Explanation:
Not sure how to answer this:
A. Identify the side that is acidic
B. Explain why it's acidic
C. Identify the side that is basic
D. Explain why this side is basic
Answers
Answer:
A. The red side is acidic.
B. Because it has more positive hydrogen ions.
C. The blue side is basic.
D. Because it has more negative hydroxide ion.
Given the data from the question,
A. The side with more H⁺ is acidic
B. It is acidic because it contains more H⁺
C. The side with more OH¯ is basic
B. It is basic because it contains more OH¯
What is pH ?This is simply a measure of the acidity / alkalinity of a solution.
The pH measures the hydrogen ion concentration while the pOH measures the hydroxide ion concentration
pH scaleThe pH scale is a scale that gives an understanding of the variation of the acidity / alkalinity of a solution.
The scale ranges from 0 to 14 indicating:
0 to 6 indicates acid 7 indicates neutral 8 to 14 indicate basicHow to determine which side is acidic.The presence of H⁺ indicates acidity.
Thus, the side with more H⁺ is acidic.
How to determine which side is basicThe presence of OH¯ indicates the solution is basic.
Therefore, the side with more OH¯ is basic
Learn more about pH:
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The southernmost point of india is _____
(a) indra point
( b) Gulf
( c) Amaravati
(d) jarawas
Answers
Answer:
(a) indra pointExplanation:
Indira point is the southern most point of India and is situated on great nicobar island in the nicobar island.
Answer:
Your Ans Is
(A) Indra point.
How many cm3 in a L?
Answers
How to identify polar molecules
Answers
Answer:
Polar molecules occur when there is an electronegativity difference between the bonded atoms. Nonpolar molecules occur when electrons are shared equal between atoms of a diatomic molecule or when polar bonds in a larger molecule cancel each other out
Explanation:
need help really quickly!!
so how do you predict products when only reactants are given?
i can do everything else that’s asked for the hw but i don’t know how to do this one.
the first pair of reactants is calcium hydroxide + ammonium chloride.
Answers
Answer: so in this question are reactants are calcium hydroxide and ammonium chloride
Explanation: first of all know that a salt would be formed so here the salts present are calcium and chloride so they would react to form the salt calcium chloride, then since ammonium ions are present ammonia gas would be formed then, hydroxide ions (OH) are also present so water would be formed so our final products would be calcium chloride , ammonia and water .
WORD EQUATION
calcium hydroxide+ ammonium chloride⇒ calcium chloride+ ammonia+ water
CHEMICAL EQUATION
CA(OH)2+2NH4CL⇒ CACL2+2NH3+2H2O
ASAP PLEASE HELP What is the wavelength of a photon with a frequency of 6.56 x 1014 Hz?
A. 197 nm
B. 457 nm
O C. 303 nm
D. 435 nm
Answers
Answer:
B. 47 nm is the wavelength of a photon with a frequency of 6.56 x 1014 Hz.
Answer:
B. 457 NM ⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
What are the steps for writing the formula for a molecular compound? Naming a molecular
compound?
Answers
Answer:
Your question was explained in my chemistry book so I just shared the picture
Hope that helps
How is each nucleotide different from the others?
A. It has different bases.
B. It has different side chains.
C. It has different carboxyl groups.
D. It has different amine groups.
Answers
Answer:
a. po tamang sagot
Explanation:
pa pafoolow po pleasr
The DNA and RNA are polynucleotides which contain a chain of nucleotides monomers with different nitrogenous bases. Each nucleotide different from the others, as It has different bases. The correct option is A.
What is a nucleotide?A nucleotide is defined as a compound containing three component units, namely a pentose sugar (either ribose or 2-deoxyribose), a heterocyclic nitrogenous base (a substituted purine or a substituted pyrimidine) and a phosphate group.
The nucleotides are the phosphate esters of nucleosides. A nucleotide containing ribose as the sugar unit is termed as the ribonucleotide. While one containing 2-deoxyribose as the sugar unit is termed as the deoxyribonucleotide.
The nitrogenous bases in RNA are adenine, guanine, cytosine and uracil whereas in DNA the bases are adenine, guanine, cytosine and thymine. The purines are adenine and guanine whereas cytosine, thymine and uracil are pyrimidines.
Thus the correct option is A.
To know more about nucleotide, visit;
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If a man reach a 25 km distance in 30 min in his car , find the average velocity
Answers
Answer:
Average velocity of car = 50 km/h
Explanation:
Given information;
Distance cover by man in his car = 25 kilometer
Time taken by man to cover distance = 30 min
Find:
Average velocity of car
Computation:
Time taken by man to cover distance = 30 min
Time taken by man to cover distance = 30 / 60
Time taken by man to cover distance = 0.5 hour
Average velocity = Distance / Time
Average velocity of car = Distance cover by man in his car / Time taken by man to cover distance
Average velocity of car = 25 / 0.5
Average velocity of car = 50 km/h
Hands moving on a battery-operated clock is an example of what kind of
energy conversion?
A. Heat energy being converted to gravitational potential energy
B. Gravitational potential energy being converted to heat energy
C. Chemical potential energy being converted to kinetic energy
D. Kinetic energy being converted to chemical potential energy
Answers
Answer:
Chemical potential energy being converted to kinetic energy
Explanation:
In the hydrogenation of double bonds, a catalyst is needed. In the third step, the reactants react to form the product. This step is known as
Answers
Answer:
reaction
Explanation:
A reaction is defined as a process where the chemical transformation takes place from one form to some other form. Here, two different chemical substances are reacted together to form some other completely different product.
A hydrogenation process is a chemical process where between the molecular hydrogen and some another element or a compound. This process is usually carried out in the presence of catalyst mainly nickel, platinum or palladium.
Thus, in hydrogenation of a double bond, the catalyst is used to speed up the reaction. The first step in this process is adsorption process, the second step is the diffusion process, the third step is the reaction process and the last step is the desorption process.
Which best describes a swimming pool?
A.
It is a solute.
• B.
It IS
solvent.
C.
It is solution.
D.
It is a reactant.
•
E.
It is a product.
Answers
Answer:
Swimming pool is an example of solution
Explanation:
It has water (solvent) and dissolve ion (solute)
Answer:
it is a solution
Explanation:
the combining of (water and Cl and other pool chemicals) make it a solution.
How many O2 molecules react with 47 CH4 molecules according to the preceding equation CH4 + O2 → CO2 + H2O
Answers
You need to use stochio
What is the HCPCS Level II code for the compounded concentrated form of 0.5 mg Levalbuterol HCL when inhaled
Answers
Answer:
aefhfcjd
Explanation:
If aluminum is placed in an aqueous solution of silver nitrate and a single replacement reaction happens, what would be the balanced equation to represent the reaction?
Answers
Answer:
The balanced equation would be:
3AgNO3+Al→3Ag+Al(NO3)3
Explanation:
How many grams of ammonia can be produced from reacting a 450 L sample of nitrogen gas at a temperature of 450 K and a pressure of 300 atm?
Answers
Answer: The mass of ammonia is 124457.96 g which can be produced from reacting a 450 L sample of nitrogen gas at a temperature of 450 K and a pressure of 300 atm.
Explanation:
Given: Volume = 450 L
Temperature = 450 K
Pressure = 300 atm
The reaction equation is as follows.
[tex]N_{2} + 3H_{2} \rightarrow 2NH_{3}[/tex]
Here, 1 mole of nitrogen reacts to give 2 moles of ammonia.
From the given data, moles of nitrogen are calculated as follows.
PV = nRT
where,
P = pressure
V = volume
n = no. of moles
R = gas constant = 0.0821 L atm/mol K
T = temperature
Substitute the values into the above formula as follows.
[tex]PV = nRT\\300 atm \times 450 L = n \times 0.0821 L atm/mol K \times 450 K\\n = \frac{300 atm \times 450 L}{0.0821 L atm/mol K \times 450 K}\\= \frac{135000}{36.945}\\= 3654.08 mol[/tex]
For 3654.08 moles of nitrogen, the moles of ammonia produced is as follows.
[tex]2 \times 3654.08 mol\\= 7308.16 mol[/tex]
Therefore, mass of ammonia (molar mass = 17.03 g/mol) is calculated as follows.
[tex]Moles = \frac{mass}{molarmass}\\7308.16 mol = \frac{mass}{17.03 g/mol}\\mass = 124457.96 g[/tex]
Thus, we can conclude that the mass of ammonia is 124457.96 g which can be produced from reacting a 450 L sample of nitrogen gas at a temperature of 450 K and a pressure of 300 atm.
In the past mining companies were not made responsible for the clean-up of any of the mine sites. As a result, abandoned mines had a severe impact on the environment in Ontario. Which of these is not a result of these mining practices?
1) Chemical reactions producing sulphuric acid decrease soil and water PH in the area.
2) Acid leaching dissolves metals found in the soil thus allowing them to enter the water system.
3) Heavy metals which are left tailing ponds can dissolve and enter the water system.
4) Old and inefficient mining smokestacks contaminate the soils around abandoned mine sites.
Answers
Answer:
Old and inefficient mining smokestacks contaminate the soils around abandoned mine sites.
Explanation:
A smokestack, is a very tall channel commonly used in many instances to release gases produced by combustion processes directly into the air. These high towers are aimed at dispersing the gaseous pollutants over a wider area thereby minimizing their impact.
Old and inefficient smokestack do not contaminate the soil since they are very high towers that discharge gases directly into the atmosphere. Hence they are not part of the sources of soil contamination in abandoned mines.
In the experiment "Beer-Lambert’s Law and Spectrophotometry", you prepared a calibration plot similar to the one pictured below. What is the approximate concentration of a solution whose absorbance is 0.35?
Answers
Answer:
0.025M
Explanation:
As you must see in your graph, each concentration of the experiment has an absorbance. Following the Beer-Lambert's law that states "The absorbance of a solution is directely proportional to its concentration".
At 0.35 of absorbance, the plot has a concentration of:
0.025M