Answer:
None solutionExplanation:
When the variable adds out and the final sentence is false you have arrived to a contradiction, also called absurd, meaning that the starting equality was a wrong assumption that could never be true. Thus, the equation has no solutions.
An example of such situation is this equation:
x + 3 = x + 9To solve it, you use the subtraction property of the equalities: subtract both x and 3 from both sides:
x - x = 9 - 30 = 6The variable added out and the final sentences 0 = 6 is false. That means that none value of x satisfies the original equation and it has no solutions.
Answer:
It has 0 solutions
Explanation:
Zinc citrate is an ingredient in toothpaste. It is synthesis by the reaction of zinc carbonate with citric acid. Water and Carson dioxide are also produced
Answer:
I would answer if you had a question.
Find the empirical formula of the compound ribose, a simple sugar often used as a nutritional supplement. A 14.229 g sample of ribose was found to contain 5.692 g carbon, 0.955 g hydrogen, and 7.582 g oxygen. Show your work.
Answer:
CH2O
Explanation:
Firstly, we need to convert the masses of the elements to percentage compositions. This can be done by placing the mass of each element over the total mass multiplied by 100% . We can start with carbon.
C = 5.692/14.229 * 100 = 40%
O = 7.582/14.229 * 100 = 53.29%
H = 0.955/14.229 * 100 = 6.71%
We then proceed to divide each percentage composition by their atomic mass of 12, 16 and 1 respectively.
C = 40/12 = 3.333
O = 53.29/16 = 3.33
H = 6.71/2 = 6.71
Dividing by the smaller value which is 3.33
C = 3.33/3.33 = 1
O = 3.33/3.33= 1
H = 6.71/3.33 = 2
The empirical formula of the compound ribose is CH2O
Answer:
CH2O
Explanation:
First divide the given mass of each element by its relative atomic mass.
For carbon 5.692/12 = 0.47
For hydrogen 0.955/1 = 0.955
For oxygen 7.582/16= 0.47
Then we divide each by the lowest ratio
For carbon- 0.47/0.47 =1
For hydrogen- 0.955/0.47= 2
For oxygen- 0.47/0.47 = 1
Hence the empirical formula is CH2O
A swimming pool, 10.0 m by 4.0 m is filled to a depth of 3.0 m with water at a temperature of 20.0 degrees Celsius. How much energy is required to raise the temperature of the water to 30.0 degrees Celsius.
Answer:
5.01×10^9 J is the energy required
Explanation:
This is a calorimetry problem:
Q = m . C . ΔΤ where:
Q = heat
m = mass
ΔΤ = Final T° - Initial T°
First of all we determine the pool's volume with the measures
10 m . 4m . 3m = 120m3
As water density is 1g/mL we can determine water's mass but firstly we must convert the m3 to cm3
1mL = 1cm3
1m3 = 1x10^6 cm3
120 m3 . 1x10^6 cm3 / 1m3 = 1.2x10^8 cm3
Water density = water mass / water volume
1 g/ mL = water mass / 1.2x10^8 mL
Water mass = 1.2x10^8 g
Then, we replace the data in the formula
Q = 1.2x10^8 g .4.18 J/g°C (30°C - 20°C)
Q = 1.2x10^8 g . 4.18 J/g°C . 10°C
Q = 5016000000 joules
5.01×10^9 J
A barge loaded with lumber and iron ore floats in a lock by a dam (a closed pool of water like a big swimming pool). If some of the cargo is thrown overboard, the level of water in the lock will ___
Answer:
Rise
Explanation:
Because the cargo has no place to go it will make the water level rise
Digoxin is available in a concentration of 0.1 mg/ml. How many ml are required to administer a 75 mcg dose?
Answer : The volume required to administer a 75 mcg dose are, 0.75 mL
Explanation : Given,
Concentration of Digoxin = 0.1 mg/mL
That means, 0.1 mg of Digoxin present in 1 mL of solution.
Mass of dose = 75 mcg = 0.075 mg
Conversion used : (1 mcg = 0.001 mg)
Now we have to determine the volume required to administer a 75 mcg dose.
As, 0.1 mg of Digoxin required in 1 mL of solution
So, 0.075 mg of Digoxin required in [tex]\frac{0.075mg}{0.1mg}\times 1mL=0.75mL[/tex] of solution
Thus, the volume required to administer a 75 mcg dose are, 0.75 mL
What is the ratio of hydrogen atoms (HH) to oxygen atoms (OO) in 2 LL of water? Enter the simplest whole number ratio in order of hydrogen to oxygen, respectively. Express your answer as two integers, separated by a comma (e.g., 3,4).
Answer: 2, 1
Explanation:
Water has a formula as H2O.
Meaning it contains 2 atoms of Hydrogen and one atom of oxygen. No matter the volume of water, it will always contain 2 atoms of Hydrogen and one atom of oxygen. The ratio of hydrogen to oxygen in a water molecule is (2, 1)
Aluminum + oxygen yields aluminum oxide Write a balanced equation for this chemical reaction. A) Al + O → AlO B) Al + O → Al2O3 C) 2Al + 3O2 → Al2O3 D) 4Al + 3O2 → 2Al2O3
Answer:
Answer is D
Explanation:
The balanced equation for the reaction between aluminum and oxygen is: 4Al + 3O₂ -> 2Al₂O₃ (option D)
How to write balanced equation?Balanced equation can be written by ensuring that the reactants and products obtained from the reaction are balanced.
Now we can balanced the equation between aluminum and oxygen as follow:
Aluminum => AlOxygen => O₂Aluminum oxide => Al₂O₃Balanced equation =?Al + O₂ -> Al₂O₃
There are 2 atoms of O on the left side and 3 atom on the right. It can be balanced by writing 3 before O₂ and 2 before Al₂O₃ as shown below:
Al + 3O₂ -> 2Al₂O₃
There are 4 atoms of Al on the right side and 1 atom on the left. It can be balanced by writing 4 before Al as shown below:
4Al + 3O₂ -> 2Al₂O₃
Thus, the equation is balanced and the correct answer to the question is
4Al + 3O₂ -> 2Al₂O₃ (option D)
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Determine the magnitude of the acceleration experienced by an electron in an electric field of 664 N/CN/C .
Answer:
[tex]a=-1.17\times 10^{14} \hspace{3}\frac{m}{s^2}[/tex]
Explanation:
A charged particle that is in a region where there is an electric field, experiences a force equal to the product of its charge by the intensity of the electric field:
[tex]F_e=q*E[/tex]
If the electric field is uniform, the force is constant and so is the acceleration. Applying the equations of uniformly accelerated rectilinear motion, we obtain the velocity of the particle at any time or after having moved a certain distance:
[tex]a=\frac{qE}{m}[/tex] (1)
Where:
[tex]E=Electric\hspace{3}field\hspace{3}strength=664\frac{N}{C} \\q=Electric\hspace{3}charge\hspace{3}of\hspace{3}the\hspace{3}particle\\m=Mass\hspace{3}of\hspace{3}the\hspace{3}particle[/tex]
The electric charge and the mass of the electron are known constants:
[tex]q=-1.6\times 10^{-19} C\\m=9.1\times 10^{-31} kg[/tex]
So, replacing this data in the equation (1) :
[tex]a=\frac{(-1.6\times 10^{-19})*(664) }{9.1\times 10^{-31} } =-1.167472527\times 10^{14} \approx -1.17\times 10^{14} \hspace{3}\frac{m}{s^2}[/tex]
The minus sign is due to the fact that the charge is negative, therefore it experiences a force in the opposite direction to the field.
Cofactors are important because A. they are the building blocks of proteins. B. they signal cells to release enzymes. C. they prevent spikes in blood sugar. D. they serve to inactivate an enzyme, so as to better regulate chemical reactions. E. they enable enzymes to bind to their substrates.
Answer: E. they enable enzymes to bind to their substrates.
Explanation:
The cofactors are the molecules that help the enzyme catalyze the reactions. The Cofactor can be defined as a non-protein chemical compound that either loosely or tightly binds to the enzyme. This facilitates in performing the reactions that enzyme cannot perform alone. They can be divided into prosthetic group and coenzymes. The cofactors enhances the binding affinity of the enzymes with their substrates so that products can be formed.
Answer:
The answer is E: they enable enzymes to bind to their substrates.
Explanation:
Cofactors are inorganic substrates that are needed to: 1) produce a chemical reaction between the enzyme and the substrate, 2) increase the rate of catalysis, and 3) attach to the enzyme just like a prosthetic hand, to effectively allow enzymes carry out the catalysis of the reaction.
You happen to be visiting Northem California and you are driving by Suisun Bay, a notorious graveyard for old ships You notice that all of these ships appear to be nusting may Which of the following statements is true? View Available Hint(s The rusting of the metal is neither a chemical change nor a physical change O The rusting of the metal is a chemical change o The rusting of the metal is both a chemical change and a physical change The rusting of the metal is a physical change Submit the
Answer:
The rusting of the metal is a chemical change
Explanation:
Apparently, Rust is a product other than iron. Rusting is an example of a shift in chemistry. A chemical shift is also referred to as a chemical reaction which is a process that takes place as one or more compounds are converted into one or more different elements.
The formation of hydrated oxide, Fe(OH)3, FeO(OH), or even Fe2O3. H2O consists of the rusting of iron. It is an electrochemical phase requiring water, oxygen and an electrolyte to be present. No substantial rust occurs in the unavailability of any of these
The rusting of metal observed in Suisun Bay is a chemical change caused by a reaction between iron, oxygen, and water, forming iron oxides.
Explanation:Rusting of metal is a chemical change. When you notice ships rusting in Suisun Bay, what's occurring is a chemical reaction between the iron in the metal and oxygen from the air, often accelerated by water, which leads to the formation of iron oxides. This process, known as oxidation, results in the deterioration of the metal's quality and its structural integrity.
To illustrate the concept further:
A mirror being broken is a physical change because the chemical composition of the mirror remains the same, despite its fragmentation.An iron nail corroding in moist air exhibits a chemical change similar to those ships rusting, as the iron reacts with oxygen and water to form rust.Copper metal melting is a physical change because copper's chemical identity doesn't change when it shifts from solid to liquid form.A catalytic converter changing nitrogen dioxide to nitrogen gas and oxygen gas is another example of a chemical change because it results in new substances with different chemical properties.
On a hot sunny day, you get out of the swimming pool and sit in a metal chair, which is very hot. Would you predict that the specific heat of the metal is higher or lower than that of water? Explain.
Answer:
The specific heat capacity of the metal is lower than that of the water as explained as follows
Explanation:
The heat capacity is a measure of propensity of a given object or matter to undergo an increase or decrease in its temperature when subject a given amount of heat, in other words, for a given mass of the substance, it is the amount of heat required to be added to cause it to have a unit temperature change
The specific heat capacity of a material or substance is the amount of heat required to be supplied to raise the temperature of a unit mass of that by one degree Celsius. It is the ratio of the heat capacity of a specimen of a substance divided by the mass of the specimen
Both the water of the swimming pool, the swimmer and the metal chair are all exposed to the same amount of heat from the sun, however the heat required to raise the water temperture by one degree Celsius is higher than heat required to raise the temperature of the metal chair by one degree hence the chairs temperature is higher than the water temperature as shown in the following equation
ΔH = m₁ × C₁ × ΔT₁ = m₂ × C₂ × ΔT₂
Where ΔH = Heat or energy supplied from the sun
m₁ = mass of water in the swimming pool
C₁ = Specific heat capacity of the water in the swimming pool
ΔT₁ = Change in temperature of the swimming pool and
m₂ = mass of metal chair
C₂ = Specific heat capacity of the metal chair material
ΔT₂ = Change in temperature of the metal chair
Where ΔH is the same for both the chair and swimming pool with the chair being hotter than the swimming pool with an asumed temperature change of 1.5 times that of the swimming pool and assuming the same mass of both the swimming pool and the chair are measured we have
m₁ × C₁ × 1.5ΔT₂ = m₁ × C₂ × ΔT₂ then cancelling like terms we have
1.5C₁ = C₂
Hence the heat capacity of the swimming pool water is 1.5 times that of the metal chair
On a hot sunny day, when you sit in a metal chair and it feels very hot, it indicates that the metal has a lower specific heat than water.
Explanation:The specific heat of a material is a measure of the amount of heat energy required to raise the temperature of a given mass of the material by a certain amount. In this case, when you sit in a metal chair on a hot sunny day and it feels very hot, it indicates that the metal has a lower specific heat than that of water.
Metal is generally a good conductor of heat, which means it can rapidly transfer heat energy from the surroundings to your body when in contact. Water, on the other hand, has a higher specific heat and is a poor conductor of heat, so it takes longer to heat up and cool down.
The specific heat of metal depends on the type of metal. Different metals have different specific heat values.
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Consider the following specific heats: copper, 0.384 J/g· °C; lead, 0.159 J/g· °C; water, 4.18 J/g· °C; glass, 0.502 J/g· °C. Which substance, once warmed, would be more likely to maintain its heat and keep you warm through a long football game on a cold night? 1. glass 2. lead 3. water 4. copper
Water, having the highest specific heat of 4.18 J/g·°C among the substances listed, would be the best at maintaining its heat over time, making it the most suitable to keep warm during a long football game on a cold night.
The specific heat value of a substance is key for understanding which material would maintain heat longer. Based on the specific heat values provided, water, with a specific heat of 4.18 J/g·°C, would be the best at maintaining its heat through a long football game on a cold night. This is because the higher the specific heat, the more energy (heat) the substance can store and the longer it can release that heat over time, compared to substances with lower specific heats like copper, lead, or glass.
How does the potential energy of reactants compare to the potential energy of products in an endothermic reaction?
Answer:
Potential energy of reactants in an endothermic reaction is lower than the potential energy of products because in endothermic reaction system absorb energy from environment. We can see that in the lower temperature of environment after completed reaction.
Explanation:
The potential energy of products is less than the potential energy of the reactants.
Exothermic reactions are defined as the reactions which release heat. The release in heat is due to the difference in the potential energy of the reactants and the products.
For these reactions, the potential energy of the products is less than the potential energy of the reactants. The total enthalpy change of the reaction is given by the equation:
[tex]$\Delta H_{r x n}=\sum H_{\text {products }}-\sum H_{\text {reactants }}$[/tex]
An exothermic reaction [tex]$\Delta H_{r x n}$[/tex] is negative.
For the reaction of baking soda and vinegar, the equation follows:
[tex]$\mathrm{NaHCO}_{3}+\mathrm{CH}_{3} \mathrm{COOH} \rightarrow \mathrm{CH}_{3} \mathrm{COONa}+\mathrm{CO}_{2}+\mathrm{H}_{2} \mathrm{O}+$[/tex]
As the energy is written at the product side, this means that the reaction between baking soda and vinegar is an exothermic reaction.
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To treat a burn on his hand, a person decides to place an ice cube on the burned skin. The mass of the ice cube is 19.2 g, and its initial temperature is − 10.6 ∘ C. The water resulting from the melted ice reaches the temperature of his skin, 29.0 ∘ C. How much heat is absorbed by the ice cube and resulting water? Assume that all of the water remains in the hand.
Answer : The heat absorbed by the ice cube and resulting water is, 9.15 kJ
Solution :
The process involved in this problem are :
[tex](1):H_2O(s)(-10.6^oC)\rightarrow H_2O(s)(0^oC)\\\\(2):H_2O(s)(0^oC)\rightarrow H_2O(l)(0^oC)\\\\(3):H_2O(l)(0^oC)\rightarrow H_2O(l)(29.0^oC)[/tex]
The expression used will be:
[tex]\Delta H=[m\times c_{p,s}\times (T_{final}-T_{initial})]+m\times \Delta H_{fusion}+[m\times c_{p,l}\times (T_{final}-T_{initial})][/tex]
where,
[tex]\Delta H[/tex] = heat available for the reaction = [tex]4.50\times 10^3kJ=4.50\times 10^6J[/tex]
m = mass of ice = 19.2 g
[tex]c_{p,s}[/tex] = specific heat of solid water or ice = [tex]2.01J/g^oC[/tex]
[tex]c_{p,l}[/tex] = specific heat of liquid water = [tex]4.18J/g^oC[/tex]
[tex]\Delta H_{fusion}[/tex] = enthalpy change for fusion = [tex]6.01kJ/mole=6010J/mole=\frac{6010J/mole}{18g/mole}J/g=333.89J/g[/tex]
Molar mass of water = 18 g/mole
Now put all the given values in the above expression, we get:
[tex]\Delta H=[19.2g\times 2.01J/g^oC\times (0-(-10.6))^oC]+19.2g\times 333.89J/g+[19.2g\times 4.18J/g^oC\times (29.0-0)^oC][/tex]
[tex]\Delta H=9147.1872J=9.15kJ[/tex]
Therefore, the heat absorbed by the ice cube and resulting water is, 9.15 kJ
Jackie goes camping in the Nowhere mountains and brings a few pots and pans to cook. On top of Nowhere mountain (at 3,000 feet above sea level), Jackie realizes her soup cooks much faster than at her house in Austin, TX (at sea level). Explain why this is.
This is because of the low pressure at the mountains.
Explanation:The air pressure or atmospheric pressure is defined as the amount of pressure exerted by the air column of the atmosphere above in the atmosphere per unit area. This air pressure is inversely proportional to the height of the land above sea level. As we go up in the atmosphere, the pressure of Air decrease.
As Jackie goes in the mountains for his picnic, the pressure of air at the mountains is much lower than at her house in Austin, because Austin is at sea level. So water will boil much faster owing to low pressure. Thus, water is boiling at lower temperature. And this low temperature is easily and quickly achievable. So Austin seems that her soup is ready much faster. But the veggies and meat won't be fully cooked at that temperature. So although the soup seems to be ready, it isn't.
For KNO3 the heat of solution is 23.8 kJ/mol and the lattice energy is -685.0 kJ/mol. Calculate the heat of hydration.
Answer: The heat of hydration for potassium nitrate is 708.8 kJ/mol
Explanation:
We are given:
Heat of solution for potassium nitrate = 23.8 kJ/mol
Lattice energy for potassium nitrate = -685.0 kJ/mol
Heat of hydration for potassium nitrate = ?
To calculate the heat of hydration, we use the equation:
Heat of the solution = Heat of hydration + Lattice energy
Putting values in above equation, we get:
[tex]23.8=\text{Heat of hydration}+(-685.0)\\\\\text{Heat of hydration}=23.8-(-685.0)\\\\\text{Heat of hydration}=708.8kJ/mol[/tex]
Hence, the heat of hydration for potassium nitrate is 708.8 kJ/mol
Which orbitals form a pi bond?
A.the s orbital and three p orbitals
B.the s orbital and two p orbitals
C.overlapping p orbitals
D.overlapping hybrid orbitals
Answer:
C.overlapping p orbitals
Explanation:
The atoms which comprises of single bond is formed by sigma bond. Sigma bond is formed by the internuclear overlapping of the atomic orbitals. They are formed due to the head on overlapping of the atomic orbitals. Since, the bond is symmetrical about the internuclear axis, it can rotate without the breakage of the bond.
On the other hand, double or triple bonds contains one or two pi bonds respectively along with one sigma bond. Pi bonds are formed by the sideways overlapping and thus they are non-symmetrical about the internuclear axis and thus it breaks if the bond is being rotated.
Thus the answer is:- C.overlapping p orbitals
Final answer:
Pi bonds are formed by the side-by-side overlap of unhybridized p orbitals on adjacent atoms, such as in the carbon atoms of an alkene. The correct answer for which orbitals form a pi bond is C: overlapping p orbitals.
Explanation:
The pi bond (π bond) typically involves the side-by-side overlap of p orbitals that are unhybridized. Notably, pi bonding can also occur with d orbitals or with p orbitals that are part of hybrid orbitals, under certain circumstances. However, in the context of this question and in typical organic structures like ethene (C₂H₄), a pi bond is the result of the sideways overlapping of p orbitals on adjacent carbon atoms. Each has one electron and is perpendicular to the line formed by the sigma bonds in the molecule.
For the given options, the correct answer is C: overlapping p orbitals, which align perpendicularly to the molecular plane formed by sigma bonds and overlap side-by-side to form a pi bond. Therefore, it is the p orbitals that must be unhybridized, as they are in the sp2 hybridization state observed in alkenes such as ethene, where each carbon atom has three sp2 hybrid orbitals in a plane and the unhybridized p orbital perpendicular to that plane leading to pi bonding.
If the kinetic energy of a particle is equal to twice its rest mass, what is the velocity of the particle? Determine if relativistic calculations are required?
Answer:
The velocity of the particle is 2 m/s,
Explanation:
Kinetic energy is defined as energy of the body due to its motion. It is given by :
[tex]K.E=\frac{1}{2}mv^2[/tex]
Where :
m = mass of the object
v = velocity of the object
We have , particle with mass m and its kinetic energy is twice its mass.
[tex]K.E=2m[/tex]
[tex]2m=\frac{1}{2}mv^2[/tex]
[tex]v^2=\frac{4}{1}[/tex]
[tex]v=2[/tex]
And unit of velocity are m/s , so the velocity of the particle is 2 m/s.
Final answer:
To find the velocity of a particle whose kinetic energy is twice its rest mass, we use relativistic mechanics and find that the velocity is approximately 0.943c. This indicates that relativistic effects are significant and must be considered.
Explanation:
When the kinetic energy (KE) of a particle is twice its rest mass energy (E0), relativistic calculations are needed due to the comparably large energy involved. The rest mass energy is given by the famous equation E0 = mc², where m represents the rest mass and c is the speed of light.
To find the velocity, we use the relativistic relationship between energy and velocity:
KE = (γ - 1)mc², where γ is the Lorentz factor, defined as γ = 1/ √(1 - v²/c²).
Given that KE is twice the rest mass energy (E0), it follows that:
2mc² = (γ - 1)mc²
We can cancel mc² on both sides and solve for γ:
2 = γ - 1 → γ = 3
Now, we can solve for v:
3 = 1/ √(1 - v²/c²)
√(1 - v²/c²) = 1/3
1 - v²/c² = 1/9
v²/c² = 8/9
v = c √(8/9)
v = 0.943c
Therefore, the velocity of the particle is approximately 0.943 times the speed of light, indicating that relativistic effects are indeed significant and must be taken into account.
20 POINTS WILL GIVE BRAINLY IF ANSWERED CORRECTLY
When you squeeze an air-filled balloon, what happens inside?
A. The temperature inside the balloon decreases.
B. There is no change in the number of collisions of air molecules against the wall of the balloon.
C.There are fewer collisions of air molecules against the wall of the balloon.
D.There are more collisions of air molecules against the wall of the balloon.
Answer:
D
Explanation:
The answer is D- There are more collisions of air molecules against the wall of the balloon.
Squeezing an air-filled balloon increases the number of collisions of air molecules with the wall of the balloon, leading to more pressure inside and potentially a higher temperature.
Explanation:When you squeeze an air-filled balloon, the correct answer is D. There are more collisions of air molecules against the wall of the balloon. This is because squeezing the balloon increases the pressure inside it as the volume available to the gas molecules is reduced. Given a constant amount of gas, compressing it makes the molecules collide more frequently with the walls of the balloon. According to the principles of kinetic molecular theory, increased pressure results from an increased number of collisions. This can raise the temperature inside the balloon, as suggested by the relationship described in Charles's Law, which states that volume and temperature are directly proportional when the pressure is held constant. However, if the pressure increases due to compression, this does not necessarily indicate a change in temperature, as that depends on energy transfer, which is not specified in the scenario. Instead, it is the frequency of molecular collisions that increases.
WHAT IS THE DEFINITION FOR ISOTOPES, WHAT ARE EXAMPLES OF ISOTOPES, WHAT ARE NON EXAMPLES OF ISOTOPES AND WHAT ARE EXAMPLES OF ISOTOPES?
WILL MAKE BRAINLIEST (THE FIRST PERSON TO ANSWER CORRECTLY)
Isotopes are versions of a chemical element with different neutron numbers. Examples are Hydrogen-1, 2, and 3. Non-examples would be different elemental atoms.
Explanation:Isotopes are variants of a particular chemical element which differ in neutron number, and consequently in nucleon number. All isotopes of a given element have the same number of protons but different numbers of neutrons in each atom.
Examples of isotopes include Hydrogen-1 (Protium), Hydrogen-2 (Deuterium), and Hydrogen-3 (Tritium) - all are isotopes of hydrogen but have different numbers of neutrons. Non-examples of isotopes would be atoms of different elements, like a helium atom (2 protons) compared with a hydrogen atom (1 proton).
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Johnny is very careless in the lab. He purified two white solids (A and B) by re-crystallization, but forgot to label the vials. Both A and B have a melting point range of 10² - 10⁴ °C, so he is not sure which solid is which. He has a small amount of an authentic sample of pure A available in the lab. What should he do?
Answer:
The solution are in the explanation below
Explanation:
- Find the melting point of authentic sample of pure A.
- Mix sample A into both vials.
- Use melting point depression
- Lower melting component will liquefy first, and melting point will lower/broaden the range. (Determine which vial holds sample B mixed with A)
- Vial with the same sample A melting point range would remain consistent to 102-104˚C.
Johnny can identify the unknown samples A and B by conducting a melting point analysis with a mixture of the unknown and a known authentic sample of A. A unchanged melting point indicates the unknown is A, while a changed range suggests it is B. Proper technique is necessary for accurate results.
Johnny should perform a melting point analysis to determine which vial contains which substance. He can take a small amount of the authentic sample of pure A and mix it with a small amount of the unknown substance. He should then measure the melting point range of the mixture. If the mixture has a sharp, unchanged melting point range similar to the authentic sample's known value, it can be concluded that the unknown substance is also substance A. If the melting point range is depressed or broadened, it indicates the unknown substance is not A, but rather substance B.
It is important to note that if the expected melting point is not known, the substance should be heated at a medium rate to determine an approximate melting point. A second attempt should be made with a fresh sample for accuracy. Additionally, ensuring that the amount of solvent is suitable for the volume of the flask, and that heat is properly trapped can guarantee optimal re-crystallization conditions.