Answer:
Catalyst lower activation energy: TRUECatalyst are consumed by the overall reaction: FALSECatalyst speed up chemical reaction: TRUEExplanation:
Chemical reactions follow a path: reactants increase their chemical energies, form activated complexes (transition compounds) until reaching the activation energy, from which the final products are formed.
Catalysts are substances that can change the path of the reactions by lowering the activation energy (first statement is true) and, consequently, speeding up the reaction (third statement is true).
The activation energy is the minimum amount of energy required for the reactants to form the activated complex. So, catalysts, by providing a new path, where the activation energy is lower, manage to incrase the rate of the reaction.
But catalysts, although intervene in the reaction by modifying the way the reactants will react, do not form part of the reactants nor products, so they are not consumed by the overall reaction (second statement is false).
In chemistry, catalysts lower the activation energy thus speeding up chemical reactions, but they are not consumed by the reaction.
Explanation:The first statement, Catalysts lower activation energy, is true. Catalysts work by providing an alternative reaction pathway with a lower activation energy. This allows the reaction to proceed more rapidly.
The second statement, Catalysts are consumed by the overall reaction, is false. One of the key characteristics of a catalyst is that it is not consumed in the reaction. While it may temporarily bond with reactants during the process, it is released and available to participate in subsequent reactions.
The third statement, Catalysts speed up chemical reaction, is true. By lowering the activation energy, catalysts allows the reaction to occur at a faster rate.
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How does solar activity affect Earth?
When the sun becomes active, the occurrences of phenomena such as solar flares, coronal mass ejection become frequent. The amount of high-energy particles and extreme shortwave radiation released, such as X-rays and UV, will also increase. These phenomena affect the ionosphere of the Earth's atmosphere the most.
Match the words to the definitions below.
Question 1 options:
Turns litmus paper blue, taste bitter, donate OH- ions, feel slippery, 8-14 on pH scale.
The amount of ions per an amount of solvent. Ex: 10g salt/100g water
A lab procedure to deliver a measured volume of solution, generally measured in ml.
A substance or solution that resists changes in pH by stabilizing hydrogen ion concentration.
Turns litmus paper red, taste sour, donate H+, corrode metals, 0-6 on pH scale.
Logarithmic scale to indicate the amount of hydrogen ions in solution.
A chemical (dye created from lichens) that changes color in response to changes in pH.
Acids and bases are added proportionally and result in a chemical reaction that causes the pH of a solution to reach pH 7.
1.
Acid
2.
Base
3.
pH
4.
Concentration
5.
Buffer
6.
Litmus
7.
Neutralization
8.
Titration
Answer:
Explanation:
1. Turns litmus paper blue, taste bitter, donate OH- ions, feel slippery, 8-14 on pH scale.
BASE
BASE: A base is a substance that reacts with water to yield excess hydroxide ions.
Some of its characteristics are:
>It has a bitter taste
>Their aqeuos solutions have a soapy feel
>They have a PH greater than 7
>They turn red litmus paper blue
>They are electrolytes
2. The amount of ions per an amount of solvent. Ex: 10g salt/100g water
CONCENTRATION
Concentration is the amount of solute that can be found in a solution.
3. A lab procedure to deliver a measured volume of solution, generally measured in ml.
TITRATION
Titration is a laboratory procedure that is used to determine the amount of solution that is needed to drive a reaction to completion. It involves adding a solution to a known volume of another solution.
4. A substance or solution that resists changes in pH by stabilizing hydrogen ion concentration.
BUFFER
A buffer is solution that is made up of weak acids and their salts or weak bases and their salts. Such solutions are able to resist changes in PH
5. Turns litmus paper red, taste sour, donate H+, corrode metals, 0-6 on pH scale.
ACID
An acid is a proton donor, hydrogen ions.
Characteristics:
>Acids turns blue litmus paper red, they have sour taste and easily corrodes metals.
>They have a PH value between 0-6 on the scale.
>They are generally electrolytes
6. Logarithmic scale to indicate the amount of hydrogen ions in solution.
PH SCALE
A PH scale is a logarithmic scale that runs from 1-14 and is used to indicate the amount of hydrogen ions in a solution.
7. A chemical (dye created from lichens) that changes color in response to changes in pH.
LITMUS PAPER
Litmus paper is made of dyes created from lichen and it changes its color as PH changes. Acids turns blue litmus paper red while bases changes the color of litmus to blue from red. Litmus test is a popular test for solutions.
8. Acids and bases are added proportionally and result in a chemical reaction that causes the pH of a solution to reach pH 7.
NEUTRALIZATION
Neutralization is the reaction of acids and bases to produce salts and water. The endpoint of neutralization reaction signifies the point at which equal number of bases neutralizes an acid. The PH is 7 at this point.
The definitions for the provided words are as follows: 1. Base: Turns litmus paper blue, taste bitter, donate OH- ions, feel slippery, 8-14 on pH scale. 2. Concentration: The amount of ions per an amount of solvent. Ex: 10g salt/100g water. 3. Titration: A lab procedure to deliver a measured volume of solution, generally measured in ml. 4. Buffer: A substance or solution that resists changes in pH by stabilizing hydrogen ion concentration. 5. Acid: Turns litmus paper red, taste sour, donate H+, corrode metals, 0-6 on pH scale. 6. pH: Logarithmic scale to indicate the amount of hydrogen ions in solution. 7. Litmus: A chemical (dye created from lichens) that changes color in response to changes in pH. 8. Neutralization: Acids and bases are added proportionally and result in a chemical reaction that causes the pH of a solution to reach pH 7.
Explanation:1. Base: Turns litmus paper blue, taste bitter, donate OH- ions, feel slippery, 8-14 on pH scale.
2. Concentration: The amount of ions per an amount of solvent. Ex: 10g salt/100g water.
3. Titration: A lab procedure to deliver a measured volume of solution, generally measured in ml.
4. Buffer: A substance or solution that resists changes in pH by stabilizing hydrogen ion concentration.
5. Acid: Turns litmus paper red, taste sour, donate H+, corrode metals, 0-6 on pH scale.
6. pH: Logarithmic scale to indicate the amount of hydrogen ions in solution.
7. Litmus: A chemical (dye created from lichens) that changes color in response to changes in pH.
8. Neutralization: Acids and bases are added proportionally and result in a chemical reaction that causes the pH of a solution to reach pH 7.
The average kinetic energy of the particles in a sample of matter is measured as the ____.
A. chemical kinetics
B. thermochemistry
C. reaction rate
D. temperature
Answer:
D. Temperature
Explanation:
Temperature is not energy, let's just make that point first. So how can it be the average kinetic energy then?
Well, the short answer is, it is just a number. Temperature is a number that represents the average kinetic energy. It is important to note that temperature only relates to kinetic energy in substances.
This is what makes it different from heat. Heat considers all forms of energy in the substance.
Answer:
TEMPERATUE
Explanation:
What happens to a catalyst in a reaction?
Answer:
The catalyst is unchanged.
Explanation:
Hope my answer has helped you!
Help me on this question
Answer:
Explanation:
That's almost the exact definition of an ecosystem.
Hello!
I think an ecosystem because they are a biological community of interacting organisms and their physical environment. And that’s what an ecosystem is and it relates to your question.
I hope I answered in time!
Good luck!
~ Destiny ^_^
Of the reactions involved in the photodecomposition of ozone (shown below), which are photochemical? 1. o2 (g) + hν → o (g) + o (g) 2. o (g) + o2 (g) + m (g) → o3 (g) + m* (g) 3. o3 (g) + hν → o2 (g) + o (g) 4. o (g) + o (g) + m (g) → o2 (g) + m* (g)
Answer:
The answers are...
Explanation:
2 and 4.
Which answer describes a chemical reaction in equilibrium? (2 points)
The reactants are all used up.
All the product is formed.
The forward and reverse reactions have ceased.
The forward and reverse reaction rates are the same.
Answer:
It is the last option.
Explanation:.
The forward and reverse reaction rates are the same.
The concentration of reactants and products are constant.
You are given a solution of HCOOH (formic acid) with an approximate concentration of 0.20 M and you will titrate this with a 0.1105 M NaOH. If you add 20.00 mL of HCOOH to the beaker before titrating, approximately what volume of NaOH will be required to reach the end point? View Available Hint(s) You are given a solution of (formic acid) with an approximate concentration of 0.20 and you will titrate this with a 0.1105 . If you add 20.00 of to the beaker before titrating, approximately what volume of will be required to reach the end point? 11.1 mL 20.0 mL 72.4 mL 36.2 mL
Answer:
[tex]\boxed{\text{36 mL}}[/tex]
Explanation:
1. Write the balanced chemical equation.
[tex]\rm HCOOH + NaOH $ \longrightarrow$ HCOONa + H$_{2}$O[/tex]
2. Calculate the moles of HCOOH
[tex]\text{Moles of HCOOH} =\text{20.00 mL HCOOH } \times \dfrac{\text{0.20 mmol HCOOHl}}{\text{1 mL HCOOH}} = \text{4.00 mmol HCOOH}[/tex]
3. Calculate the moles of NaOH.
[tex]\text{Moles of NaOH = 4.00 mmol HCOOH } \times \dfrac{\text{1 mmol NaOH} }{\text{1 mmol HCOOH}} = \text{4.00 mmol NaOH}[/tex]
4. Calculate the volume of NaOH
[tex]c = \text{4.00 mmol NaOH } \times \dfrac{\text{1 mL NaOH }}{\text{0.1105 mmol NaOH }} = \textbf{36 mL NaOH }\\\\\text{The titration will require }\boxed{\textbf{36 mL of NaOH}}[/tex]
The volume of NaOH required to reach the end point is 36.2 mL
We'll begin by writing the balanced equation for the reaction.
HCOOH + NaOH —> HCOONa + H₂O
From the balanced equation above,
The mole ratio of the acid, HCOOH (nA) = 1
The mole ratio of the base, NaOH (nB) = 1
Finally, we shall determine the volume of the base, NaOHFrom the question given above,
Molarity of base, NaOH (Mb) = 0.1105 M
Volume of acid, HCOOH (Va) = 20 mL
Molarity of acid, HCOOH (Ma) = 0.2 M
Volume of base, NaOH (Vb) =?MaVa / MbVb = nA/nB
(0.2 × 20) / (0.1105 × Vb) = 1
4 / (0.1105 × Vb) = 1
Cross multiply
0.1105 × Vb = 4
Divide both side by 0.1105
Vb = 4 / 0.1105
Vb = 36.2 mLThus, the volume of the base, NaOH is 36.2 mL
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what do the symbols tell you about the conditions of the reaction shown to the right check all boxes that apply
Answer:
Sorry but erm was their supposed to be a image attach with it
Explanation:
Answer: options 1 and 4
Explanation:
What can acid rain do to buildings and statues
The chemicals that acid rain contains can have damaging effects on objects like buildings, monuments, statues, and cars.
Its components can make paint to be peel, stone construction appears old, worn down which reduces the architectural value and beauty.
ExplanationDepending on how acidic the rain is, it can obliterate these constructions to a brutal degree.
First, components like sulfurous, sulfuric and nitric acids mix with air and rain. Then they react with calcite or calcium-based compounds in marble and limestone and dissolve calcite.
The dry depositions of acidic particles contribute severely to the corrosion of construction materials, building paints, stones like marble, limestones and various type of granites.
Acid rains aggravate the life value of buildings and architectural structures.
An ethylene gas torch requires 3200 L of gas at 3.00 atm What will be the pressure of the gas if ethylene is supplied by a 250.0 L tank?
Answer:
38.4L
Explanation:
Given parameters of the ethylene gas:
Initial Volume V₁ = 3200L
Initial pressure P₁ = 3atm
Final Volume V₂ = 250L
Final pressure P₂ = ?
We need information about the unknown final pressure.
Based on the given parameters, we can apply Boyle's law. The law states that "the volume of a fixed mass of a gas is inversely proportional as the pressure changes if temperature is constant".
NB: We assume that the torch provides a constant source of heat.
The law is expressed mathematically as:
P₁V₁ = P₂V₂
Making the unknown P₂ the subject of the equation gives:
P₂ = P₁V₁ / V₂
P₂ = 3200x3/250
P₂ = 9600/250
P₂ = 38.4L
Pressure of the gas = 38.4L
Using Boyle's Law, we determined that the pressure of ethylene gas will be 38.4 atm when transferred from 3200 L at 3.00 atm to a 250.0 L tank.
To determine the final pressure of the ethylene gas when transferred into a different volume, we can use Boyle's Law.
Boyle's Law states that for a given mass of gas at constant temperature, the volume of the gas is inversely proportional to the pressure of the gas.Boyle's Law Formula
The formula used is :P₁V₁ = P₂V₂
Where:
P₁ = initial pressure (3.00 atm)V₁ = initial volume (3200 L)P₂ = final pressure (to be determined)V₂ = final volume (250.0 L)Rearranging the formula to solve for P₂ :
P₂ = [tex]\frac{P_{1} V_{1} }{V_{2} }[/tex]
Substituting in the given values:P₂ = [tex]\frac{3.00\times 3200 }{250.0}[/tex]P₂ = [tex]\frac{9600}{250.0}[/tex]P₂ = 38.4 atmTherefore, the pressure of the gas in the 250.0 L tank will be 38.4 atm.
Which pair of elements would most likely bond to form a covalently bonded compound?
Two non-metals pair of elements would most likely bond to form a covalently bonded compound.
What is an element?
It is defined as a substance which cannot be broken down further into any other substance. Each element is made up of its own type of atom. Due to this reason all elements are different from one another.
Elements can be classified as metals and non-metals. Metals are shiny and conduct electricity and are all solids at room temperature except mercury. Non-metals do not conduct electricity and are mostly gases at room temperature except carbon and sulfur.
The number of protons in the nucleus is the defining property of an element and is related to the atomic number.All atoms with same atomic number are atoms of same element.Elements combine to form compounds.
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Elements that are likely to form a covalent bond are typically nonmetals with similar electronegativity values, which leads to the sharing of electrons, as exemplified by the bonding of hydrogen and oxygen to form water (H₂O).
The question 'Which pair of elements would most likely bond to form a covalently bonded compound?' falls under the subject of Chemistry. When determining whether a pair of elements will likely form a covalent bond, we consider their electronegativity. Covalent bonds generally occur between nonmetallic elements that have similar electronegativity values, meaning they have a comparable ability to attract electrons.
For example, hydrogen (H) and oxygen (O) are both nonmetals and form a covalent bond to create water (H₂O). Another pair of elements that commonly form a covalent bond is nitrogen (N) and hydrogen (H), which combine to form ammonia (NH₃). These elements do not have markedly different electronegativities, which favors the sharing of electrons rather than the transfer of electrons which is characteristic of ionic bonding.
On the other hand, metals and nonmetals such as sodium (Na) and chlorine (Cl) tend to form ionic bonds, where electrons are transferred from one atom to another, due to their large difference in electronegativities.
What is true about the electrolysis of water? Use the picture to choose 2 correct answers.
Answer:
oxygen is produced at the anode and hydrogen gas is produced at the cathode
Explanation:
The statement true about electrolysis of water are;
Hydrogen gas is produced at the cathode.Oxygen gas is produced at the anode.What is electrolysis?Electrolysis is a process in which direct current is use to alter or change the chemical composition of a substance when the current is pass through it.
Therefore, The statement true about electrolysis of water are;
Hydrogen gas is produced at the cathode.Oxygen gas is produced at the anode.Learn more about electrolysis below.
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Explain why a balloon expands when taken to a higher elevation if the temperature remains constant? A) The decrease in atmospheric pressure allows the balloon wall to become more elastic. B) The decrease in atmospheric pressure relative to pressure inside the balloon causes it to expand. C) The increase in atmospheric pressure pushes the walls of the balloon outward thus making it larger. D) The increase in atmospheric pressure forces the gases to push harder on the balloon increasing its size.
Answer:
It seens like B would be the correct answer because the higher you go the less pressure is on the outside. think of it like a vacuum chamber, when you suck the air out there is less pressure on the inside, therefor if you were to put a balloon inside a vacuum chamber it would have a similar effect to the balloon high in the atmosphere
Explanation:
Answer:B
Explanation:
I did the USA testprep
When 0.5 g of powdered iron (III) oxide was added to 100 cm3 of hydrogen peroxide, water and oxygen were produced. Iron (III) oxide was not used up in the reaction. Based on the information, which of the following is likely to increase the rate formation of the products? Replacing the powdered iron oxide with its cubical crystals Using 150 cm3 of hydrogen peroxide Removing iron oxide from the reaction mixture Using 1.0 gram of iron oxide
Answer:
Using 1.0 gram of iron oxide.
Explanation:
Rate of the reaction depends on many factors:The concentration of the reactants.
The surface area of the reactants or catalyst.
The amount of the catalyst.
Hydrogen peroxide is the reactant and iron (III) oxide is the catalyst.
If we display the various choices:Replacing the powdered iron oxide with its cubical crystals:
This will decrease the surface area of the catalyst exposed to the solution, so the rate formation of the products will decrease.
Using 150 cm³ of hydrogen peroxide:
The volume of the reactant does not affect the concentration of the reactants, so changing the volume has no effect on the rate formation of the products.
Removing iron oxide from the reaction mixture:
Removing the catalyst will decrease (may stop) the rate formation of the products.
Using 1.0 gram of iron oxide:
This will increase the amount of the catalyst used, and so it will increase the rate formation of the products.
So, the right choice is:
the rate formation of the products
Which two forces drive the rock cycle?
A. Weathering and erosion
B. Transportation and deposition
C. Mineral composition of existing rock and time
D. Earth's internal heat engine and the water cycle
Answer:
D. Earth's internal heat engine and the water cycle
Explanation:
The rock cycle is driven by the earth's internal heat engine and the water cycle.
The internal heat engine furnishes the earth with the required energy. The energy is used to melt rocks within the earth crust and to initiate convective cells in the mantle. This causes rocks to melt and plates to move. As this occurs, igneous and metamorphic processes takes place.
The water cycle is greatly responsible for the weathering and erosion of rocks. Through these processes of denudation, sediments are formed and deposited within basins on the crust. The action of runing water and glacier plays a very significant role in forming sedimentary rocks.
The interplay between the internal heat Engine and water cycle moves crustal materials to deeper levels of the earth and also deep seated materials to the crust.
The two forces that primarily drive the rock cycle are Earth's internal heat engine and the water cycle. Therefore, option D is correct.
The Earth's internal heat engine, which includes processes like volcanic activity, tectonic plate movements, and mountain building plays a crucial role in the rock cycle.
These processes generate heat and pressure that lead to the formation of new rocks through processes such as solidification, crystallization, and metamorphism.
The water cycle, driven by solar energy, also plays a role as it contributes to weathering and erosion by causing precipitation, runoff, and the movement of water through different stages.
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I need help with this question I don’t understand it at all!!!
Answer:
C-14 => N-14 + β⁻
Explanation:
C-14 over time decays by beta emission to N-14. Before decay, C-14 nucleus contains 6 protons and 8 neutrons. It is accepted that a neutron (n°) is composed of 1 proton (p⁺) and 1 electron (e⁻). Beta emission indicates loss/discharge of a high energy e⁻ from the nucleus of C-14 leaving 7 protons and 7 neutrons. The number of protons defines the element, N-14 as a product of the decay process with the β particle (high energy electron) the other. To check, remember, the ∑mass Reactants = ∑mass Products (superscript numbers) and ∑reactant charges = ∑product charges (subscript numbers
₆C¹⁴ => ₇N¹⁴ + ₋₁e° or, C-14 => N-14 + β
Oxygen will have a positive oxidation number when combined with
Oxygen has a positive oxidation number when combined with fluorine, the most electronegative element, which always has an oxidation number of -1. This is an exception to oxygen's usual -2 oxidation state.
Explanation:Oxygen will have a positive oxidation number when combined with fluorine. This is because fluorine is more electronegative than oxygen, which is typically seen with an oxidation number of -2, except in this special case as well as in peroxides where it has an oxidation number of -1. Fluorine, the most electronegative element, always has an oxidation number of -1, and it is the only element with which oxygen can have a positive oxidation number.
For example, in compounds like dioxygen difluoride (O2F2), oxygen has a positive oxidation state. This is an exceptional situation, as oxygen usually exhibits a negative oxidation state due to its high electronegativity, only surpassed by fluorine. Remember, the sum of oxidation numbers in a compound must balance out to zero, or the charge of the ion if it is a polyatomic ion.
Why is the greenhouse effect important to life on earth
Answer:
Because Greenhouse gases let the sun's light shine onto the Earth's surface, but they trap the heat that reflects back up into the atmosphere. And this way, they act like the glass walls of a greenhouse. This greenhouse effect also keeps the Earth warm enough to sustain life.
Explanation:
Answer:
greenhouse gases trap heat for the earth so if it was unavaible no heat would be conserved
Explanation:
What sort of relationship is there between the molarity and the absorbance? What evidence is there for this claim?
The molarity of a solution is typically directly related to its absorption. This relationship is expressed through the Beer-Lambert law, and can be written as A=ecl. This is usually used in spectroscopy and research.
Hope this helps!
How do you do problem bii??
Answer:
Explanation:
Trick question. The cathode is where the reduction reaction takes place. The reduction reaction is the gain of electrons.
Pb+2 + 2e^- ===> Pb The eo for that is - 0.126.
The minus sign indicates that the Pb^2+ is not overjoyed at taking on those two electrons. If it had a say in the matter, it would rather be giving up electrons. In other words, it would rather be the oxidizing equation which would look like this
Pb ===> Pb+2 + 2e^- and the oxidizing potential would be eo = + 0.126
That's what moving right and moving left means. If the eo is - then the preferred reaction is the opposite one.
This is a real language problem and if Znk answers you can take his answer to the bank.
Answer:
[tex]\boxed{\text{(b) (ii) 0.34 V}}[/tex]
Explanation:
If electrons flow from Pb to X through the external circuit, the Pb electrode must be the anode.
The standard reduction potential for Pb²⁺ is -0.126 V.
When we write the half-reaction for the oxidation, the standard oxidation potential for Pb must be 0.126 V.
The cell reactions are:
E°/V
Anode: Pb ⇌ Pb²⁺ + 2e⁻ 0.126
Cathode: X²⁺ + 2e⁻ ⟶ X x
Overall: Pb + X²⁺ ⟶ Pb²⁺ + X 0.47
0.126 + x = 0.47
x = 0.47 – 0.126 = 0.34 V
[tex]\text{The reaction at the X electrode is a reduction,}\\\text{so its standard reduction potential is }\boxed{\textbf{0.34 V}}[/tex]
A saturated solution of silver nitrate is prepared in 100g of water at 20c. The solution is then heated to 50c. How much more silver nitrate must now be added to obtain a saturated solution?
Answer:
233 g.
Explanation:
It is known that:The solubility of silver nitrate at 20.0°C is 222 g per 100 g of water.
The solubility of silver nitrate at 50.0°C is 455 g per 100 g of water.
∴ We need to add (455 g - 222 g = 233 g) of AgNO₃ to obtain a saturated solution at 50.0°C.
Urgent 25 points!!
Amanda was asked to make a solution of salt water using 32.0 grams of NaCl and 0.75 Liter of water. Amanda realized that first, she needed to find the number of moles there are in 32 grams of NaCl. She set up the following calculation to find the number of moles of NaCl.
32.0 g NaCl x 1 mole NaCl = 0.55 moles of NaCl
58.45 g NaCl
A. Did Amanda find the number of moles of NaCl correctly? If not, explain.
B. What does Amanda need to do next to calculate the molarity of the NaCl solution? Show your work for full credit.
Answer:
A. Yes, Amanda find the number of moles of NaCl correctly.
B. 0.73 M.
Explanation:
A. Did Amanda find the number of moles of NaCl correctly? If not, explain.
Yes, Amanda find the number of moles of NaCl correctly.The relation to find the no. of moles of NaCl is:No. of moles (n) of NaCl = mass/molar mass.
mass of NaCl = 32.0 g, molar mass of NaCl = 58.45 g/mol.
∴ No. of moles (n) of NaCl = mass/molar mass = (32.0 g)/(58.45 g/mol) = (32.0 g NaCl)*(1 mol of NaCl)/(58.45 g NaCl) = 0.547 mol ≅ 0.55 mol.
B. What does Amanda need to do next to calculate the molarity of the NaCl solution? Show your work for full credit.
Molarity is the no. of moles of solute dissolved in a 1.0 liter of a solution.∴ M = (no. of moles of NaCl)/(volume of solution (L)) = (0.55 mol)/(0.75 L) = 0.73 M.
Substitution of an amino group on the para position of acetophenone shifts the cjo frequency from about 1685 to 1652 cm−1 , whereas a nitro group attached to the para position yields a cjo frequency of 1693 cm−1 . explain the shift for each substituent from the 1685 cm−1 base value for acetophenone
Answer:
Here's what I get.
Explanation:
The frequency of a vibration depends on the strength of the bond (the force constant).
The stronger the bond, the more energy is needed for the vibration, so the frequency (f) and the wavenumber increase.
Acetophenone
Resonance interactions with the aromatic ring give the C=O bond in acetophenone a mix of single- and double-bond character, and the bond frequency = 1685 cm⁻¹.
p-Aminoacetophenone
The +R effect of the amino group increases the single-bond character of the C=O bond. The bond lengthens, so it becomes weaker.
The vibrational energy decreases, so wavenumber decreases to 1652 cm⁻¹.
p-Nitroacetophenone
The nitro group puts a partial positive charge on C-1. The -I effect withdraws electrons from the acetyl group.
As electron density moves toward C-1, the double bond character of the C=O group increases.
The bond length decreases, so the bond becomes stronger, and wavenumber increases to 1693 cm¹.
Radium-223 is a radioactive isotope with a half-life of 11.4 days. how long (in days) will it be before 87.5% of the sample has decayed?
The decay constant here is 0.0607 day⁻¹. The sample will remains 34 days before its 87.5 decays.
What is nuclear decay?Heavy radioactive isotopes undergo decomposition into light nucleus by the emission of charged particles such as alpha or beta particles. The radioactive decay is a first order reaction. Thus, the decay constant k can be written as:
K = 1/t ln (W0/ Wt)
W0 is the initial amount of the sample an Wt be the weight after time t.
K can be related to the half time as follows:
k = 0.693/t1/2.
Given that, half life of the Ra sample is 11.4 days.
k = 0.693 / 11.4
= 0.0607 day⁻¹.
12.5 % of the sample remains after 87.5 % is decayed. The time take to decay its 87.5 % is :
t = ln (W0/Wt) / k
= ln (100/12.5) / 0.0607
= 34.4 days.
Therefore, the sample will remains 34.4 days before 87.5 % of it is decayed.
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Final answer:
Radium-223 will take approximately 11.1 days for 87.5% of the sample to decay, based on its half-life of 11.4 days.
Explanation:
11.1 days
83
Because each nuclide has a specific number of nucleons, a particular balance of repulsion and attraction, and its own degree of stability, the half-lives of radioactive nuclides vary widely. For example: the half-life of 203 Bi is [tex]1.9 × 10^19[/tex] years; 232 Ra is 24,000 years; 222 Rn is 3.82 days; and element-111 (Rg for roentgenium) is 1.5 × 10-³ seconds. The half-lives of a number of radioactive isotopes important to medicine are shown Table 21.2, and others are listed in Appendix M.
What is true about elements that are in the same column
There are made out of the same material or elements
How many grams of sodium chloride are required to prepare 500.0 ml of a 0.100 m solution?
Answer:
2.92 gExplanation:
1) Data:
a) V = 500.0 ml = 0.500 liter
b) M = 0.100
c) mass = ?
2) Formulae:
a) Molarity: M = n / V
b) Number of moles: n = mass in grams / molar mass
3) Solution
a) M = n / V ⇒ n = M × V = 0.1000 M × 0.500 liter = 0.0500 mol
b) molar mass NaCl = 58.443 g/mol
c) mass = n × molar mass = 0.0500 mol × 58.443 g/mol = 2.92 g
Answer: 2.92 g
Final answer:
To prepare a 0.100 M solution, you will need 2.922 grams of sodium chloride.
Explanation:
To calculate the grams of sodium chloride required to prepare a 0.100 M solution, we need to use the formula:
Molarity (M) = moles of solute / volume of solution (in liters)
First, we need to convert the volume of the solution from milliliters to liters:
500.0 mL = 0.5000 L
Next, we can use the formula to solve for moles of sodium chloride:
0.100 M = moles of NaCl / 0.5000 L
Since the molar mass of sodium chloride (NaCl) is 58.44 g/mol:
moles of NaCl = 0.100 M x 0.5000 L = 0.0500 moles
Finally, we can use the moles of sodium chloride to calculate the grams:
grams of NaCl = moles of NaCl x molar mass = 0.0500 moles x 58.44 g/mol = 2.922 g
If a wave has a wavelength of 13 meters and a period of 0.005, what's the velocity of the wave? A. 2,600 m/s B. 260 m/s C. 1,300 m/s D. 1,560 m/s
Answer:
V = 2600ms⁻¹
Explanation:
Given parameters:
Wavelength(λ) = 13meters
Period (T) = 0.005s
Period(T) is the time it takes for a full cycle of vibration to pass through. It's unit is in seconds (s)
The Velocity of waves is expressed as:
V = fλ
Where f = frequency(s⁻¹)
Frequency of a wave is the number of waves that passes through a point per unit time
f = 1/T
Where T is the period
We can therefore express Velocity of waves as a function of period
V = λ/T
Inputing the parameters, we have:
V = 13m / 0.005s
V = 2600ms⁻¹
Answer:
B) 2,600 m/s
Explanation:
Based on the equation, how many grams of Br2 are required to react completely with 36.2 grams of AlCl3?
AlCl3 + Br2 → AlBr3 + Cl2
Answer:
65.08 g.
Explanation:
For the reaction, the balanced equation is:2AlCl₃ + 3Br₂ → 2AlBr₃ + 3Cl₂,
2.0 mole of AlCl₃ reacts with 3.0 mole of Br₂ to produce 2.0 mole of AlBr₃ and 3.0 mole of Cl₂.
Firstly, we need to calculate the no. of moles of 36.2 grams of AlCl₃:n = mass/molar mass = (36.2 g)/(133.34 g/mol) = 0.2715 mol.
Using cross multiplication:
2.0 mole of AlCl₃ reacts with → 3.0 mole of Br₂, from the stichiometry.
0.2715 mol of AlCl₃ reacts with → ??? mole of Br₂.
∴ The no. of moles of Br₂ reacts completely with 0.2715 mol (36.2 g) of AlCl₃ = (0.2715 mol)(3.0 mole)/(2.0 mole) = 0.4072 mol.
∴ The mass of Br₂ reacts completely with 0.2715 mol (36.2 g) of AlCl₃ = no. of moles of Br₂ x molar mass = (0.4072 mol)(159.808 g/mol ) = 65.08 g.
Answer: 65.2 grams
Explanation:
Which is an overall third-order reaction?
a. R=k[A]2[b]
b.R= k[A][B]1
c. R=k [X]2[Y]3
d.R=k [x][y]
A on nudity
Reason: ye