Answer:
Half-life for this reaction is 2.56s
Explanation:
The general expression in a reaction that follows first-order is:
Ln[A] = -kt + ln[A]₀
Where [A] is concentration of reactant after time t,
k is rate constant = 0.271s⁻¹
[A]₀ is initial concentration of reactant.
Half-life is defined as the time required to decrease the initial concentration of the reactant (I2 in this case) halved.
If [A]₀ = 1
[A] = 1/2
Solving the equation:
Ln[1/2] = -0.271s⁻¹*t + ln[1]
Ln[1/2] = -0.271s⁻¹*t + 0
Ln[1/2] = -0.271s⁻¹t
Ln 2 = 0.271s⁻¹
2.56s = t
Half-life for this reaction is 2.56s
if I am on a bus and I'm relative to A the student sitting next to me B relative to the house the bus goes by?
I want to prepare 4 Liters of 0.25 M aqueous sodium chloride solution. How many grams of the salt will I need to weigh out?
Answer:
Mass = 58.5 g
Explanation:
Given data:
Volume of solution = 4 L
Molarity of solution = 0.25 M
Grams of NaCl required = ?
Solution:
Formula:
Molarity = number of moles / volume in L
By putting values,
0.25 M = number of moles / 4 L
Number of moles = 0.25 mol/L × 4 L
Number of moles = 1 mol
Mass in gram:
Mass = number of moles × molar mass
Mass = 1 mol × 58.5 g/mol
Mass = 58.5 g
The half-life for a first-order reaction is 32 s. What was the original concentration if, after 2.0 minutes, the reactant concentration is 0.062 M?
Answer:
0.834 M.
Explanation:
Hello!
In this case, since this is a first-order reaction, we can infer that the half-life and the rate constant are related via:
[tex]t_{1/2}=\frac{ln(2)}{k}[/tex]
Thus, we are able to compute the rate constant:
[tex]k=\frac{ln(2)}{t_{1/2}} =\frac{ln(2)}{32s}\\\\k=0.0217s^{-1}[/tex]
Next, since we have the resulting concentration of the reactant and we need the initial one, we proceed as shown below with the rate law:
[tex]A=A_0exp(-kt)\\\\A_0=\frac{A}{exp(-kt)} \\\\A_0=\frac{0.062M}{exp(-0.0217s^{-1}*2.0min*\frac{60s}{1min} )}\\\\A_0=0.834M[/tex]
Best regards!
PLEASE HELP!!! WILL MARK BRIANLIST DO NOT GUESS I HAVE ATTEMPTED THREE TIMES
what is the correct?
Answer:
it is c
Explanation:
How many protons are in an element with an atomic number of 8 and mass number of 18
Answer:8
Explanation:
Atomic number = 8
Mass number = 18
The number of protons and the number of electrons is equal to the atomic number.
The number of neutrons in the nucleus is given by the difference in mass number and atomic number.
So, number of protons are 8
number of electrons = 8
number of neutrons = 18 - 8 = 10
5. What percentage of energy generation is
produced by fossil fuels? sc.7.P.11.2
to
(A) 19.5%
B) 33.2%
66.9%
D 86.4%
Answer:
It's actually D. 86.4%
Explanation:
When you combine coal, other gases, petroleum, nuclear, and natural gas, you get 86.4, which is the correct answer.
How does heat differ from temperature?
O Temperature is the measure of heat.
O Temperature and heat are the same thing.
O Temperature measures thermal energy, and heat is the flow of thermal eneroy
O Temperature measures the loss of energy, and heat measures the gain of eneray.
Answer: Temperature measures thermal energy, and heat is the flow of thermal energy
Explanation:
Heat describes the transfer of thermal energy between molecules within a system. Heat measures how energy moves or flows. It is measured in Joules.
Temperature measures the hotmess or coldness of a body or how much thermal energy it contains . Temperature describes the average kinetic energy of molecules within a material or system. It is measured in Celsius (°C), Kelvin(K), or Fahrenheit (°F).
Thus the correct option is Temperature measures thermal energy, and heat is the flow of thermal energy
Answer:
its c
Explanation:
edg 2021
The rearrangement which most likely occurs in the following reaction can be described as a
HBr
(CH3)2CHCH=CH2 →
a. hydride shift from C-2 to C-1.
b. hydride shift from C-3 to C-2.
c. proton shift from C-2 to C-1.
d. methyl group shift from C-3 to C-2.
Answer:
b. hydride shift from C-3 to C-2.
Explanation:
Markovnikov's rule states that *in the addition of a protic acid HX or other polar reagent to an asymmetric alkene, the acid hydrogen (H) or electropositive part gets attached to the carbon with more hydrogen substituents, and the halide (X) group or electronegative part gets attached to the carbon with more alkyl substituents* (wikipedia).
This rule implies that the hydrogen of HBr will be attached to C-1 and the carbocation will be on C-2. Remember that the order of stability of carbocations is tertiary > secondary > primary > methyl. A hydride shift can yield a tertiary carbocation.
C-3 is a tertiary carbon atom. If the hydride on carbon 3 shifts to carbon 2, a tertiary and more stable carbocation is formed. This accounts for the major product in the reaction.
Calculate the pH after 10.0 mL of 0.125 M NaOH is added to 30.0 mL of 0.105 M HCHO2.
Ka (HCHO2) = 1.8 × 10-4
Answer:
pH = 3.57 after adding 10ml of 0.125M NaOH
Explanation:
NaOH + HCHO₂ => NaCHO₂ + H₂O
=> 10ml(0.125M NaOH) + 30ml(0.030M HCHO₂)
=> 0.01(0.125)mol NaOH + 0.036(0.030)mol HCHO₂ ***(see reference note at end of problem)
=> 0.00125mol NaOH + 0.00315mol HCHO₂
=> (0.00315mol - 0.00125mol) HCHO₂ = 0.0019mol HCHO₂ in excess
+ 0.00125mol NaCHO₂ formed.
HCHO₂ ⇄ H⁺ + CHO₂⁻
C(i): 0.0019mol/0.040L 0.00M 0.00125mol/0.40L
= 0.0475M = 0.0313M
ΔC: -x +x +x
C(eq): 0.0475 - x x 0.0313 +x
Ka = [H⁺][CHO₂⁻]/[HCHO₂] = (X)(0.0313 + x)/(0.0475) = 1.8 X 10⁻⁴
=> x² + 0.03168x + (-8.55 x 10⁻⁶) = 0
Solve with quadratic equation ...
x = 2.68 x 10⁻⁴M = [H⁺] at equilibrium
pH = - log[H⁺] = -log(2.68 x 10⁻⁴) = -(-3.57) = 3.57
___________________________________
*** remember, => moles = Molarity x Volume in Liters
How many centimeters make an inch?
Answer:
2.54 Centimeters.
After watching the morning news, roommates Kelly and Rob argued about whether or not a man on trial should have been sentenced to prison for robbing goods and giving to those on welfare. Rob argued that the man should not have been convicted because he broke the law for a good cause while Kelly argued that the man should be convicted because it is against the law to steal so the man's behavior was wrong.
Based on Lawrence Kohlberg's theory of moral reasoning which of the following statements would Kohlberg agree with?
A.
Kelly is at a higher level of moral reasoning than Rob.
B.
Rob is at a higher level of moral reasoning than Kelly.
C.
Rob and Kelly are at the same level of moral reasoning.
D.
Rob has more knowledge than Kelly concerning criminal behavior.
Answer:
B) rob is at a higher level of moral reasoning than kelly
Explanation:
i just took the quiz on edge 2020
Based on Lawrence Kohlberg's theory of moral reasoning statement with which Kohlberg agree with is that Rob is at a higher level of moral reasoning than Kelly.
What is moral reasoning?Moral reasoning is an important and often daily process that people use when trying to do the right thing. For instance, every day people are faced with the dilemma of whether to lie in a given situation or not. People make this decision by reasoning the morality of their potential actions, and through weighing their actions against potential consequences.
A moral choice can be a personal, economic, or ethical one; as described by some ethical code, or regulated by ethical relationships with others. This branch of psychology is concerned with how these issues are perceived by ordinary people, and so is the foundation of descriptive ethics. There are many different forms of moral reasoning which often are dictated by culture.
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Phenylephrine is a nasal decongestant and is the active ingredient in Sudafed, which contains phenylephrine hydrochloride (PEHCL). The conjugate acid (PEH+) of phenylphrine has a pKa = 5.5. At a physiological pH of 7.4. what is the ratio of concentrations, [PE]/[PEH+]?
Answer:
The ratio of concentrations is 79.4
Explanation:
Using Henderson-Hasselbalch equation we can solve the [PE]/[PEH+] ratio:
pH = pKa + log [A-] / [HA]
Where pH is 7.4
pKa of the phenylphrine is 5.5
[A-] is the weak base = [PE]
And [HA] is the conjugate acid [PEH+]
Replacing:
7.4 = 5.5 + log [PE] / [PEH+]
1.9 = log [PE] / [PEH+]
79.4 = [PE] / [PEH+]
The ratio of concentrations is 79.4
Perform the following operation
and express the answer in
scientific notation.
4.3x102 -7.0x 102
Answer:
-2.7 ×10²
Explanation:
Scientific notation is the way to express the large value in short form.
The number in scientific notation have two parts.
. The digits (decimal point will place after first digit)
× 10 ( the power which put the decimal point where it should be)
for example the number 6324.4 in scientific notation will be written as = 6.3244 × 10³
Given measurements = 4.3×10² - 7.0 ×10²
= -2.7 ×10²
Ethanol has the chemical formula C2H5OH. Write and balance the chemical reaction for the combustion of ethanol
Answer:
C2H5OH(l)+3O2(g)⟶2CO2+3H2O(l)
Explanation:
The balanced equation for the combustion of ethanol will be
[tex]C_{2}H_{5}OH+3O_{2}------- > 2CO_{2}+3H_{2}O[/tex]. According to this carbon dioxide and water will be the product.
What is combustion?
Combustion is a chemical process during which a material reacts quickly with oxygen and generates heat.
The original substance is referred to as the fuel, and the supplier of oxygen is referred to as the oxidizer. The fuel can be solid, liquid, or gas, but it is usually a liquid for airplane propulsion.
Combustion is a chemical reaction between two or more substances, usually involving oxygen, that produces light and heat in the form of a flame.
The products of complete ethanol combustion are carbon dioxide and water, as well as the start releasing of light and heat.
The equation will be:
[tex]C_{2}H_{5}OH+3O_{2}------- > 2CO_{2}+3H_{2}O[/tex]
Thus, in this way, the combustion of ethanol occurs.
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What do u call a snowman in the summer
Answer:
A puddle
Explanation:
BAHAHAHAHA
How can high-altitude training help athletes get more oxygen to their cells
Answer:
the altitude in witch the athlete is running candy help them run faster useing less energy
The athletes acclimate to high altitudes, they have more red blood cells which allow their blood to inhale more oxygen.
Does working at higher altitudes increase red blood cells?In high-altitude environments, we breathe less oxygen per breath than at lower altitudes. Each breath delivers less oxygen to the muscles of our body. In higher altitudes, a person is getting used to breathing “thinner” air which can enhance athletes’ athletic performance.
Training at high altitudes, feel like they’re putting forth more effort to perform and they do closer to sea level. The increased rate of exertion is caused by hypoxia, which is a reduction in the amount of oxygen to the muscles to burn fuel and produce energy.
Athletes acquire more red blood cells which offer their blood to hold more oxygen. They get a natural boost to the muscles when additional oxygen is available when they compete at lower altitudes. Therefore, training at high-altitude training help athletes gets more oxygen to their cells.
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What is the purpose of the cooling tower?
A. pumps cool water into the reactor
B. reduces heat pollution to the environment
C. cools down the electric generator
Answer:
id say c though im not sure
Explanation:
Cooling towers are primarily used for heating, ventilation, and air conditioning (HVAC) and industrial purposes.
Answer:
c
Explanation:
i had this on my test
What is the motion of the particles in this kind of wave?
A hand holds the left end of a set of waves. The waves themselves make a larger set of waves in the same direction as that of the smaller waves. A label Wave motion is above the series of waves and an arrow next to the label points right.
The particles will move up and down over large areas.
The particles will move up and down over small areas.
The particles will move side to side over small areas.
The particles will move side to side over large areas.
Answer:
D
Explanation:
The particles will move side to side over large areas.
Answer:
The particles will move side to side over large areas.
Explanation:
I REALLY NEED HELP can someone help me please I’ll mark you brainliest! :)
Answer:
A
Explanation:
What is the reducing agent in the following reaction
5Fe2+(aq) + MnO4-(aq) + 8H+(aq) → 5Fe3+(aq) + Mn2+(aq) + 4H2O(I)
A. MnO4-
B. Fe3+
C. Mn2+
D. Fe2+
E. H+
Answer: [tex]Fe^{2+}[/tex] is the reducing agent
Explanation:
Oxidation reaction : When there is an increase in oxidation state number.
Reduction reaction : when there is a decrease in oxidation state number.
[tex]5Fe^{2+}(aq)+MnO_4^-(aq)+8H^+(aq)\rightarrow 5Fe^{3+}(aq)+Mn^{2+}(aq) +4H_2O(l)[/tex]
Fe has undergone oxidation, as its oxidation state is changing from+2 to +3.
Mn has undergone reduction, as its oxidation state is changing from +7 to +2.
The chemical agent which itself get oxidized and reduce others is called reducing agent. [tex]Fe^{2+}[/tex] is a reducing agent.
The chemical agent which itself get reduced and oxidize others is called oxidizing agent. [tex]MnO_4^-[/tex] is an oxidizing agent.
.
If you ingest a chemical from lab, immediately drink plenty of milk, then contact your instructor and wait for his/her response.
a. True
b. False
Answer:
False
Explanation:
The correct answer would be false.
If a chemical is ingested while working in the lab, the correct thing to do would be to contact the lab instructor right away as eating or drinking of any kind is prohibited in the laboratory.
While drinking milk may help in some cases depending on the nature and amount of the chemical ingested, only the lab instructor has the technical know-how to analyze the situation and administer first aids. Milk has the capacity to act as a buffer in some cases pending the time the victim would be able to get adequate medical attention.
A solution of sulfuric acid (H2SO4, 25.00 mL) was titrated to completion with 34.55 mL of 0.1020 M sodium hydroxide. What was the concentration of the sulfuric acid
Answer:
0.0705 M
Explanation:
We'll begin by writing the balanced equation for the reaction. This is given below:
H₂SO₄ + 2NaOH —> Na₂SO₄ + 2H₂O
From the balanced equation above,
The mole ratio of the acid, H₂SO₄ (nA) = 1
The mole ratio of the base, NaOH (nB) = 2
Next, data obtained from the question. This include the following:
Volume of acid, H₂SO₄ (Va) = 25 mL
Volume of base, NaOH (Vb) = 34.55 mL
Molarity of base, NaOH (Mb) = 0.1020 M
Molarity of acid, H₂SO₄ (Ma) =?
The molarity of the acid, H₂SO₄ can be obtained as follow:
MaVa / MbVb = nA/nB
Ma × 25 / 0.1020 × 34.55 = 1/2
Ma × 25 / 3.5241 = 1/2
Cross multiply
Ma × 25 × 2 = 3.5241
Ma × 50 = 3.5241
Divide both side by 50
Ma = 3.5241 / 50
Ma = 0.0705 M
Therefore, the concentration of the acid, H₂SO₄ is 0.0705 M
Answer:
C=0.140964M
Explanation:
M1V1=M2V2
DATA
M1=?
M2=0.1020M
V1=25.00ML
V2=34.55ML
M*25.00ML=(0.1020M)*(34.55ML)
M*25.00ML=3.5241M*ML
M=3.5241M*ML/25.00ML
M=0.140964M
Therefore, concentration of sulfuric acif is 0.140964M
what is the answer i need help
so it is necessary to place the coefficient 2 in the front of HCL to balance the chemical equation to prove that
we have two CL and two H atoms in the products and one Cl and one H atom in the reactants so if we dont put 2 in front of HCL the chemical equation will not be balanced
how will we know that a chemical reaction happened if we cant see atoms??
we can do soo by noticing any colour change, or by the formation of an insoluble precipitate or by the evolution of a gas.
Which describes the number of protons in the atom of a particular element
Answer:
Atomic Number
Explanation:
The number of protons an atom has is unique to that element. The number of protons is noted as the atomic number for that element on the periodic table.
Which statements describe density? Check all that apply.
O Density is a chemical property of an object.
O The density of an object is constant.
O Density is a derived unit of measure.
D Density is the sum of the mass and volume of an object.
I The density of an object determines whether it will sink or fioat.
Answer:
2,3,5
Explanation:
Got correct on EDG
A block is pulled 0.90 m to the right in 2.5 s.
What is the block’s average speed to the nearest hundredth of a m/s?
The block’s average speed : 0.36 m/s
Further explanationDistance is the length traveled by an object within a certain of time .
Average speed = total distance/total amount of time ,
Can be formulated :
[tex]\tt avg.s(speed)=\dfrac{\Delta D}{\Delta t}[/tex]
ΔD= total distance
Δt= total time
A block is pulled 0.90 m to the right in 2.5 s :
ΔD= total distance = 0.9 m
Δt= total time = 2.5 s
The block’s average speed :
[tex]\tt avg.s=\dfrac{0.9}{2.5}=0.36~m/s[/tex]
what's the alkalinity of lemon?
Answer:
Hey mate here's your answer ⤵️
Lemon juice in its natural state is acidic with a pH of about 2, but once metabolized it actually becomes alkaline with a pH well above 7
Hope it was helpfulllHELP!!!
Which climate favors mechanical weathering?
dry limate
cold climate
warm climate
desert climate
Explanation:
cold climates hope this helps :)
Answer:
Cold climates
Explanation:
Warm climates favor chemical weathering. Cold climates favor mechanical weathering. Chemical reactions occur faster at higher temperatures.