Answer:
[tex]l=3.5*10^{-10}m[/tex]
Explanation:
From the question we are told that:
1st Energy [tex]E_1=12eV=4(3eV)[/tex]
2nd Energy [tex]E_2=27eV=9(3eV)[/tex]
3rd Energy [tex]E_3=48eV=16(3eV)[/tex]
Generally the equation for Energy E for electron in one dimensional box at ground state [tex]E_0[/tex] is mathematically given by
[tex]E_0=\frac{h}{8ml^2}[/tex]
[tex]E_0=\frac{h}{8ml^2}[/tex]
Therefore Length a is mathematically given as
[tex]l=\sqrt{\frac{h^2}{8mE_0} }[/tex]
[tex]l=\sqrt{\frac{(6.625*10^{-34})^2}{8(9.1*19^{-31}{(3eV(1.6*10^{-19}))}}[/tex]
[tex]l=3.5*10^{-10}m[/tex]
How is water used in society
Answer:
Water can be used for direct and indirect purposes. Direct purposes include bathing, drinking, and cooking, while examples of indirect purposes are the use of water in processing wood to make paper and in producing steel for automobiles. The bulk of the world's water use is for agriculture, industry, and electricity.
Explanation:
Answer:
water is used for drinking, bathing, cooking, agriculture etc
If aqueous solutions of Ba(OH)2 and HNO3 are mixed, what products are formed? Select one: a. BaN2(s) + H2O(l) b. Ba(NO3)2(aq) + H2O(l) c. Ba(s) + H2(g) + NO2(g) d. Ba2O(s) + NO2(g) + H2O(l) e. Ba3N2(s) + H2O(l)
Answer: Ba(NO3)2(aq) + H2O(l)
Explanation:
What is the molarity (molar concentration, unit = M) of K+ found in 200 mL 0.2 M K2HPO4 solution?
Answer:
0.4 M
Explanation:
The process that takes place in an aqueous K₂HPO₄ solution is:
K₂HPO₄ → 2K⁺ + HPO₄⁻²First we calculate how many K₂HPO₄ moles are there in 200 mL of a 0.2 M solution:
200 mL * 0.2 M = 40 mmol K₂HPO₄Then we convert K₂HPO₄ moles into K⁺ moles, using the stoichiometric coefficients of the reaction above:
40 mmol K₂HPO₄ * [tex]\frac{2mmolK^+}{1mmolK_2HPO_4}[/tex] = 80 mmol K⁺Finally we divide the number of K⁺ moles by the volume, to calculate the molarity:
80 mmol K⁺ / 200 mL = 0.4 MName (3) ways an animal can use energy from food?
Answer:
The food chain begins with the sun: plants get their energy by photosynthesizing sunlight into energy, and then herbivores eat those plants to get their energy. Carnivores who then eat the herbivores are getting that sunlight passed along from sun to plant to herbivore to carnivore.
Which solution is a homogeneous mixture?
sand and water
salt and water
salad dressing
soil
Answer:
soil
Explanation:
How are cells organized?
A: Organs
B: Organelles
C: Tissues
Answer:
tissues,organs, organelles
Is anyone good at chemistry if so can someone help me please ?
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So, what's shown here is the ion product of pure water: that is, the product of the concentrations of hydronium and hydroxide ions in pure water at 25 °C. By this relation, if you know the [H₃O⁺], you can calculate the [OH⁻], and vice-versa.
Since [H₃O⁺] × [OH⁻] = 1.0 × 10⁻¹⁴, [OH⁻] = (1.0 × 10⁻¹⁴)/[H₃O⁺].
Substituting the given [H₃O⁺] as 1.25 × 10⁻² M:
[OH⁻] = (1.0 × 10⁻¹⁴)/(1.25 × 10⁻² M) = 8.0 × 10⁻¹³ M.
d. What do all of the molecules in the table have in common?
Answer:
They all have a certain amount of protons electrons and neutrons.
Be sure to answer all parts.
Find the pH during the titration of 20.00 mL of 0.1000 M triethylamine, (CH3CH2)3N (Kb = 5.2 × 10−4), with 0.1000 M HCl solution after the following additions of titrant.
20.20 mL:
pH =
a.
Initial moles of (CH₃CH₂)₃N = (0.1000 mol/L) × (20.00/1000 L) = 0.002 mol
Moles of HCl added = (0.1000 mol/L) × (13.00/1000 L) = 0.0013 mol
Addition of 1 mole of HCl reacts with 1 mole of (CH₃CH₂)₃N to 1 mole of (CH₃CH₂)₃NH⁺.
After addition of 13.00 mL of HCl:
Moles of (CH₃CH₂)₃N left unreacted = (0.002 - 0.0013) mol = 0.0007 mol
Moles of (CH₃CH₂)₃NH⁺ produced = 0.0013 mol
Hence, [(CH₃CH₂)₃NH⁺]/[(CH₃CH₂)₃N] = 0.0013/0.0007 = 13/7
Consider the dissociation of (CH₃CH₂)₃N:
(CH₃CH₂)₃N(aq) + H₂O(l) ⇌ (CH₃CH₂)₃NH⁺(aq) + OH⁻(aq) …… Kb = 5.2 × 10⁻⁴
Henderson-Hasselbalch equation:
pOH = pKb + log([(CH₃CH₂)₃NH⁺]/[(CH₃CH₂)₃N])
pOH = -log(5.2 × 10⁻⁴) + log(13/7) = 3.55
pH = pKw - pOH = 14.00 - 3.55 = 10.45
====
b.
Initial moles of (CH₃CH₂)₃N = 0.002 mol
Moles of HCl added = (0.1000 mol/L) × (20.80/1000 L) = 0.00208 mol
HCl is in excess.
Moles of HCl left unreacted = (0.00208 - 0.002) mol = 0.00008 mol
Volume of the final solution = (20.00 + 20.80) mL = 40.8 mL = 0.0408 L
In the final solution:
[H₃O⁺] = [HCl] = (0.00008 mol) / (0.0408 L) = 0.00196
pH = -log[H₃O⁺] = -log(0.00196) = 2.71
====
c.
Initial moles of (CH₃CH₂)₃N = 0.002 mol
Moles of HCl added = (0.1000 mol/L) × (29.00/1000 L) = 0.0029 mol
HCl is in excess.
Moles of HCl left unreacted = (0.0029 - 0.002) mol = 0.0009 mol
Volume of the final solution = (20.00 + 29.00) mL = 49 mL = 0.049 L
In the final solution:
[H₃O⁺] = [HCl] = (0.0009 mol) / (0.049 L) = 0.0184
pH = -log[H₃O⁺] = -log(0.0184) = 1.74
1.
Why are kilometers not a good unit of measurement in space?
T.
2.
What distance measurement unit is used for objects within our solar system?
astronomical
units
3.
How many kilometers are in one astronomical unit?
4.
What distance measurement unit is used for objects outside of our solar
system?
_light
year!
5.
How many kilometers are in one light-year? I
How far away is the nearest star to Earth other than our Sun?
6.
7.
How far away is the center of the Milky Way Galaxy from Earth?
8.
What is the diameter of the Milky Way Galaxy?
help now im not trying to fail
Answer:
i cant see the whats in the picture
show by means of equations how to separate mixture of benzoic acid and phenol
Just dissolve all three compounds in an organic solvent which not miscible with water (those two I have mentioned) in separatory funnel. Use aqueous sodium bicarbonate first to extract. If you use sodium hydroxide, both phenol and benzoic acid will be extracted as both can react with hydroxide
Calculate the heat energy released when 21.1 g of liquid mercury at 25.00 °C is converted to solid mercury at its melting point.
Constants for mercury at 1 atm
heat capacity of Hg(l) 28.0 J/(mol⋅K)
melting point 234.32 K
enthalpy of fusion 2.29 kJ/mol
Is anyone good at chemistry if so can someone help me please ?
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So, litmus paper is a qualitative tool for assessing the acidity or basicity of a substance (usually a solution). In general, blue litmus turns red in the presence of an acid, and red litmus turns blue in the presence of a base. They can't really tell you much more than that.
The solutions that are most likely acids are those that turn blue litmus red and do not evoke a color change in red litmus. A solution that turns red litmus blue or does not evoke a color change in blue litmus is likely not an acid. Using these criteria, solutions 4 and 7 are most likely acids since they both turn blue litmus red (and they cause no color change in red litmus).
The correct answer choice would thus be D.
a freshwater stream flows into the ocean as shown in the diagram which statement correctly describes how the stream affects these salinity of the ocean
A- salinity increases because the stream adds salt to the ocean.
B- salinity decreases because the stream adds freshwater to the ocean
C- salinity increases because of stream adds freshwater to the ocean
D- salinity Remains the Same because the stream adds freshwater to the ocean
In a simple food chain, a frog eats insects and a snake eats the frog. The primary role of the frog in the food chain is?
Answer:
It is clear from the above food chain that the grass occupies the first topic level which consists of producers. The second tropic level consist of primary consumers which is Insect. And the Frog assign the Third tropic level of food chain consisting of secondary consumers.Explanation:
List 3 technologies that have made jobs easier.
Answer:
-security hardware
- artificial intelligence
wifi, internet, phones, voice assistants, drones.
4. How many atoms are in 1.73 moles of copper(I) oxide?
wish in new Explanation:
difference between vegetative and reproductive part
Answer:
The vegetative parts includes the roots, stems,leaves and the reproductive parts include flowers. ... The vegetative parts can reproduce new plants by the process of vegetative propagation but the reproductive parts cannot produce new plants directly instead they produce precursor of new plants that are seeds or fruits.
What is the reducing agent in the following reaction?
2 Br−(aq) + H2O2(aq) + 2 H+(aq) → Br2(aq) + 2 H2O(l)
Answer:
the reducing agent is Bromine
The oxidation state of an element is calculated by subtracting and the total sum of oxidation states of all the individual atom (excluding the one that has to be calculated) from total charge on the molecule. Bromine is the reducing agent in the following reaction.
What is oxidation state?Oxidation state of an element is a number that is assigned to an element in a molecule that represents the number of electron gained or lost during the formation of that molecule or compound.
The ionic equation is given as
2 Br⁻(aq) + H[tex]_2[/tex]O[tex]_2[/tex](aq) + 2 H⁺(aq) → Br[tex]_2[/tex](aq) + 2 H[tex]_2[/tex]O(l)
The oxidation state of bromine on reactant side is -1 while on product side it is 0 so, oxidation state of bromine has increased by 1 so, bromine is oxidized. If it is oxidized that means it must have reduced someone. So, bromine is acting as a reducing agent.
Therefore, bromine is the reducing agent in the given reaction.
To learn more about Oxidation state, here:
https://brainly.com/question/11313964
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plz hleeeeeeeeeep meeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
My teacher laid this much out for us but I don’t know how to get the products in each one.
Answer:dang
Explanation:
What is the molar mass of AlCl3
Answer:
133.34 g/moles
Explanation:
but to make life easy it could be 133.4 g/ moles as well
I need help with this science problem
Answer:
I'm pretty sure its D
Explanation:
It says the best that explains. D states that when it has less energy that it the molecules will collide. And they would to make a liquid. So thats why its D.
What are 2 comparisons between organisms and music?
Help me fast I put 98 points pls help me no links I am serious.
3rd repost
Joaquin's doctor tested Joaquin's reflexes by tapping his knee. The doctor
explained to Joaquin that the tapping sends a signal to his spinal cord. The
spinal cord then sends a signal to the muscle in Joaquin's thigh, and his leg
moves. Which of the following body systems is involved in this process?
A. Respiratory system
B. Nervous system
C. Skeletal system
D. Digestive system
Answer: Skeletal System
Explanation: Sense It's Sending up a signal up Joaquin's spinel cord It must be traveling threw his skeletal system
Answer:
its the nervous system because by tapping the knee, it will send a nerve down the neuron, through the mylein sheath and through the axon terminals to the receptors, which will recieve the nerve's signal and send it to the brain through the spinal cord in simple terms.
2 C.H. (g) + 190, (g) → 1200, (g) + 147,0 (8)
Answer:
please your question is not understandable
PLEASE HELPP WILL MARK BRAINLEST!!!!
Answer:
B i think
Explanation:
A student prepares a aqueous solution of butanoic acid . Calculate the fraction of butanoic acid that is in the dissociated form in his solution. Express your answer as a percentage. You will probably find some useful data in the ALEKS Data resource.
Answer:
15.4%
Explanation:
If Ka = 0.54 mM = 1.51x10⁻⁵
Then;
C₄H₈O₂ --------> C₄H₇O₂⁻ + H⁺
I 0.54x10⁻³ 0 0
E 0.54x10⁻³(1-x) 0.54x10⁻³x 0.54x10⁻³x
Recall that x is the percentage degree of dissociation
From the ICE table;
Ka = [C₄H₇O₂⁻] [ H⁺]/[C₄H₈O₂]
1.51x10⁻⁵=(0.54x10⁻³x) (0.54x10⁻³x)/ 0.54x10⁻³(1-x)
1.51x10⁻⁵ = 0.54x10⁻³x^2/1-x
1.51x10⁻⁵(1-x) = 0.54x10⁻³x^2
1.51x10⁻⁵ - 1.51x10⁻⁵x = 0.54x10⁻³x^2
Hence;
0.54x10⁻³x^2 + 1.51x10⁻⁵x - 1.51x10⁻⁵=0
x^2 + 0.028x - 0.028 = 0
Solving the quadratic equation here;
x = 0.154 or −0.182
Ignoring the negative result, x = 0.154
Hence, fraction of butanoic acid that is in the dissociated form in this solution = 15.4%
The analysis in this experiment assumes that CO2 is an ideal gas. Select the answer below that best explains if CO2 is an ideal gas and why. Group of answer choices CO2 is an ideal gas; this is because it is polar. CO2 is not an ideal gas; while it is nonpolar, the molecules do attract and repel each other, they also take up space- two characteristics that an ideal gas does not have. CO2 is not an ideal gas; it is polar, the molecules strongly attract and repel each other, they also take up space- two characteristics that an ideal gas does not have. CO2 is an ideal gas; this is because it is nonpolar.
