The correct decreasing order of the basic strength of amines in an aqueous solution is (C2H5)3N > (C2H5)2NH > C2H5NH2.
What do you mean by a chemical's fundamental strength?
The ability of a chemical to share electrons with nearby atoms is referred to as the chemical's fundamental strength.
The nitrogen atom becomes electron-rich as a result of the lone pairs. The +I effect is the second component.
Because the three benzene rings are connected to nitrogen and stearic hindrance forms as a result, nitrogen is unable to donate its lone pair to the rings, giving (C2H5)3N the highest degree of +I effect out of all the supplied amines. Lone pairs are so accessible for the incoming atoms.
As a result, (C2H5)3N > (C2H5)2NH > C2H5NH2 is the order.
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Question 11
A material whose particle composition allows heat and electricity to pass through it easily are described as having a high
OA) conductivity
O B) density
OC) hardness
OD) weight
Answer:
Coductivity
Explanation:
Because heat conducts to them!
A student is studying how far room temperature water could squirt i meant would squirt out of a plastic milk carton when 4mm holes or punch at different heights from the bottom of the container
Independent variable: Hole height
Water squirting distance is a dependent variable.
The size of the perforations in the milk carton is constant.
During experiments, the value of the independent variable is frequently changed, and the impact of the change on the dependent variable is then measured.
The variable that is actually being measured during an experiment is known as the dependent variable. Changes in the independent variable's values have an impact on the dependent variable's value.
Variables that don't vary over the course of an experiment are known as constants.
Hence, in the illustration:
Independent variable: the height of holes on the milk carton
Dependent variable: distance of squirting water
Constant: the size of holes punched into the milk carton
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COMPLETE QUESTION:
Directions: Read the given scenarios below. Identify each required component for each scenario.
Scenario 1:
A student is studying how far room-temperature water would squirt out of a plastic milk carton when 4 mm holes are punched at different heights from the bottom of the container. Describe which are the independent and dependent variables as well as indicate the constants involved within the experiment and why those are the constants.
Independent Variable:
Dependent Variable:
Constants:
caco3 is added to a 250 ml volumetric flask with 50 ml of water. hcl is added drop-wise until effervescence is not longer observed, and then diluted to the mark. what is the molarity of caco3 in the flask?
The concentration of the calcium ions in the solution is obtained as 0.013 M
What is the molarity of the solution?Now we have to find the concentration of the calcium ions, we have to look at the question. We can see from the question that;
Mass of calcium carbonate = 0.3205g
Number of moles of calcium carbonate = 0.3205g /100 g/mol = 0.003205 moles
Number of moles calcium ions = 0.003205 moles
The question here is that we ought to find the concentration of the EDTA solution and that is what we need to find in the spaces that follow in this answer as we have here.
Concentration of the calcium ions in the solution = 0.003205 moles/250 * 10^-3
= 0.013 M
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Missing parts;
A 0.3205g sample of CaCO3 was dissolved in HCl and the resulting solution diluted to 250.ml in a volumetric flask. A 25 mL sample of the solution required 18.75mL of EDTA solution for titration to the Eriochrome Black T end point. What is the concentration of Ca2+ (mol/L) in the 250.0ml of CaCl2 solution?
what is the percent ionization of a 0.427 m solution of ethylamine (ch3ch2nh2) in 0.113 m calcium hydroxide?
Percentage ionization of ethylamine is 4%.
What is the percent ionization?The portion of the original chemical that has undergone ionization is the percent ionized. So, we contrast the ion's concentration in solution with the neutral species' initial concentration.
Given,
Concentration of ethylamine =0.427 m,
Concentration of calcium hydroxide = 0.113 m,
As ethylamine(CH₃CH₂NH₂) is a weak base, it will not in equilibrium,
CH₃CH₂NH₂ ⇆ CH₃CH₂NH₃⁺ + OH⁻
also from CaOH₂ ; OH⁻ ions are coming which will show common ion effect
CaOH₂ → Ca⁺ + 2OH⁻
0.113 - -
- 0.113 0.113×2
=0.226
Now, CH₃CH₂NH₂ ⇆ CH₃CH₂NH₃⁺ + OH⁻
c - cα cα + 0.226 ≈ 0.226
Kₐ = [ OH⁻] [CH₃CH₂NH₃⁺]/[CH₃CH₂NH₃⁺]
=[tex]\frac{c\alpha \times 0.226}{c-c\alpha}\\[/tex]
= [tex]\frac{\alpha\times 0.226 }{c- c\alpha} \\[/tex]
0.01= α ×0.226
α= [tex]\frac{0.01}{0.226}[/tex]
α=0.44
now percentage ionization = 4%.
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Calculate the theoretical yield of acetylsalicylic acid if excess acetic anhdride and 3.50 grams of salicylic are used in the reaction:
When multiplied by salicylic acid's molecular weight of 1 80.158, it will be equal or smooth. If we compute it now, we will see that the mask, or theoretical yield, is equal to $4.57 million.
Acetylsalicylic AcidAspirin, also known as acetylsalicylic acid (ASA), works by permanently blocking the platelet cyclooxygenase (COX) enzyme, which in turn prevents the production of the platelet thromboxane A2 (TXA-2). A medication called aspirin (acetylsalicylic acid) is used to treat pain or inflammation1. 3 As a non-steroidal anti-inflammatory medicine, it is categorized (NSAID). Pain that is mild to moderate can be treated with aspirin. However, safety concerns regarding the danger of bleeding as well as the possibility of developing a rare but serious liver and brain condition, most commonly in youngsters (Reye's syndrome), should be taken into account.To learn more about Acetylsalicylic Acid refer:
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What is an ionic compound?
Answer:
Ionic compounds are neutral compounds made up of positively charged ions called cations and negatively charged ions called anions. For binary ionic compounds (ionic compounds that contain only two types of elements), the compounds are named by writing the name of the cation first followed by the name of the anion
Explanation:
hope this helps!!
The hydrolysis of _____ is an exergonic reaction that drives many endergonic reactions in a cell.
The hydrolysis of ATP into ADP and inorganic phosphate is an exergonic reaction that drives many endergonic reactions in a cell.
ATP hydrolysis is a form of reaction, right?Adenosine triphosphate (ATP) is a molecule that can store chemical energy in high-energy phosphoanhydride bonds. These bonds can be split to release chemical energy, for example in muscles. This process is known as ATP hydrolysis.
ADP has a higher entropy than ATP, which is a measure of chaos. The reaction therefore happens spontaneously because it desires to be at a higher entropy level owing to thermodynamics. Additionally, ATP has a greater Gibbs free energy value than ADP.
In order to proceed, an endergonic reaction needs free energy. Photosynthesis is an instance of an endergonic process of biological importance.
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You heat 3.970 g of a mixture of Fe3O4 and FeO to form 4.195 g Fe2O3. The mass percent of FeO originally in the mixture was:
FeO + Fe3O3 + 1/2O2 → 2Fe203
→ Molar mass of Fe2o3 = 159.69g/mol
→ Molar mass of FeO = 71.84g/mol
→Molar mass Fe3o4 = 231.53g/mol
1. first of all , let consider the amount of Fe in Fe2O3
Atomic Mass of Fe = 58.845 g/mol
Percentage of Fe in Fe2)3 = ( 2 x mass of Fe / Molar Mass Fe203) = 2x(55.845) /159.69g/mol
= 0.6994 * 100 = 69.94 %
2. Mass of Fe in 4.195g of Fe2O3 will then be :
0.06994 * 4.195g = 2.934 g
3.(i) percentage of Fe in FeO = (55.845 / 71.84g/mol ) = 0.77735* 100 =77.735
(ii)percentage of Fe in Fe3O4 = (3x 55.845)/231.53g/mol= 0.72359*100 =72.359
(remember , we only have molar mass of FeO as well as molar mass for Fe3O4 , we do not have their mass)
4. so we will say; let x be the mass for Fe3O4
and ; let y be the mass of FeO
However , the mass of FeO and FeO3O4 must equal 3.970 as given in the question.
meaning x +y = 3.970; therefore x = (3.970-y)
But, we also know from the above percentage calculations; that :
• Mass of Fe in FeO = 0.77735 = 0.77735 ,y
,• Mass of Fe in Fe3O4 = 0.72359 = 0.72359,x
5. now lets solve for x and y by equating the above:
0.77735 y + 0.72359x =2.934 g
0.77735 y + 0.72359(3.970-y) =2.934 g
solving for y; you will get :
0.07735y + 2.8726 -0.72359y = 2.934
0.05385y = 0.061347
therefore y = 1.142 g = mass of FeO
Finally :
Mass percentage= (Mass FeO /given mass of the mixture ) * 100
= 1.142g/3.970 *100
= 28. 7 %
need help please answer
Answer:
True
Explanation:
The answer is True if it's wrong forgive me if its right heart it.
if a mixture consisting of 10 % cyclohexane and 90 % toluene were distilled in a fractional distillation apparatus having 2 theoretical plates, what would the composition of cyclohexane be in the first drop of distillate? %
The first drop of distillate would contain 33 mol% of toluene and 67 mol% of cyclohexane. We can reach this conclusion by consulting the boiling point composition curve attached.
When analyzing the composition of the vapor phase and the liquid phase during the distillation of two liquids with different boiling points, it is necessary to use the boiling point composition curve.
We begin on the right by finding the point on the curve that corresponds to our initial mixture composition (90 mol% toluene, 10 mol% cyclohexane). We then move to the left, to find the composition of the vapor phase. This will be the composition of the distillate after one theoretical plate (approximately 67 mol% toluene, 33 mol% cyclohexane). Because we have two theoretical plates, we repeat the process, but now the composition of the liquid phase is the same as the vapor phase because we are now basically distilling our first distillate for the second time.
So we again move to the left to find the composition of the vapor phase, which will be the composition of our distillate after two theoretical plates: 33 mol% toluene and 67 mol% cyclohexane.
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The relationship between the energy of a photon and the frequency of light was determined by Ernst Planck (1858 - 1947). Here is the equation he discovered E = hf. Because photons of light have wave-like properties this equation may also be represented using the speed of light and wavelength, E = hc/λ.
Where h is Planck’s constant = 6.63 x 10-34 J*s)
c is the speed of light = 3.00x108 m/s
f is the frequency of the photon (in cycles/sec or s-1)
λ is the wavelength of light (in meters)
1. Show how you calculate the energy of light that has a frequency of f = 4.0 x 10^14 s^-1.
2. Use the information above to determine the wavelength of a photon of light that has the same energy
The energy of a photon can be calculated by multiplying Planck's constant by the frequency of the light.
According to this question, the relationship between the energy of a photon and the frequency of light was determined by Ernst Planck. He proposed a equation as follows:
E = hf
Where;
E = energy in joulesh = Planck's constant (6.626 × 10-³⁴J/s)f = frequency (Hz)The energy of a frequency 4.0 × 10¹⁴ Hz can be calculated as follows:
E = 6.626 × 10-³⁴ × 4 × 10¹⁴
E = 2.65 × 10-¹⁹J
λ = hc/E
λ = 6.626 × 10-³⁴ × 3 × 10⁸/2.65 × 10-¹⁹
λ = 1.988 × 10-²⁵/2.65 × 10-¹⁹
λ = 7.5 × 10-⁷m
Therefore, 7.5 × 10-⁷m is the wavelength of the photon.
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Mass of empty Erlenmeyer Flask (g) 30.46 g Mass of flask 100 ml 10% vinegar (g) 85.56 g Mass of flask 100 ml NaOH (g) 90.23 g Mass of flask after mixing the NaOH with 10% vinegar (g) 175.79 g Mass of the flask after the reaction (g) 145.33 g Temperature of the solution before it is mixed 21.9oC Temperature of the solution after it is mixed 23.1oC 1. Find the combined mass of the two reactions that have taken place. 2. Calculate the combined mass of the contents of the flasks after the reaction has taken place. 3. Finally, calculate the percent deviation within the lab. If the percent deviation was not 0%, what do you think might have happened in the lab that caused it to not be zero? (hint: remember, matter cannot be destroyed).
The combined mass of the two reactions that have taken place is 145.33 g.
The combined mass of the contents of the flasks after the reaction has taken place is 114.87 g.
The percent deviation is 20.9 % and is not zero because some products escaped as gas.
What is the law of conservation of mass?The law of conservation of mass states that matter cannot be created nor destroyed.
This means that for a given chemical reaction, the total mass of the reactants will equal the total mass of the products.
The masses in the reaction are:
Mass of empty Erlenmeyer Flask (g) 30.46 g
Mass of the combined reactants = (175.79 - 30.46) g
Mass of the combined reactants = 145.33 g
Mass of the contents of the flask after the reaction has taken place = 145.33 - 30.46) g
mass of the contents after the reaction = 114.87 g
Percent deviation = (145.33 - 114.87) / 145.33 * 100%
Percent deviation = 20.9 %
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let's consider that ethyl acetate is the ideal solvent for this tlc experiment. what might have happened to the spots if you had used t-butyl methyl ether as the eluent instead of ethyl acetate.
The spots will remain towards the bottom of the TLC plate in the TLC experiment if the eluent is changed from ethyl acetate to t-butyl methyl ether.
The spots will remain at the bottom of the TLC plate because t-butyl methyl ether is less polar and cannot overcome attractions of sample to adsorbent.
TLC experiment concept is simple. In TLC, adsorbent is silica which is highly polar. Then the eluent we can use as in different percentage of ethyl acetate & ether solution depending upon the polarity of given products.
As we know that polar molecules strongly bind with other polar molecules, ethyl acetate and silica gel are highly polar, the solvent ethyl acetate overcomes the strong bonding between the spotted product and adsorbent and takes the spot with the solvent upto the top.
If in this TLC experiment, instead of ethyl acetate, t-Butyl methyl ether is used, which is a highly non-polar or less polar solvent, it does not overcome the bonding since polar spots don't have greater binding affinity towards this non-polar ether solvent, therefore, the spots will remain tightly bonded with silica on TLC plate and spots will remain at the bottom of the TLC plate.
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The table gives the numbers of protons, neutrons and electrons in some atoms and ions of elements. The letters used in the table are not the chemical symbols of the elements.
Explanation:
a. i. R and Z (same number of protons but different number of neutrons therefore are isotopes of the same element).
ii. Q (has more portons than electrons).
iii. X (has more electrons than protons).
iv. L (mass number = protons + neutrons).
v. M (belongs to group 1 alkali metals which are of very reactive metals).
b. 12 (atomic number= number of protons).
c. 7 (X has 9 electrons before ionisation, therefore 7 electrons in the outer most shell).
Q (is also from ionisation reaction).
hope it helps :)
A. (i). Two identical atoms with the letters Q and Z each contain 17 protons.
ii. Protons outnumber electrons in a positive ion. R, which has 17 protons and 17 electrons, is the only atom or ion that has more protons than electrons. It removes an electron to form a positive ion with a charge of +1: R+.
iii. In a negative ion, the number of protons is more than the number of electrons. J has 16 electrons and 16 protons, making it the only atom or ion with more electrons than protons. It becomes a negative ion with a charge of -1, or J-, by the addition of one electron.
iv. Such an atom or ion has the letter M and has 11 protons and 12 neutrons. It adds a proton to form an atom with a mass number of 20: N with 12 protons and 8 neutrons.
v. Group 1 of the periodic table consists of metals that are extremely reactive. L, an atom in group 1 with 10 protons, is the only one in the table to have this characteristic.
What is an Atom?The fundamental building block of matter, an atom, nevertheless has the characteristics of an element. It consists of a small, compact nucleus with positively charged protons and electrically neutral neutrons surrounded by orbitals of negatively charged electrons.
For the above example,
(b) An atom with an atomic number of 12 has 12 electrons because an atom has exactly the same number of protons in the neutral state as electrons.
(C)
(i) X has exactly 11 protons, the same number of protons as the atom or ion M has. Group 1 of the periodic table, commonly known as the alkali metals, consists of elements with 11 protons.
(ii) An alkali metal is another atom that interacts in the same way as the substance from which ion X is made. According to the table, the only atom in group 1 is L, which has 10 protons. However it lacks the 11 protons of the alkali metals mentioned above
Therefore, two identical atoms with the letters Q and Z each contain 17 protons.
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A certain red light has a wavelength of 680 nm.
a. What is the frequency of the light?
A certain red light has a wavelength of 680 nm. then, The frequency of the light is 4.4×10^14 s^-1 .
Given,
A certain red light had a wavelength = 680nm
frequency is given by,
f =c/λ
where, f = frequency
c = speed of light = 3×10^8 m/s
λ = wavelength = 680nm
f = (3×10^8 ) /(680× 10^-9 )
f = 0.0044×10^17 = 4.4×10^14 s^-1
Hence, the frequency of the light is 4.4×10^14 s^-1 .
What is wavelength?The distance between the two crests or troughs of the light wave is known as the wavelength of light. Using the Greek letter lambda (), it is identified. As a result, wavelength refers to the separation between one wave's crest or dip and the following wave.
The formula for wavelength is given by,
wavelength= speed of light /frequency
What is frequency?According to the definition of frequency, it is the quantity of full wave cycles that pass a spot in a unit of time.
Hertz is the SI unit for frequency (Hz).
The number of full oscillations that any wave element makes in one unit of time is the frequency of a sinusoidal wave.
Frequency is in periodic motion; after going through a number of different situations or postures and then returning to its initial place, it has completed one cycle.
The reciprocal of a wave's period is equal to the wave's frequency.
The frequency mathematical expression is:
frequency = speed of light / wavelength
The length of time it takes for any string element to complete an oscillation is known as a wave's oscillation period.
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What is the atomic mass of hafnium if, out of every 100 atoms, 5 have a mass of 176, 19 have a mass of 177, 27 have a mass of 178, 14 have a mass of 179, and 35 have a mass of 180. 0?.
The atomic mass of hafnium is 178.55 amu based on the mass of the given isotopes.
To determine the average atomic mass of hafnium, we first determine the mass fractions of the isotopes as follows;
m(1) = 5 ÷ 100 = 0.05
m(2) = 19 ÷ 100 = 0.19
m(3) = 27 ÷ 100 = 0.27
m(4) = 14 ÷ 100 = 0.14
m(5) = 35 ÷ 100 = 0.35
Now the average atomic mass of hafnium can be calculated by the addition of the products of the mass fractions of the isotopes and their respective atomic masses.
Average atomic mass = [m(1) × 176] + [m(2) × 177] + [m(3) × 178] + [m(4) × 179] + [m(5) × 180]
Average atomic mass = (0.05 × 176) + (0.19 × 177) + (0.27 × 178) + (0.14 × 179) + (0.35 + 180)
Average atomic mass = 8.8 + 33.63 + 48.06 + 25.06 + 63
Average atomic mass = 178.55
Hence the average atomic mass of Hafnium is calculated to be 178.55 amu.
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How much heat is needed to raise the temperature of 10 grams of liquid water from 25°C to 50°C?
In which pair of elements are the chemical properties of the elements most similar? Explain your reasoning.
a. sodium and chlorine
b. nitrogen and phosphorus
c. boron and oxygen
Answer:
b. nitrogen and phosphorus
Explanation:
Elements in the same column of the Periodic Table have similar chemical properties. Both N and P are in the same column.
PLEASE HELP ASAP!!!!! (Show work and explanation please)
Suppose 200.0 g of ice absorb 1255.0 J of heat. What is the corresponding temperature change? Specific heat capacity of ice is 2.1 J/gC.
the answer is 6.0°C that is the solution
what mass of sodium chloride would need to be added to the blood to bring the sodium ion concentration up to 0.135 m m , assuming no change in blood volume?
7.89 g of NaCl is required to bring sodium ion concentration to 0.135 m.
Given:
The molality of NaCl in the given volume of blood=0.135 mol/ kg
1 mol of NaCl contains 1 mol of sodium ion.
Thus, 0.135 mol of sodium chloride is needed to give out 0.135 moles of sodium ion.
Therefore, the mass of sodium chloride needed=moles x molar mass=0.135 mol x 58.44 g/mo
l=7.89 g
What is molality?
The molality (m) is defined as the amount of solute (in moles) present in 1 kg solvent. It is calculated by dividing the moles of solute by the mass of the solvent (in kg). For example, a solution with a molality of 1 mol/kg is often described as 1 molal or 1 m.
Hence, 7.89g of NaCl would be needed.
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Raquel would like to describe the observable properties of water. What properties can she use?
A Colorless and rough
B Colorless and smooth
C Smooth and rough
D Soft and smooth
HELP ASAP
Answer:
b
Explanation:
water is generally transparent and smooth to the touch unless it is frozen, then it is rough
Compare the arrangements of the molecules of a solid, liquid,
and gas by illustrating them in the boxes below.
(I’VE BEEN STUCK FOR 3 DAYS)
The arrangements of the molecules of a solid, liquid and gas as follows
1. Solid: In this state of matter, the particles are closely bonded to each other. This means that they are closely packed in a system and the arrangement is regular. The intermolecular space between the particles is minimum.
2. Liquid: In this state of matter, the particles are not so closely packed. The arrangement between the particles is not regular. The intermolecular spacing between the particles is more than solid but less than gaseous state.
3. Gases: In this state of matter, the particles are very far away from each other and the arrangement is not regular. The intermolecular spacing between the particles is very much in case of gases.
What are the Three States of Matter?The solid, liquid, and gaseous phases of matter are the three basic states of matter.
Every item we encounter every day—from ice cream to chairs to water is composed of matter. Based on intermolecular forces and the arrangement of the particles, matter can be divided into distinct states such as solid, liquid, and gas. By altering specific environmental variables, these three types of matter can change their state of matter (increasing or decreasing pressure and temperature, for instance). For instance, raising the temperature will cause ice to melt from a solid state.
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In what ways does the element hydrogen behave like elements from group 1 and sometimes like elements from group 17? Make an argument for which group you think hydrogen should be placed in.
It mimics alkali metals in several of its characteristics, such as its ease in forming cations.
What category does hydrogen fall under?Chemical element hydrogen has the atomic number 1 and the letter H after it. It is a diatomic gas with the chemical formula H2 that is colorless, odorless, nonmetallic, tasteless, and extremely combustible.
Because it shares some characteristics with alkali metals, such as the ability to form cations easily, hydrogen can be placed in both groups 1 and 17 of the periodic table. However, because it also shares characteristics with halogens, such as the ability to form H2, hydrogen can also be placed in group 17. While hydrogen can take electrons, it also has a propensity to reject them in order to maintain stability. It is the family's tiniest member.
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what happens to matter and energy when a substance combusts
Nothing is destroyed by burning or other modifications to matter. Before and after changes always occur, the mass of the substance remains constant. According to the principle of conservation of mass, matter cannot be created or destroyed.
Where does matter go when burned?Exothermic reactions characterize all combustion processes. A substance burns when it reacts with oxygen in a combustion reaction. Burning materials often release energy in the form of heat and light.In the chemical process of combustion, an object quickly combines with oxygen to produce heat. The original substance is referred to as the fuel, and the oxygen's source as the oxidizer.Nothing is destroyed by burning or other modifications to matter. Before and after changes always occur, the mass of the substance remains constant. According to the principle of conservation of mass, matter cannot be created or destroyed.combustion is a chemical reaction that often involves the presence of oxygen and produces heat and light in the form of flames.To learn more about : Combustion
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Which phase is a good description of kinetic energy?(1 point)
conserved energy
energy from the sun
energy of motion
stored energy
Answer: Energy of motion :)
Answer: the answer to your question is the energy of motion
Explanation:
What is a planet's orbit?
Answer:
An orbit is a regular, repeating path that one object in space takes around another one.
ammonia, nh3, is used as a refrigerant. at its boiling point of –33 c, the standard enthalpy of vaporization of ammonia is 23.3 kj/mol. how much heat is released when 50.0 g of ammonia is condensed at –33 c?
- 68.385 kJ amount of heat will be released when 50.0 g of ammonia is condensed at –33 °C.
The standard enthalpy of vaporization of ammonia = 23.3 kJ/mol
This means the energy required to vaporize one mole of ammonia at its boiling point = -33 °C
Let's calculate the heat released when 50.0 g of ammonia is condensed at -33 °C.
The heat released is the opposite of the enthalpy of vaporization i.e Q = -23.3 kJ/mol (-ve sign indicates the reaction is exothermic)
We are given
Mass of ammonia m(NH₃) = 50.0 g
Number of moles of ammonia n(NH₃) = 50.0 g ÷ 17.031 g/mol.
n(NH₃) = 2.935 mol
The amount of heat released when 2.935 mol moles condensed at -33 °C
Q = Hv x n(NH₃).
Q = 23.3 kJ/mol x 2.935 mol
Q = - 68.385 kJ
Thus, -68.4 kJ amount of heat is released when 50 g of ammonia is condensed at -33 °C, where negative sign signifies release of heat.
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In the titration of acetic acid and naoh, the use of the color indicator requires that excess base be added in order to detect the endpoint. Will this cause the calculated and reported mass percent of acetic acid in vinegar to be too high or too low? explain.
When excess base is added in order to detect the end point, then it will cause the calculated and reported mass percent of acetic acid in vinegar to be too high.
A titration is a method of quantitative chemical analysis, in which the concentration of an unknown solution called the analyte, by using a solution of known concentration, called the titrant.
The titrant solution from the burette is added slowly to the analyte solution, in the conical flask, in order to determine the end point of the titration. The end point is indicated by a change in color of the solution in the presence of an indicator.
An acid-base titration involves a neutralization reaction between an acid and a base.
As given in the question, the concentration of acetic acid solution is being determined by sodium hydroxide (NaOH) solution of known concentration.
Therefore, Sodium hydroxide is the titrant and is taken in the burette. Whereas, acetic acid is the analyte which is taken in the conical flask and two- three drops of the indicator is added to it.
Example of the indicator that can be used in an acid-base titration is phenolphthalein. Phenolphthalein is colorless in acidic medium and pink in basic medium.
Initially, the analyte acetic acid solution will be colorless. Since, phenolphthalein is colorless in acidic medium.
Then, NaOH solution will be slowly added from the burette to the acetic acid solution. On reaching the end point, a slight excess amount of the NaOH base is added from the burette.
The excess amount of NaOH makes the solution in the conical flask basic. Therefore, changing the color of the solution, from colorless to pink. Since, phenolphthalein is pink in basic medium.
This excess amount of the titrant i.e. NaOH solution added, increases the volume of the NaOH solution being used in the titration.
Since, acetic acid is directly proportional to volume of NaOH or any base used, then even a slight increase in the volume of the NaOH solution, increases the concentration or molarity of acetic acid
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balance the following equation and express the rate in terms of the change in concentration with time for each substance: no(g) o2(g) n2o3 (g) when n2o3 is forming at 0.527 m/s, at what rate is no decreasing? enter a positive number to 3 decimal places.
The balanced reaction equation for this redox reaction is:
4NO(g) + O₂(g) → 2N₂O₃(g)
The rate of [NO] decreasing is 1.054 M/s.
This is a redox reaction, so to balance it, we need to identify which elements change their oxidation state. Obviously, nitrogen is oxidized from +2 (N²⁺O²⁻) to +3 (N⁺³₂O²⁻₃), and oxygen is reduced from 0 (O⁰₂) to -2.
N²⁺ → N⁺³ + e⁻
O⁰₂ + 4e⁻ → 2O²⁻
In order for the number of electrons released and taken to be the same, we need to multiply the number of nitrogens by 4:
4N²⁺ → 4N⁺³ + 4e⁻
O⁰₂ + 4e⁻ → 2O²⁻
We can now apply these numbers to the reaction equation:
4NO(g) + O₂(g) → 2N₂O₃(g)
With the balanced reaction equation, we can see that 4 moles of NO produce 2 moles of N₂O₃. So if 0.527 M were produced in a single second, the rate of NO decreasing would be 2 * 0.527 M = 1.054 M/s.
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3. Why is it important for other variables in an experiment to be controlled?
To derive precise results, it is important for other variables in an experiment to be controlled. Accuracy and precision are the key factors of every practical experiment carried out.
During the course of experiments, special emphasis is laid on the objective of the experiment. Procedures and precautions are highly objective-oriented. There are possibilities of errors as the surrounding becomes an integral part of the system in practicals.
Certain physical and chemical quantities are ignored in theoretical assessment, but they affect the practical work. Impurities and uncontrolled reactions can be barriers. Optimum conditions are sought before conducting experiments.