Answer:pull
Explanation:
If a system's internal energy increases by 250 kJ after the addition of375 kJ of energy as heat, what was the value ofthe work in the process?
(A) -625 kJ
(B) -125 kJ
(C) 125 kJ
(D) 625 kJ
Answer:
(B) -125 kJ
Explanation:
Going by the First Law of Thermodynamics it states that"
"A system can do work and increase it's internal energy provided we supply heat."
ΔU= q+w-----------1
where U= the internal heat
q= the quantity of heat added or removed from the system
w= the work done
Given
ΔU= 250kJ
q= 375kJ
from equation 1 make w subject of the formula we have
w= ΔU-q
w= 250-350
w= -125kJ
Which is one advantage of using a reflecting telescope instead of a refracting telescope?
Reflecting telescopes are less expensive.
Reflecting telescopes produce clearer images.
Reflecting telescopes require only concave lenses.
Reflecting telescopes usually take up less space.
Answer:
Reflecting telescopes take up less space, is the suitable answer.
Answer:
B, or 2: Reflecting telescopes produce clearer images.
Explanation:
Took the test
Flicks tongue stuck to the floor Porter he was triple dog dare to do it if the teacher Miss shields calls for help in the firetruck 0 mph to 42 mph in six seconds what is a fire trucks acceleration?
HELP DUE MONDAY!!!
Answer:
3.128 m/s^2
Explanation:
Acceleration is the change in velocity over the change in time. Final velocity is 42 mph and initial velocity is 0 mph, but we need to convert these values to meters per second (m/s).
To do that, we divide 42 by 2.237 and the result is 18.77.
Now we can calculate the change in velocity: 18.77 - 0 = 18.77 m/s.
Now we need the change in time: 6 s is the elapsed time, 0 s in the starting time. So 6 s - 0 s = 6 s.
Now we divide 18.77 by 6 s and obtain the answer, which is:
18.77 m/s ÷ 6 s = 3.128 m/s^2
describes the temperature at which a
solid's attractive forces are overcome and it
becomes a liquid.
Answer:
Melting point
Explanation:
it's constant temperature at which the bonds of a solid Crystal lattice are broken down by overcoming the attractive forces converting it to liquid
What's the enthalpy of neutralization and explain briefly how it relates to esterification
Answer:
The enthalpy of neutralization and its relation to esterification is explained below in details.
Explanation:
The conventional enthalpy variation of neutralization is the enthalpy exchange when extracts of an acid and an alkali respond together under conventional circumstances to generate 1 mole of water. Remark that the enthalpy change of neutralization is always estimated per mole of water produced.
What element needs just a single extra electron to have the same electron configuration as helium?
Answer:
Hydrogen
Explanation:
Helium has an atomic number Z = 2, that is, it has 2 protons. Since it is electrically neutral it also has 2 electrons. Thus, the electron configuration of helium is 1s².
Hydrogen has an atomic number Z = 1, that is, it has 1 proton. Since it is electrically neutral it also has 1 electron. Thus, the electron configuration of hydrogen is 1s¹.
If hydrogen gains a single extra electron to form H¹⁻, it acquires the same electron configuration than helium.
True or False: Most metals are found to occur naturally in their uncombined states.
Answer:
I think it's true. But I'm not sure
Answer:
True
Explanation:
How many moles of O2 are needed to react
with 24 moles of C2H6?
2C2H6 + 702 — 4CO2 + 6H20
Explanation:
Mole ratio of Ethane to Oxygen = 2 : 7
Moles of O2 needed = 24 moles * (7/2) = 84 moles.
Moles are the ratio of the mass and the molar mass of the substance. 84 moles of oxygen are needed to react with Ethane.
What are moles?Moles are the unit of the measurement of small entities like molecules, atoms, or particles.
The reaction is shown as:
[tex]\rm 2C_{2}H_{6} +7O_{2} \rightarrow 4CO_{2} + 6H_{2}O[/tex]
From the reaction, it can be said that the mole ratio of ethane [tex](\rm C_{2}H_{6})[/tex] and oxygen [tex](\rm O_{2})[/tex] is 2:7.
Then moles of oxygen will be,
[tex]24 \times \dfrac{7}{2} = 84[/tex]
Therefore, 84 moles of oxygen are needed to react with 24 moles of ethane.
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. Bob plants some seeds in a small cup. He puts the cup in the light and waters the soil every day. After 4 days, the seedlings emerge from the soil. What can Bob conclude?
answers in the picture I HAVE TO TURN IN THIS AT 10:30 PLEASE HELP ME OUT
The seedlings exerted an upward pushing force on the soil explains why the
seeds emerged from the soil.
Bob watered the soil in which the seed absorbs the water through the coat ,
the seed coat and embryo begins to enlarge and emerge from the soil.
The hydrated enzymes become active thereby increasing metabolic
activities and energy production which is needed for the growth of the plant.
The energy helps the seed exert an upward force on the soil.
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What is the molar mass of sodium bicarbonate, NaHCO3.
Answer:
84.01 g/mol
Explanation:
Look at your periodic table for the atomic mass for Na, H, and C, and O
Na = 22.99
H = 1.01
C = 12.01
O = 16.00
They are three oxygen atoms. So 16(3) = 48
Now do basic math.
22.99 + 1.01 + 12.01 + 16.00(3) = 84.01 g/mol.
Literally found this in a YouTuube video lol. Hope it helped doe!
The molar mass of sodium bicarbonate (NaHCO₃) is approximately 84.01 grams per mole (g/mol).
To calculate the molar mass of sodium bicarbonate (NaHCO₃), you need to sum the atomic masses of all the atoms in the chemical formula.
The atomic masses:
Sodium (Na) = 22.99 g/mol
Hydrogen (H) = 1.01 g/mol
Carbon (C) = 12.01 g/mol
Oxygen (O) = 16.00 g/mol
Now, let's calculate the molar mass of NaHCO₃:
Molar mass of NaHCO₃ = (1 * Na) + (1 * H) + (1 * C) + (3 * O)
Molar mass of NaHCO₃ = (1 * 22.99 g/mol) + (1 * 1.01 g/mol) + (1 * 12.01 g/mol) + (3 * 16.00 g/mol)
Molar mass of NaHCO₃ = 22.99 g/mol + 1.01 g/mol + 12.01 g/mol + 48.00 g/mol
Molar mass of NaHCO₃ = 84.01 g/mol
Therefore, the molar mass of sodium bicarbonate (NaHCO₃) is approximately 84.01 grams per mole (g/mol).
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g In this equation stands for the Rydberg energy, and stands for the principal quantum number of the orbital that holds the electron. (You can find the value of the Rydberg energy using the Data button on the ALEKS toolbar.) Calculate the wavelength of the line in the emission line spectrum of hydrogen caused by the transition of the electron from an orbital with to an orbital with . Round your answer to significant digits.
The complete question is attached to this answer
Answer:
2.75 * 10^-5 m
Explanation:
The energy of the absorbed photon = ΔE
ΔE = - Ry (1/n^2 final - 1/n^2initial)
Given that Ry = 2.18 *10^-18 J
nfinal = 9
ninitial =8
ΔE = - 2.18 *10^-18 (1/9^2- 1/8^2)
ΔE = - 2.18 *10^-18 (0.0123 - 0.0156)
ΔE = 7.194 * 10^-21 J
But
ΔE =hc/λ
h = 6.6 *10^-34Js
c= 3 * 10^8 ms-1
λ= the unknown
λ= hc/ΔE
λ= 6.6 *10^-34 * 3 * 10^8/ 7.194 * 10^-21
λ= 2.75 * 10^-5 m
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Which force keeps the planets from floating off into space?
Earth’s gravity
the Sun’s gravity
the moon’s gravity
Milky Way’s gravity
Answer:
Suns gravity
Explanation:
Answer: 2021
B
The Sun's gravity
Explanation: Just took the big test
Question 1 / 1
Which of the following is a covalent bond?
A. CO2
B. NaCl
C. Fe2O,
Answer:
Chemistry deals with matter, and there is a tremendous variety of matter in the universe. The behavior of matter depends on the type of elements that are present and on the structure of those elements—how they are connected to make a molecule. In this exercise, you will evaluate some representative models to develop the rules used to classify a compound, to predict the formula of a compound, and to name the compound. This exercise is just the beginning of the work needed to be done to master the rules of writing formulas and nomenclature. Your textbook has tables of the names and formulas of common cations and anions, and discusses the rules of nomenclature in detail. You will need to spend some time with this material, as the formal rules of nomenclature may not be presented in lecture, although they will certainly be used in discussions of Lewis structures and reaction chemistry.
Explanation:
In a covalent compound, valence electrons are shared between the two atoms in the bond. These can be evenly shared (covalent bond) or unevenly shared (polar covalent bond). In an ionic bond, electrons are localized to one of the atoms (giving it an overall negative charge), while the other atom has an overall positive charge. The difference in electronegativity between the two atoms in the bond can help predict whether the bond is likely to be ionic, covalent, or polar covalent, as can the type of atoms involved (metals or non-metals). A bond with two identical atoms is always pure covalent, while a covalent bond with two different atoms is likely to be polar covalent.
What statement is not true about the field of science
Answer:
where are the statements?
Explanation:
HELP 20 POINTS
What is the frequency of an Electromagnetic wave has with wavelength 2.94 x 10^-8 cm?
Based on the principle of complementary colors, which colors or wavelengths of light would you expect to be most strongly absorbed by Cu2 ions?
Answer:
Red and Orange
Explanation:
Complementary colors are those colours located across from each other on a color wheel. If we look at the colour wheel attached to this answer, we will see various complementary colours shown.
A good look at the attached colour wheel reveals that blue Cu2+ ions absorbs light around the red and orange portions of the visible spectrum.
A precipitate of lead chloride is formed when silver chloride is dissolved in a saturated solution of lead chloride due to g
Answer:
Due to "Common ion effect".
Explanation:
Lead chloride and Silver chloride have an ion in common which is Cl-, when these two solutions are dissolved, more chloride reacts with lead which shifts equilibrium position to the right hence precipitating out.
Which type of energy is the tree changing the light energy into?
Answer: Chemical energy
Explanation: In this case plants convert light energy (1) into chemical energy, (in molecular bonds), through a process known as photosynthesis. Most of this energy is stored in compounds called carbohydrates. The plants convert a tiny amount of the light they receive into food energy.
Answer:
chemical energy
In this case plants convert light energy into chemical energy, (in molecular bonds), through a process known as photosynthesis. Most of this energy is stored in compounds called carbohydrates. The plants convert a tiny amount of the light they receive into food energy.
Explanation:
The pressure of a sample of argon gas was increased from 3.89 atm to 8.73 atm at constant temperature. If the final volume of the argon sample was 18.4 L, what was the initial volume of the argon sample? Assume ideal behavior.
Answer:
41.29 LExplanation:
The initial volume can be found by using the formula for Boyle's law which is
[tex]P_1V_1 = P_2V_2[/tex]
Since we are finding the initial volume
[tex]V_1 = \frac{P_2V_2}{P_1} \\[/tex]
From the question we have
[tex]V_1 = \frac{8.73 \times 18.4}{3.89} = \frac{160.632}{3.89} \\ = 41.293573...[/tex]
We have the final answer as
41.29 LHope this helps you
28. After 3 substances are mixed, an odor emits
a. chemical change
b. physical change
c. thermal energy is used
a do
Answer:
a. chemical change
Explanation:
A chemical change can cause an odor, however a physical change cannot, and the use of thermal energy will only make an object colder, not give it an odor.
0.450 moles of oxygen gas is subjected to a pressure of 3.00 atm and 75 oC.
What is it's volume (in Liters)?
Use this formula PV=nRT
Rearrange formula , question want V ,so
V=nRT/P
given
P= 3.00 atm
n=0.450 moles
R is ideal gas constant = 0.08206 L atm mol-¹K-¹
T in Kelvin so , (75 + 273)= 348 Kelvin (K)
Then insert all this information given with that rearranged formula V=nRT/P
so, V= (0.45)(0.08206)(348) / 3.00 = 4.284 LA saturated hydrocarbon having molecular formula CnH2n+2 diffuses through a porous membrane twice as fast as sulphur dioxide. Calculate the volume occupied by the hydrocarbon at27°C and 2atm ?
Help me fast !
Answer:
12.3 L
Explanation:
Now we have that the rate of diffusion of the saturated hydrocarbon is R1
Rate of diffusion of sulphur dioxide is R2
Molar mass of hydrocarbon is M1
Molar mass of sulphur dioxide is 64 gmol-1
From Graham's law;
R1/R2 = √64/M1
2/1 =√64/M1
(2/1)^2 = (√64/M1)^2
4/1 = 64/M1
4M1 =64
M1 = 16
To obtain the number of moles of the gas;
(n*12) + (2n + 2) 1 = 16
12n + 2n + 2 = 16
14n + 2 = 16
14n = 16 - 2
n = 14/14
n = 1
Hence the hydrocarbon is CH4
Volume occupied by CH4 at STP = 22.4 L
Hence;
P1 = 1 atm
T1 = 273 K
V1 = 22.4 L
T2 = 300 K
P2 = 2 atm
V2 = ?
P1V1/T1 = P2V2/T2
P1V1T2 = P2V2T1
V2 = P1V1T2/P2T1
V2 = 1 * 22.4 * 300/2 * 273
V2 = 12.3 L
The volume occupied by the hydrocarbon at 27 °C and 2 atm is 12.31 L
Let the hydrocarbon be initially at standard temperature and pressure (STP)
Thus, we can obtain the new volume of the hydrocarbon by using the combined gas equation as illustrated below:
Initial volume (V₁) = STP = 22.4 L Initial pressure (P₁) = STP = 1 atmInitial temperature (T₁) = STP = 273 KFinal temperature (T₂) = 27 °C = 27 + 273 = 300 KFinal pressure (P₂) = 2 atmFinal volume (V₂) =?P₁V₁ / T₁ = P₂V₂ / T₂
(1 × 22.4) / 273 = (2 × V₂) / 300
22.4 / 273 = (2 × V₂) / 300
Cross multiply
273 × 2 × V₂ = 22.4 × 300
546 × V₂ = 6720
Divide both side by 546
V₂ = 6720 / 546
V₂ = 12.31 L
Thus, the volume occupied by the hydrocarbon at 27 °C and 2 atm is 12.31 L
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A radical is a reactive intermediate with a single ____________ electron, formed by ____________ of a covalent bond. Allylic radicals are stabilized by ____________ , making them ____________ stable than tertiary radicals. A compound that contains an especially weak bond that serves as a source of radicals is called a radical ____________ . Treatment of cyclohexene with N-bromosuccinimide in the presence of light leads to ____________ by ____________ intermediates.
1. A radical is a reactive intermediate with a single ____________ electron, formed by ____________ of a covalent bond.
1. A: Unpaired, and homolysis
2. Allylic radicals are stabilized by ____________ , making them ____________ stable than tertiary radicals.
2. A: Resonance, and more
3. A compound that contains an especially weak bond that serves as a source of radicals is called a radical ____________ .
3. A: Initiator
4. Treatment of cyclohexene with N-bromosuccinimide in the presence of light leads to ____________ by ____________ intermediates.
4. A: Allylic substitution by radical
Complete the statement of equality.
Answer:
This is not a viable question.
Explanation:
A certain reaction requires 0.250 moles of Na2SO4. How
much sodium sulfate should the chemist weigh out to perform
the reaction?
The chemist weigh out 35.51 g Na2SO4
Further explanationGiven
0.250 moles of Na2SO4
Required
weight of Na2SO4
Solution
A mole is a number of particles(atoms, molecules, ions) in a substance
This refers to the atomic total of the 12 gr C-12 which is equal to 6.02.10²³, so 1 mole = 6.02.10²³ particles
Moles of a substance can also be determined from its molecular weight
[tex]\tt mol=\dfrac{mass}{MW}[/tex]
For 0.250 moles of Na2SO4, mass =
[tex]\tt mass=mol\times MW\\\\mass=0.25\times 142,04 g/mol\\\\mass=35.51~g[/tex]
Cups ans glasses are taking too long to air dry. This could be caused by
Answer: Servsafe 9
Explanation:
Remove food from the surface
clean the surface
rinse the surface
sanitize the surface
allow the surface to air dry
Cups and glasses are taking too long to air dry. This could be caused by the ventilation system not working properly. The correct option is D.
What is ventilation?A ventilation system is a mechanical device that is normally created and built to supply airflow into and out of a structure or other enclosed space. Because air is provided by a functioning ventilation system, moisture on surfaces like cups and glasses can dry more quickly.
It is possible to describe air-drying as a technique or process for removing moisture from surfaces using either heated, forceful, or dry air. Therefore, air drying aids in making the surface of goods like cups and glasses dry, or free of moisture.
Thus, the correct option is D. The ventilation system not working properly.
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The question is incomplete. Your most probably complete question is given below:
A. Incorrect timing of the wash cycle.
B. An improper use of chemical sanitizer.
C. The water temperature being too high.
D. The ventilation system not working properly.
How many grams are in 2.3 x 1024 formula units of KNO3?
390 g KNO₃
General Formulas and Concepts:ChemistryAtomic Structure
Reading a Periodic TableUsing Dimensional AnalysisAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.MathPre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to Right Explanation:Step 1: Define
2.3 × 10²⁴ formula units KNO₃
Step 2: Identify Conversions
Avogadro's Number
Molar Mass of K - 39.10 g/mol
Molar Mass of N - 14.01 g/mol
Molar Mass of O - 16.00 g.mol
Molar Mass of KNO₃ - 39.10 + 14.01 + 3(16.00) = 101.11 g/mol
Step 3: Convert
[tex]2.3 \cdot 10^{24} \ formula \ units \ KNO_3(\frac{1 \ mol \ KNO_3}{6.022 \cdot 10^{23} \ formula \ units \ KNO_3} )(\frac{101.11 \ g \ KNO_3}{1 \ mol \ KNO_3} )[/tex] = 386.172 g KNO₃
Step 4: Check
We are given 2 sig figs. Follow sig fig rules and round.
386.172 g KNO₃ ≈ 390 g KNO₃
PLEASE HELP WILL GIVE BRAINLIEST
Answer:
Coefficients represents no of moles while subscripts represent no of atoms.
Answer:
Coefficients came before formula . Example = 4CO means there are 4 molecules of carbonmonooxide.
Subscripts came after and below the formula . Example = Oxygen gas in which 2 is a subscript which means there are 2 atoms of Oxygen in 1 molecule of Oxygen i.e. oxygen gas
you weigh out 43.9 g of potassium (K). How many moles of potassium did you weigh? How many atoms?
Answer:
1.12 moles of potassium
6.76x10²³ atoms of potassium
Explanation:
In order to convert g of potassium to moles, we need to use its molar mass (which we can find via the periodic table):
Molar Mass of K = 39.09 g/mol43.9 g K ÷ 39.09 g/mol = 1.12 mol KThen, to convert moles into atoms, we use Avogadro's number (6.023x10²³ atoms per mole):
1.12 mol K * 6.023x10²³[tex]\frac{atoms}{mol}[/tex] = 6.76x10²³ K atoms