Answer:
B
Explanation:
For a theoretical yield of 23 g and actual
yield of 13 g, calculate the percent yield for a
chemical reaction.
1. 63.6364
2. 76.4706
3. 71.4286
4. 57.1429
5. 56.5217
6. 40
7. 70
8. 60
9. 52.6316
10. 41.6667
Answer in units of %.
Answer:
5. 56.5217
Explanation:
Calculate percent yield by (actual yield / theoretical yield) times 100
(13/23) x 100 = 56.52173913
how do you think a device could change the sound that we hear? Make sure you use vocabulary such as frequency, energy and amplitude
Answer:
good luck tho
Explanation:
DUE IN 1 MINUTE HELP I'M DESPERATE
What will be the pH of a buffer solution containing an acid of pKa7.5, with an acid concentration exactly one fourth of that of the conjugate base
Answer: pH of buffer solution is 8.1
Explanation:
The formula for the Henderson–Hasselbalch equation is:
[tex]pH=pK_a+\log\frac{[A^-]}{[HA]}[/tex]
[tex]pH[/tex] is the concentration of [tex][H^+][/tex]
[tex]pK_a[/tex] is the acid dissociation constant,
[tex]A^-[/tex] and [tex]HA[/tex] are concentrations of the conjugate base and starting acid.
Putting in the values we get:
[tex]pH=7.5+\log\frac{x}{\frac{x}{4}}[/tex]
[tex]pH=8.1[/tex]
Thus pH of buffer solution is 8.1
T/F___ At the eutectic composition, an alloy can solidify at a constant temperature.___ For effective dispersion strengthening, the dispersed phase should be needle-like, as opposed to round___ Intermetallic compounds are usually hard and brittle.___ For effective dispersion strengthening, the dispersed phase should be continuous.___ Stoichiometric intermetallic compounds exist overa range of compositions.___ Faster solidification results in smaller interlamellar spacing
Answer:
TRUEFALSETRUEFALSEFALSETRUEExplanation:
At the eutectic composition, an alloy can solidify at a constant temperature : TRUE . this is because at eutectic composition the type of reaction that takes place there is invariant reaction in its thermal equilibrium For effective dispersion strengthening, the dispersed phase should be needle-like, as opposed to round : FALSE. because the rounded shape will not cause a crack. Intermetallic compounds are usually hard and brittle : TRUE. because Intermetallic compounds prevents dislocation movements and this makes them brittle and hardFor the effective dispersion and strengthening, the dispersed phase should be continuous : FALSE. this is because the dispersed precipitate must be small and not continuous Stoichiometric intermetallic compounds exist over a range of compositions : FALSEFaster solidification results in smaller interlamellar spacing : TRUEA moving 10 kilogram object has 20 Joules of kinetic energy. What is its velocity?
4 m/s
2 m/s
10 m/s
200 m/s
Which statement is accurate about variations?
Organisms with variations that give an advantage are more likely to survive
Organisms with variations are less likely to pass these variations to their offspring
In all cases vanations become more common in a population
In all cases variations affect how likely it is that an organism reproduces
Answer:
A,C,D
Explanation:
Variations effect the likelyhood of survival for a organism, it can give off an advantage or disadvantage.
Brainliest? pls
You have to decide to change the temperature at which you run a certain reaction in hope of obtaining more product more quickly. You find that you actually get less of the desired product, although you get to the equilibrium state more quickly. Explain what happened.
Answer:
see explanation
Explanation:
The reaction has a negative rate law; i.e., Rate = - ΔConcentration / ΔTime which is graphically a negative slope for the plot of Rate as a function of reactant concentration. => Rate ∝ f(Reactant Concentration). However, by raising the temperature, an increase the probability of reaction occurs and the formation of more product.
A balloon at 30.0 C has a volume of 222 ml. if the temperature is increased to 62.1 C and the pressure remains constant, what will the new volume be, in mL?
The concept Charles's law is used here to determine the new volume. At the condition of constant pressure the new volume of the balloon is 459.54 mL.
What is Charles's law?At constant pressure, the volume of a given mass of gas is directly proportional to the temperature on Kelvin scale. Mathematically, the law can be expressed as follows:
V = constant × Temperature
V / T = Constant
V = Volume
T = Temperature
The Charles's law also explained that at -273°C, the volume of all the gases will become zero. This temperature is defined as the absolute zero.
For two different gases with volumes V₁ and V₂ and temperatures T₁ and T₂ is represented as:
V₁ / T₁ = V₂ / T₂
V₂ = V₁T₂ / T₁
222 × 62.1 / 30.0 = 459.54 mL
Thus the new volume of balloon is 459.54 mL.
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For many years chloroform (CHCl3) was used as an inhalation anesthetic in spite of the fact that it is also a toxic substance that may cause severe liver, kidney, and heart damage. Calculate the percent composition by mass of this compound to four significant figures.
Answer:
SEE EXPLANATION
Explanation:
We must first obtain the molar mass of CHCl3 as follows;
CHCl3 = ( 12.01 * 1 )+ (1.008 * 1 ) + ( 35.45 * 3 ) => 119.37 g/mol
Then we obtain the percentage by mass of each element
For Carbon = ( atomic mass C / molar mass CHCl3 ) * 100
C = (12.01 / 119.37 ) * 100
C = ( 0.1006 * 100 )
C = 10.06 %
For Hydrogen :
H = ( atomic mass H / molar mass CHCl3 ) * 100
H = ( 1.008 / 119.37 ) * 100
H = 0.008444 * 100
H = 0.8444 %
For Chlorine :
Cl ( molar mass Cl3 / molar mass CHCl3 ):
Cl = ( 3 * 35.5 / 119.37 ) * 100
Cl = ( 106.5 / 119.37 ) * 100
Cl = 0.8921 * 100
Cl = 89.92%
The elemental composition of propane gas (C3H8) is 81.68% C and 18.32% H by mass. What is the maximum amount of C3H8 in grams that can be formed from 160.0 g C and 160.0 g H
Molar mass of C3H8 = C 3 (12.01 g/mol) = 36.03 (g/mol)
H 8 (1.008 g/mol) = 8.064 (g/mol)
44.09 (g/mol)
74.6 g propane x 1 mole propane x 6.022 x 10
23
molecules
44.09 g propane 1 mole propane
= 1.02 x 10
24 molecules propane
About how many atoms of Mg are present in 24.3 grams of Mg?
5.85 x 1025
4.35 x 1019
c
4.81 X 1024
6.02 x 103
Answer:
D is the answer i think
Explanation:
Why do you think there are different stars in each nighttime section of the artifact?
Answer:
The sky looks different in each nighttime section of the artifact because the artifact sections represent different seasons. ... Different constellations are visible on different nights throughout the year because of the earth's orbit. The Earth orbits around the sun. A full orbit is 365 days or one year.
Explanation:
What is the volume of 0.200 moles of O2 gas at STP?
Answer:
4.48 L O2
Explanation:
At STP, a mole of any gas contains 22.4 liters. Therefore, we simply have to multiply the amount of moles by 22.4
0.2mol O2 ( 22.4 L) = 4.48 L O2
You prepare a standard by weighing 10.751 mg of compound X into a 100 mL volumetric flask and making to volume. You further dilute this solution 5 mL to 25 mL. This standard gives an area of 4,374. Your sample is prepared by adding 5 mL of sample solution into a 50 mL flask and making to volume. This gives an area count of 2,582. Calculate the concentration of compound X in the sample - prior to dilution.
Answer:
0.12693 mg/L
Explanation:
First we calculate the concentration of compound X in the standard prior to dilution:
10.751 mg / 100 mL = 0.10751 mg/mLThen we calculate the concentration of compound X in the standard after dilution:
0.10751 mg/mL * 5 mL / 25 mL = 0.021502 mg/LNow we calculate the concentration of compound X in the sample, using the known concentration of standard and the given areas:
2582 * 0.021502 mg/L ÷ 4374 = 0.012693 mg/LFinally we calculate the concentration of X in the sample prior to dilution:
0.012693 mg/L * 50 mL / 5 mL = 0.12693 mg/LDominant traits are more common in a population then recessive traits
false
true
Answer:
No Just because a trait is dominant does not mean that it is present in the population
Explanation:
A mixture of gas with a total pressure 1.47 atm is found to contain oxygen (O2), carbon monoxide (CO), and nitrogen (N2). What is the partial pressure of carbon monoxide (CO) if the partial pressure of O2is 0.82 atm and the partial pressure of N2is 0.36 atm?
Answer:
0.29 atm
Explanation: add both partial pressure and subtract from total pressure
9.16 liters of CO2 weighs how many grams?
Your answer
Answer:
18.0g of CO₂ are present in 9.16L
Explanation:
To solve this question we must use:
PV = nRT
In order to find the moles of the gas and with its molar mass (44.01g/mol for CO₂) we can find the mass of the gas
Assuming STP conditions:
P = 1atm at STP
V = 9.16L
n are the moles of CO₂
R = 0.082atmL/molK
T = 273.15K
Replacing:
PV / RT = n
1atm*9.16L / 0.082atmL/molK*273.15K = n
0.409 moles = Moles of CO₂
The mass is:
0.409 moles CO₂ * (44.01g / mol) =
18.0g of CO₂ are present in 9.16LHow many moles of magnesium nitrate are produced when he reacts 0.34 moles of nitric acid with excess magnesium?
The energy of flowing electrons
A. A. LightLightB. B. ChemicalChemicalC. C. ElectricalElectricalD. D. TransformationTransformationE. E. MechanicalMechanical
Answer:
C. ElectricalElectrical
Explanation:
( it might be wrong pls dont report me just let me kno y its wrong )
Why do scientists think that liquid water might have once existed on Mars?
Answer: The discovery of three buried lakes. Scientists think that a long time ago there were lakes and rivers, etc on Mars. Now of course, you can't see any visible water sources on the surface.
Answer:
Almost all water on Mars today exists as ice, though it also exists in small quantities as vapor in the atmosphere.[5] What was thought to be low-volume liquid brines in shallow Martian soil, also called recurrent slope lineae may be grains of flowing sand and dust slipping downhill to make dark streaks.The only place where water ice is visible at the surface is at the north polar ice cap. Abundant water ice is also present beneath the permanent carbon dioxide ice cap at the Martian south pole and in the shallow subsurface at more temperate conditions. More than 5 million km3 of ice have been detected at or near the surface of Mars, enough to cover the whole planet to a depth of 35 meters. Even more ice is likely to be locked away in the deep subsurface.
Some liquid water may occur transiently on the Martian surface today, but limited to traces of dissolved moisture from the atmosphere and thin films, which are challenging environments for known life. No large standing bodies of liquid water exist on the planet's surface, because the atmospheric pressure there averages just 600 pascals , a figure slightly below the vapor pressure of water at its melting point; under average Martian conditions, pure water on the Martian surface would freeze or, if heated to above the melting point, would sublime to vapor. Before about 3.8 billion years ago, Mars may have had a denser atmosphere and higher surface temperatures, allowing vast amounts of liquid water on the surface, possibly including a large ocean that may have covered one-third of the planet.Water has also apparently flowed across the surface for short periods at various intervals more recently in Mars' history. Aeolis Palus in Gale Crater, explored by the Curiosity rover, is the geological remains of an ancient freshwater lake that could have been a hospitable environment for microbial life.Many lines of evidence indicate that water ice is abundant on Mars and it has played a significant role in the planet's geologic history.The present-day inventory of water on Mars can be estimated from spacecraft images, remote sensing techniques (spectroscopic measurements, radar, etc.), and surface investigations from landers and rovers.Geologic evidence of past water includes enormous outflow channels carved by floods, ancient river valley networks, deltas and lakebeds,and the detection of rocks and minerals on the surface that could only have formed in liquid water. Numerous geomorphic features suggest the presence of ground ice (permafrost)and the movement of ice in glaciers, both in the recent past and present. Gullies and slope lineae along cliffs and crater walls suggest that flowing water continues to shape the surface of Mars, although to a far lesser degree than in the ancient past.Although the surface of Mars was periodically wet and could have been hospitable to microbial life billions of years ago, the current environment at the surface is dry and subfreezing, probably presenting an insurmountable obstacle for living organisms. In addition, Mars lacks a thick atmosphere, ozone layer, and magnetic field, allowing solar and cosmic radiation to strike the surface unimpeded. The damaging effects of ionizing radiation on cellular structure is another one of the prime limiting factors on the survival of life on the surface. Therefore, the best potential locations for discovering life on Mars may be in subsurface environments. Large amounts of underground ice have been found on Mars; the volume of water detected is equivalent to the volume of water in Lake Superior. In 2018, scientists reported the discovery of a subglacial lake on Mars, 1.5 km (0.93 mi) below the southern polar ice cap, with a horizontal extent of about 20 km (12 mi), the first known stable body of liquid water on the planet.Understanding the extent and situation of water on Mars is vital to assess the planet’s potential for harboring life and for providing usable resources for future human exploration. For this reason, "Follow the Water" was the science theme of NASA's Mars Exploration Program (MEP) in the first decade of the 21st century. NASA and ESA missions including 2001 Mars Odyssey, Mars Express, Mars Exploration Rovers (MERs), Mars Reconnaissance Orbiter (MRO), and Mars Phoenix lander have provided information about water's abundance and distribution on Mars.Mars Odyssey, Mars Express, MRO, and Mars Science Lander Curiosity rover are still operating, and discoveries continue to be made.
The trait that shows up in the first generation.
Recessive
Dominant
Ok
Answer:
Dominant
Explanation:
hope this help
A car generates 2552 N and weighs 2250 kg. What is its rate of acceleration
2 m/s ^2
0.88m/s^2
5,742,000m/s^2
1.13m/s^2
Answer:
[tex]a=1.134\frac{m}{s^2}[/tex]
Explanation:
Hello there!
In this case, by considering the physical definition of force in terms of mass and acceleration:
[tex]F=m*a[/tex]
Given the generated force and the involved mass, we can compute the required acceleration as shown below:
[tex]a=\frac{F}{m}\\\\a=\frac{2552N}{114kg}[/tex]
Yet it is necessary to break out Newtons to:
[tex]a=\frac{2552\frac{kg*m}{s^2} }{114kg}\\\\a=1.134\frac{m}{s^2}[/tex]
Best regards!
Two elevators carry five passengers to the fifth floor. However, the elevators do not do the same work. Choose the best factor for
determining the amount of work the elevators did.
A.the speed of the elevator
B.the weight of the passengers
C.the number of buttons pressed
Will mark brainlist pls help!
Answer:
B the weight of the passengers
Can light bend around corners to reach an object
Answer: Yes, light can bend around corners. In fact, light always bends around corners to some extent.
Explanation:This is a basic property of light and all other waves. ... The ability of light to bend around corners is also known as "diffraction".
I a doing an exam in science pls help.
What type of energy comes from the motion of tiny particles of matter?
Answer:
heat
Explanation:
Answer:
Thermal Energy
Explanation:
Lab: Enthalpy.
What were the learning goals of this lab experiment? Check all that apply.
to use mass and temperature data to do computations involving heat
to demonstrate that different reactions have different enthalpies
to compute a reaction’s enthalpy directly using mass measurements and a calorimeter
to compute the enthalpy of a reaction that cannot be measured directly using a simple calorimeter
Hess
’s law allows you to find the net enthalpy of the magnesium combustion by adding the enthalpies of intermediate reactions.
To find the enthalpy of a reaction in the lab, you measured the
mass
of the reactants
and the
temperature
change during the reaction.
In both Reactions 1 and 2, the temperature change was
positive
, meaning that the
reactions
gave off
heat.
Answer:
to use mass and temperature data to do computations involving heat
to compute a reaction’s enthalpy directly using mass measurements and a calorimeter
To find the enthalpy of a reaction in the lab, you measured the mass
of the reactants
and the
temperature
change during the reaction.
Explanation:
Was that good?
Enthalpy is a thermodynamic system's internal energy total as well as the volume times pressure ratio.
What is Enthalpy?Enthalpy is a property or state function that resembles energy; it has the same dimensions as energy and is therefore measured in joules or ergs. The value of enthalpy is solely dependent on the temperature, pressure, and composition of the system, not on its history.
Enthalpy, denoted by the symbol H, is the sum of the internal energy, denoted by E, and the product of the pressure and volume, denoted by PV.
The change in internal energy is equal to the heat transmitted to, less the work done by, the system, according to the law of energy conservation.
Therefore, Enthalpy is a thermodynamic system's internal energy total as well as the volume times pressure ratio.
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4. What is the molarity of a solution that contains 65g of sodium nitrate in 750? ml of solution?
Answer:
1.02 M
Explanation:
Solution contains 65g of sodium nitrate
Volume of solution = 750 ml
Now, Molar mass of sodium nitrate from online values = 84.9947 g/mol
Thus, it means 84.9947 g/mol of sodium nitrate dissolved in 1000 mL of water will be equal to 1 M molarity.
Thus;
Molarity of solution = (65/750) × (1000) × (1/84.9947) = 1.02 M
HELPP PLZ FAST WILL GIVE BRAINLIEST
Benzene, a nonpolar, colorless solute, is most commonly found in oil and is a major component in gasoline.
In which of these two solvents will benzene most likely dissolve?
Solvent
Characteristics
A
Carbon tetrachloride
• Colorless liquid, noncombustible
• Nonpolar
Ethanol
• Flammable, colorless liquid
• Polar
Methanol
• Distinctive odor; volatile, colorless liquid
• Polar
Cyclohexane
• Strong odor; flammable; colorless liquid
• Nonpolar
OA
OB
ОС
OD
Where are electrons found in an atom?
Answer:
outside the nucleus
Explanation: