Answer: Cathode rays are made up of negatively charged particles.
Atoms contain negatively charged particles.
A average marathon runner run the 26.1 miles in 4 hrs 30 minutes. What is the runners average pace in miles/minutes.
Explanation:
4hr 30 m = 270 min
270/ 26.1 = 10. 34
1 mile per 10.34 mins
Which of the following changes lead to a decrease in entropy?
a. mixing of pure gases
b. sugar dissolving in coffee
c. melting snow
d. the sublimation (vaporization) of dry ice (solid carbon dioxide)
e. halving the volume of a gas
Answer:
halving the volume of a gas
Explanation:
Entropy refers to the degree of disorderliness of a system. The greater the volume of a gas, the greater its entropy. The entropy of a system is directly proportional to its volume.
Hence a decrease in the volume of a gas leads to a decrease in its entropy. Ultimately, if the volume of a given mass of gas is halved, its entropy decreases according.
What is the mass, in grams, of 1.33 mol of water, H2O?
Answer:
24.0g H2O
Explanation:
1.33 mol (18.016g/1 mol) = 24.0g H2O
Which of the following statements is true about the arrangement of particles in matter?
B. The particles in aliquid are spread farther apart than the particles in a gas.
A. The particles in a gas are closer together than the particles in a liquid
D. The particles in a solid are spread farther apart than the particles in a liquid
C. The particles in a gas are spread farther apart than the partides in a solid
Answer:
C. The particles in a gas are spread farther apart than the particles in a solid
Explanation:
Solids are made up of tightly-packed particles that form a rigid shape. Liquids are comprised of loosely connected particles that can slightly move. Gases are made up of fast-moving disconnected particles that are spread far apart.
which of the following best describes a non metal
Answer:
-a nonmetal is a substance that lacks the characteristics of a metal.
-Seventeen elements are generally classified as nonmetals: most are gases (hydrogen, helium, nitrogen, oxygen, fluorine, neon, chlorine, argon, krypton, xenon and radon); one is a liquid (bromine); and a few are solids (carbon, phosphorus, sulfur, selenium, and iodine).
3.0 moles of nitrogen is reacted with 11.0 moles of hydrogen to produce ammonia according to the chemical equation shown below. Which one of the following statements is false?
N2(g) + 3 H2(g) → 2 NH3(g)
a. Hydrogen is the excess reactant.
b. 2.0 moles of hydrogen are left over.
c. 12.0 moles of ammonia are produced.
d. Nitrogen is the limiting reactant.
Answer:
c
Explanation:
From the equation, we can say that we need thrice the number of hydrogen than that of nitrogen
we are given 3 moles of nitrogen and 11 moles of hydrogen
but thrice the number of moles of nitrogen is 9, hence we have hydrogen in excess or Hydrogen is the excess reagent
Since we had 11 moles of Hydrogen and we only needed 9, 2 moles of hydrogen are left over
From the equation, we can see that the moles of ammonia formed will be twice the moles of nitrogen
Since 3 moles of nitrogen are used, the reaction will give us 6 moles of Ammonia and NOT 12 moles, therefore c is the correct answer
Since we have hydrogen in excess, our reaction is being limited because we have less Nitrogen, Hence Nitrogen is the Limiting Reagent
Option C is the only false statement
The false statement is that "12.0 moles of ammonia are produced"
According to the equation of reaction:
N₂ + 3H₂ >>>>> 2NH₃
1 mole of N₂ reacts with 3 moles of H₂
3 moles of N₂ will react with 9 moles of H₂
Since 3 moles of N₂ is said to react with 11 moles of H₂ (instead of 9 moles of H₂), H₂ is in excess by 2 moles. That is, N₂ is the limiting reactant.
Since N₂ is the limiting reactant:
1 mole of N₂ produces 2 moles of NH₃
3 moles of N₂ will produce 6 moles of NH₃
Therefore, we can conclude that:
Hydrogen is the excess reactant2.0 moles of hydrogen are left overNitrogen is the limiting reactantLearn more here: https://brainly.com/question/19555927
what is the state of the substance at room temperature (20°c)
Answer:
dez nuts. the forth quauter in ur girls buttr
Gas is well separated with no regular arrangement, liquids are close together and solids are tightly packed. Solid, liquid, and Gas are the state of substances at room temperature.
What is the state of substance?There are three state of substances:
solidLiquidGasThe chair you are sitting on is a solid, the water you drink is liquid, and the air you breathe is a gas. The atoms and molecules don't change, but the way they move about does. Water, for example, is always made up of two hydrogen atoms and one oxygen atom.
Physical properties of a particular substance determine its state at room temperature. If both its normal melting point and its normal boiling point are below room temperature (20°C), the substance is a gas under normal conditions.
Oxygen is a gas at room temperature. If the normal melting point of a substance is below room temperature, the substance is a liquid at room temperature.
If both the normal melting point and the normal boiling point are above room temperature, the substance is a solid.
Therefore, solid, liquid and gas all exist as substances at room temperature.
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What is the use of density in the calculation of percentage by mass?
Answer:
First, the direct method requires recording the total mass of solution, and then evaporating off the solvent. The solid left behind is the solute, which is then weighed and used to calculate mass percent. Density can also be used to determine the mass percent of an unknown concentration.
in my opinion:)
How many sig figs are in 340.0 mL
Answer:
4
Explanation:
there is a decimal place present. so you would take away any zeros before the number.
Answer:
4 i think
Explanation:
What is the charge of a chromium ion that has lost 4 electrons?
Answer:
+2.
Explanation:
Hello,
In this case, since chromium has six valence electrons in its outer shell, when it loses four electrons it remains with two of them, therefore it charge as chromium ion is +2, so it is written as Cr⁺² and named as chormium (II) or hypochromous ion.
Best regards.
Draw the conjugate base for the acid (CH3)2C=OH+ Remember to include charges and non-bonding electrons where
necessary
Answer:
Explanation:
An acid is a substance that, when dissolved in water produces hydrogen ions, H⁺ as the only positive ion. e.g.
HCl ↔ H⁺ + Cl⁻
HNO₃ ↔ H⁺ + NO⁻₃
This process is known as ionization. The characteristics properties of an acid in solution are due to the presence of these hydrogen ions. In these reactions, the negative ions formed or sometimes the neutral compounds are usually known as the conjugate base of such acid.
From the given information, the conjugate base of the acid given can be seen in the attached image below.
The conjugate base for the acid is attached below.
What is an Acid?An acid is a substance that, when dissolved in water produces hydrogen ions, H⁺ as the only positive ion. e.g.
HCl ↔ H⁺ + Cl⁻
HNO₃ ↔ H⁺ + NO⁻₃
This process is known as ionization. The characteristics properties of an acid in solution are due to the presence of these hydrogen ions. In these reactions, the negative ions formed or sometimes the neutral compounds are usually known as the conjugate base of such acid.
The conjugate base of the acid given can be seen in the attached image below.
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An atomic model shows 19 protons, 20 neutrons, and 19 electrons. What is the mass number of the atom?
Bismuth oxide reacts with carbon to form bismuth metal: Bi2O3(s) + 3C(s) → 2Bi(s) + 3CO(g) When 775 g of Bi2O3 reacts with excess carbon, (a) how many moles of Bi form? mol Bi (b) how many grams of CO form? g CO
Answer:
(a) 3.33 mol Bi
(b) 140. g CO
Explanation:
Step 1: Convert 775g to moles
Bi Molar Mass - 208.98 g/mol × 2 = 417.98 g/mol
O Molar Mass - 16.00 g/mol × 3 = 48.00 g/mol
775g Bi₂O₃ ÷ 465.98 g/mol = 1.66316 mol Bi₂O₃
Step 2: Find the conversion from Bi₂O₃ to Bi
1 mole of Bi₂O₃ equals 2 moles of Bi
Step 3: Use Dimensional Analysis
1.66316 mol · [tex]\frac{2 \hspace{2} mol \hspace{2} Bi}{1 \hspace{2} mol \hspace{2} Bi_2O_3}[/tex] = 3.32632 mol Bi
3.32632 mol Bi ≈ 3.33 mol Bi (3 significant figures)
Step 4: Find the conversion from Bi₂O₃ to CO
1 mole of Bi₂O₃ equals 3 moles of CO
Step 5: Use Dimensional Analysis
1.66316 mol · [tex]\frac{3 \hspace{2} mol \hspace{2} CO}{1 \hspace{2} mol \hspace{2} Bi_2O_3}[/tex] = 4.98948 mol CO
Step 6: Find molar mass of CO and convert moles to grams
C - 12.01 g/mol
O - 16.00 g/mol
4.98948 mol CO · 28.01 g/mol = 139.775 g CO
139.775 g CO ≈ 140. g CO (3 significant figures)
Explain why some people use the term decimal system as a synonym for the metric system?
Answer:
The term Decimal is coined from the word Decimus. Decimus is a Latin word which means ‘tenth’.
The Decimal system is a system of numbering that is based on multiples of tens. It is flexible and easy to convert from one metric to another.
The preference of the term over the Metric System is because the word Metric is related more to the measurement of lengths if we looked at the origin of the word which is French.
Cheers!
To what volume (in mL) would you need to dilute 25.0mL of a 1.45 m solution of Kcl to make a 0.0245m solution of KCl
Answer:
The answer is
1479.60 mLExplanation:
In order to calculate the volume needed we use the formula
[tex]V_2 = \frac{C_1V_1}{C_2} [/tex]
where
C1 is the concentration of the stock solution
V1 is the volume of the stock solution
C2 is the concentration of the diluted solution
V2 is the volume of thevdiluted solution
From the question
C1 = 1.45 M
V1 = 25 mL
C2 = 0.0245 M
So we have
[tex]V_2 = \frac{1.45 \times 25}{0.0245} = \frac{36.25}{0.0245} \\ = 1479.59...[/tex]
We have the final answer as
1479.60 mLHope this helps you
The particles in a gas have more space between them because
Answer:
They are more spread out.
Explanation:
The atoms and molecules in gases are much more spread out than in solids or liquids. They vibrate and move freely at high speeds. A gas will fill any container, but if the container is not sealed, the gas will escape. Gas can be compressed much more easily than a liquid or solid.
Answer:
Explanation:
Explanation:
Gas – In a gas, particles are in continual straight-line motion. The kinetic energy of the molecule is greater than the attractive force between them, thus they are much farther apart and move freely of each other. In most cases, there are essentially no attractive forces between particles
You heat 51 grams of magnesium over a Bunsen burner for several minutes until it reacts with oxygen in the air. Then you weigh the resulting product and see that it is now 53 grams. How does this happen without breaking the Law of Conservation of Mass?
Answer:
The mass was there all along, it was just in the air. The weight of the oxygen from the air is not weighed in the beginning, only at the end as part of the product, making it seem like there is a total mass change.
Sample of carbonate rock is a mixture of CaCO3 and MgCO3. The rock is Analyzed in a laboratory and the results are recorded in the table above. Which columns in a table provide all the information necessary to determine the mole ratio of analyzed in a laboratory and the results are recorded in the table above. Which columns in a table provide all the information necessary to determine the mole ratio of Ca to Mg in the rock
Answer:
You need the mass of Mg and Ca in the sample and their molar masses
Explanation:
Its the only answer that made sense because using those 4, can give you their ration
The Columns in the table that provides the information necessary for the calculating the mole ratio of Ca to Mg are columns ; 3, 4, 6, and 7
Although some data related to your question is missing attached below is the missing data
Determining the mole ratio of Ca to Mg
Ca : Mg
mass of Ca / molar mass : mass of Mg / Molar mass
( 36.1 / 40.1 ) : ( 2.4 / 24.3 )
9.14 : 1
∴ The mole ratio of Mg to Ca
≈ 1 : 9
Where: Column 3 = Mass of Mg in the sample ( g )
Column 4 = mass of Ca in the sample ( g )
Column 6 = Molar mass of Mg ( g/mol )
Column 7 = molar mass of Ca ( g/mol )
Hence the Mole ratio of Mg to Ca = 1 : 9
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wich element is likely to be the most reactive? bromine (Br) chlorine (Cl) fluorine (F) iodine (I)
most reactive among them is fluorine because it is the most electronegative element
Answer:
fluorine (F)
Explanation:
I took the test on edge
List the types of electromagnetic radiation in order of increasing frequency.
Answer:
In order of increasing frequency and decreasing wavelength these are: radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays and gamma rays........... ᕕ( ᐛ )ᕗ
..
15.0 g of water is heated from 5 °C up to 37 °C. How much energy is absorbed by
the water? (The specific heat of liquid water is 4.184 J/g °C.)
Answer:
See the answer
1) 15.0 g of water is heated from 5 °C up to 37 °C. How much energy is absorbed by the water? (The specific heat of liquid water is 4.184 J/g°C.)
2)How many joules of energy is required to bring a five-pound (1 pound = 454 g) bag of ice from its freezer temperature at -20.0°C up to 0°C? The specific heat of ice is 2.10 J/g×°C.
3) A 50.0 mg tissue sample is taken from a patient for diagnosis. While waiting for testing, the sample is stored in a -80.0°C freezer. How much energy is released when the sample is cooled from 20.0°C down to the freezer temperature? You may assume the specific heat of the tissue sample is 3.47 J/g×K.
A beaker can hold 200 cm3 of water. When it's empty, how
many liters are needed to refill it?
L
Answer:
[tex]V=0.200L[/tex]
Explanation:
Hello,
In this case, since the volumetric capacity of the beaker is 200 cm³, by considering that 1000 cm³ equals 1 L, the liters are then computed via the following unit conversion:
[tex]V=200cm^3*\frac{1L}{1000cm^3}\\ \\V=0.200L[/tex]
Best regards.
When 3.0 g of water is warmed from 10.0∘C to 80.0∘C, how much heat energy is needed? Specific heat for water is 4.186Jg(∘C).
Answer:
Specific heat is the amount of heat energy required to raise the temperature of substance by, the units for specific heat is, each element have particular fixed specific heat.
The heat energy change can be obtained by the formula

Temperature change can be represented by 

If we know the specific heat of substance then we can easily calculate the heat energy change of the substance
Which statement best describes chemical properties of matter? Chemical properties, such as density, must be observed when a substance is in its natural state at room temperature and normal atmospheric pressure. Chemical properties, such as reactivity, must be observed when a substance is in its natural state at room temperature and normal atmospheric pressure. Chemical properties, such as combustibility, are generally observed as the identity of a substance changes and one or more new substances form. Chemical properties, such as boiling point, are generally observed as the identity of a substance changes and one or more new substances form.
Answer:
Chemical properties, such as combustibility, are generally observed as the identity of a substance changes and one or more new substances form.
Explanation:
Chemical properties, such as combustibility, are generally observed as the identity of a substance changes and one or more new substances form. Hence, option C is correct.
What are the chemical properties of matter?Chemical properties are properties that can be measured or observed only when matter undergoes a change to become an entirely different kind of matter.
Substances made of wood, such as paper and cardboard, are also flammable.
Chemical properties are properties that can be measured or observed only when matter undergoes a change to become an entirely different kind of matter.
They include reactivity, flammability, and the ability to rust.
Hence, option C is correct.
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How are the Celsius, Kelvin, and Fahrenheit scales similar? How are they different?
celcius and Fahrenheit are the same at -40 degrees since the scales converge . celcius and Kelvin become Equal at high temperatures as the difference. of 273. 15 between them gets lost in the noise . 0 degree Celsius is Equal to 32degrees Fahrenheit.
The vapor pressure of carbon disulfide is 355.6 torr at 25°C. What is the vapor pressure of a solution prepared by dissolving 10.60 g naphthalene (C10H8, Molar Mass = 128.2 g/mol) in 155 mL CS2 liquid (Molar Mass = 76.14 g/mol, density = 1.261 g/mL)? Assume the solution obeys Raoult's law, and treat naphthalene as a nonvolatile solute.
Answer:
344.5764 torr
Explanation:
Molar mass of naphthalene = 128.2g/mol
Mass of naphthalene = 10.60 g
Carbon disulfide:
Molar mass= 76.14g/mol ;
volume = 155mL ;
density = 1.261 g/mL
Vapour pressure = 355.6 torr
Number of moles = mass / molar mass
CS2:
Mass = density × volume
Number of moles = (density × volume) / molar mass
Number of moles = (1.261 * 155) / 76.14 = (195.455 / 76.14) = 2.567 moles of CS2
Number of moles of C8H10:
Number of moles = 10.60 / 128.2 = 0.083 C8H10
Total number of moles :
2.567 + 0.083 = 2.65 moles
Mole fraction of each compound in solution :
CS2 :
2.567 / 2.65 = 0.969
C8H10:
0.083 / 2.65 = 0.031
According to Raoult's:
Psolution = Xsolvent × Posolvent
CS2 = solvent
Xsolvent = Mole fraction of solvent
Posolvent = Vapour pressure of pure solvent
Psolution = 0.969 × 355.6 torr = 344.5764 torr
The vapor pressure of the solution would be as follows:
[tex]344.5764[/tex] torr
Given that,
Vapor pressure of Carbon Disulfide [tex]= 355.6[/tex] torr
[tex]volume = 155mL ;[/tex]
[tex]density = 1.261 g/mL[/tex]
Naphthalene's mass [tex]= 10.60 g[/tex]
Naphthalene's molar mass [tex]= 128.2g/mol[/tex]
Now,
We know that
Number of moles [tex]= mass/molar mass[/tex]
Mass [tex]= density[/tex] × [tex]volume[/tex]
[tex]Number of moles =[/tex] [tex](density[/tex] × [tex]volume) / molar mass[/tex]
So,
Number of moles of Carbon Disulfide [tex]= (1.261[/tex] × [tex]155) / 76.14[/tex]
[tex]= (195.455 / 76.14)[/tex]
[tex]= 2.567[/tex] moles of Carbon Disulfide
Number of moles of Naphthalene:
Number of moles [tex]= 10.60 / 128.2[/tex]
[tex]= 0.083[/tex]
Now,
Total number of moles :
[tex]2.567 + 0.083[/tex]
[tex]= 2.65[/tex] moles
Mole fraction of each compound in solution :
Carbon Disulfide:
2.567 / 2.65
[tex]= 0.969[/tex]
Naphthalene
0.083 / 2.65
[tex]= 0.031[/tex]
According to Raoult's:
P[tex]solution = Xsolvent[/tex] × [tex]Posolvent[/tex]
Carbon Sulfide = Solvent
[tex]Xsolvent =[/tex] Mole fraction of solvent
[tex]Posolvent =[/tex] Vapour pressure of the pure solvent
[tex]Psolution[/tex] [tex]= 0.969[/tex] × [tex]355.6 torr[/tex]
[tex]= 344.5764[/tex] torr
Thus, "[tex]344.5764[/tex] torr" is the correct answer.
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The compound 2-hydroxybiphenyl (o-phenylphenol) boils at 286 °C under 101.325 kPa and at 145 °C under a reduced pressure of
14 Torr. Calculate the value of the molar enthalpy of vaporization. Compare this value to that given in the CRC Handbook.
Answer: [tex]\Delta H_{vap}[/tex] = 55.1 kJ/mol
Explanation: Molar Enthalpy of Vaporization([tex]\Delta H_{vap}[/tex] ) is the energy needed to change 1 mol of a substance from liquid to gas at constant temperature and pressure.
For the 2-hydroxybiphenyl, there two temperatures and 2 pressures. In this case, use Clausius-Clapeyron equation:
[tex]ln\frac{P_{2}}{P_{1}}=\frac{\Delta H_{vap}}{R} (\frac{1}{T_{1}}-\frac{1}{T_{2}} )[/tex]
[tex]\Delta H_{vap}[/tex] is in J/mol:
1) Temperature in K
[tex]T_{1}=[/tex] 286 +273 = 559K
[tex]T_{2}[/tex] = 145 + 273 = 418K
2) Both pressure in Pa
[tex]P_{1}[/tex] = 101325Pa
[tex]P_{2}[/tex] = 14*133 = 1862Pa
Since molar enthalpy is in Joules, gas constant R is 8.3145J/mol.K
Replacing into the equation:
[tex]ln\frac{1862}{101325}}=\frac{\Delta H_{vap}}{8.3145} (\frac{1}{559}-\frac{1}{418} )[/tex]
[tex]ln(0.0184)=\frac{\Delta H_{vap}}{8.3145} (\frac{141}{233662} )[/tex]
[tex]\Delta H_{vap}=\frac{-3.9954*1942782.7}{-141}[/tex]
[tex]\Delta H_{vap}=55051.02[/tex]
[tex]\Delta H_{vap}=55051.02[/tex]
[tex]\Delta H_{vap}=55.1[/tex] kJ/mol
Using those values, molar enthalpy is 55.1 kJ/mol
Comparing to the CRC Handbook, which is [tex]\Delta H_{vap}=71[/tex] kJ/mol:
[tex]\frac{55.1}{71}[/tex] = 0.78
The calculated value is 0.78 times less than the CRC Handbook.
What percentage of light hits Earth’s surface directly?
3 percent
5 percent
31 percent
47 percent
Answer: yall trust me on this one, i took one for the team. The answer is "C" or you can say 31 percent. boys get me 50 thanks.
Explanation:
The percentage of sunlight that hits the Earth's surface directly is 31 percent. The correct option is C.
What is sunlight?Sunlight is the electromagnetic radiation transferred by the sun.
The sun is 93 million away from the earth, so it takes eight and half minutes to reach the sunlight to the earth.
Only 30 to 34 percent of light reaches the earth, and the remaining lights are reflected back by clouds and the earth itself.
Thus, the correct option is C, 31 percent.
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The formula for a compound containing sodium and oxide ions would contain... This
compound would have an overall ... charge.
Answer:
Explanation:
the formula of the compound containing sodium and oxide ion is
NaOH the charge on sodium is partial positive and the charge on hydroxide ion is partial negative
another compound containing sodium and oxide ion is Na2O here the charge on sodium oxide is neutral
What property of matter is a
measure of the force of
gravity on an object?
Answer:
No matter where that object is in the vast universe, it will have the same mass. Weight, on the other hand, is a measure of how much gravitational force is exerted on an object.