Answer:
he mass in grams of one mole of substance is called molar mass. Each element has its own unique molar mass. For example, carbons molar mass is 12.011 g/mol, and magnesium's molar mass is 24.3050 g/mol. To see why these elements have different molar masses, we need to remember that the atoms of different elements contain different numbers of protons, neutrons, and electrons, so they have different masses. The atomic masses given in the periodic table inside the front cover of this book represent the different weighted average masses of the naturally occurring atoms of each element. Different atomic masses lead to different molar masses.
For example, the atomic mass of magnesium (24.3050) shows us that the average mass of magnesium atoms is about twice the average mass of carbon atoms (12.011), so the mass of 6.022 x 1023 magnesium atoms (the number of atoms in 1 mole of magnesium) is about twice the mass of 6.022 x 1023 carbon atoms (the number of atoms in 1 mole of carbon). Thus the molar mass of magnesium is 24.3050 g/mol, compared to carbons molar mass of 12.011 g/mol.
Explanation:
Graphene is made of pure _______________.
Answer:
Graphene is made of pure carbon.
Explanation:
It is a material in which the carbon atoms are arranged in a single layer, creating a honeycomb pattern. It should be stressed that this layer of carbon is only one atom thick, although some authors consider up to ten layers of carbon to be graphene.
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HELP PLEASE 40.0 grams of salt are dissolved in 100. grams of water. The solution is how many grams?
Answer:
The mass of the solution is 140 grams.
Explanation:
The mass of the solution is given by the sum of the solute's mass and the solvent's mass:
[tex] m_{sol} = m_{ste} + m_{svt} [/tex]
Where:
[tex] m_{sol} [/tex]: is the mass of the solution
[tex]m_{ste}[/tex]: is the mass of the solute
[tex]m_{svt} [/tex]: is the mass of the solvent
The solute is the salt (40.0 g) and the solvent is the water (100 g), so:
[tex] m_{sol} = m_{ste} + m_{svt} = 40 g + 100 g = 140 g [/tex]
Therefore, the mass of the solution is 140 grams.
I hope it helps you!
2. A sample of helium gas has a volume of 200.0 mL at 0.960 atm. What pressure, in atmospheres, is needed to reduce the volume at constant tem-perature to 50.0 mL?
Answer:
3.840 atm
Explanation:
We use Boyle's law, which relates the pressure (P) and the volume (V) of a gas at a constant temperature. The change from initial P and V (P₁ and V₁) to final P and V (P₂ and V₂) is expressed as:
P₁V₁ = P₂V₂
We have the following data:
P₁= 0.960 atm
V₁= 200.0 mL
V₂ = 50.0 mL
Thus, we introduce the data in the equation and calculate the final pressure P₂:
P₂ = P₁V₁/V₂= (0.960 atm x 200.0 mL)/50.0 mL = 3.840 atm
Therefore, a pressure of 3.840 atm is needed to reduce the volume of the gas from 200.0 mL to 50.0 mL.
This attached picture !!
Does anyone have any idea what this means lol
Answer:
29.42 Litres
Explanation:
The general/ideal gas equation is used to solve this question as follows:
PV = nRT
Where;
P = pressure (atm)
V = volume (L)
n = number of moles (mol)
R = gas law constant (0.0821 Latm/molK)
T = temperature (K
According to the information provided in this question;
mass of nitrogen gas (N2) = 25g
Pressure = 0.785 atm
Temperature = 315K
Volume = ?
To calculate the number of moles (n) of N2, we use:
mole = mass/molar mass
Molar mass of N2 = 14(2) = 28g/mol
mole = 25/28
mole = 0.893mol
Using PV = nRT
V = nRT/P
V = (0.893 × 0.0821 × 315) ÷ 0.785
V = 23.09 ÷ 0.785
V = 29.42 Litres
You need to prepare .200M solution of hydrochloric acid (HCl). If you took out .830ml of the 12.0M stock solution. How much water must you add to make the .200M diluted solution?
Answer:
You must add 48.97 mL of water to make the 0.200 M diluted solution.
Explanation:
In chemistry, dilution is the reduction in concentration of a chemical in a solution. In other words, it is the process of reducing the concentration of solute in solution, simply adding more solvent to the solution.
In a dilution, the quantity or mass of the solute is not changed but only that of the solvent. As only solvent is being added, by not increasing the amount of solute the concentration of the solute decreases.
The expression for the dilution calculations is:
Cinitial* Vinitial = Cfinal* Vfinal
In this case:
Cinitial= 12 MVinitial= 0.830 mLCfinal= 0.200 MVfinal= ?Replacing:
12 M*0.830 mL= 0.200 M*Vfinal
Solving:
[tex]Vfinal=\frac{12 M*0.830 mL}{0.200 M}[/tex]
Vfinal= 49.8 mL
Since 0.830 mL is the volume you initially have of HCl, the amount of water you must add is:
49.8 mL - 0.830 mL= 48.97 mL
You must add 48.97 mL of water to make the 0.200 M diluted solution.
answer asap pls i give brainliest
Answer:
B. Revolution is a planet's movement around the sun causing four seasons the occur. Rotation is the spinning of the planet on its axis causing day and night.
IS ANYONE GOOD AT CHEMISTRY?! like frr.
I need help
Question 26 of 33
How many energy levels contain electrons in an atom of calcium (Ca)?
The Periodic Table
A. Three
B. Four
C. One
D. Two
Answer:
B
Explanation:
four electron in atom in cal
How many moles of calcium oxide are formed when 3 moles of calcium react with oxygen?
Answer:
3 moles of calcium oxide are formed
Explanation:
Based on the reaction of Calcium Ca, with oxygen, O₂, to produce calcium oxide, CaO is:
2Ca + O₂ → 2CaO
where 2 moles of calcium produce 2 moles of Calcium oxide.
That means, if 3 moles of Ca react in presence of oxygen:
3 moles of calcium oxide are formed
how many torr is 2.7 atm?
2.7 atm = ? torr
Answer:
2.7 atm = 2052 torr
I hope this helps you.
Answer:
2052 torr
Explanation:
Multiply 2.7 atm by the conversion factor to torr which is 760 torr = 1 atm
Which type of star has the greatest temperature on the HR diagram? Question 7 options: Red Supergiants Main Sequence White Dwarfs Red Giants
Answer:
Red Super Giants
Explanation:
Beacuse of the of their size, the core temperature is more hotter then White Dwarfs and Red Giants.
Answer:
Red Super Giants
Explanation:
Their core is the hottest.
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How many grams of sodium phosphate are formed by the reaction of 10 g of sodium with phosphoric acid?
Answer:
23.8g of sodium phosphate are formed
Explanation:
Based on the reaction of sodium, Na, with phosphoric acid, H₃PO₄:
3Na + H₃PO₄ → Na₃PO₄ + 3/2 H₂
3 moles of sodium produce 1 mole of sodium phosphate
To solve this question we must find the moles of sodium in 10g. Using the chemical reaction we can find the moles -And the mass- of sodium phosphate produced, as follows:
Moles Na -Molar mass: 22.99g/mol-
10g * (1mol / 22.99g) = 0.435 moles Na
Moles Na₃PO₄:
0.435 moles Na * (1mol Na₃PO₄ / 3mol Na) = 0.145 moles Na₃PO₄
Mass Na₃PO₄ -Molar mass: 163.94g/mol-
0.145 moles Na₃PO₄ * (163.94g/mol) =
23.8g of sodium phosphate are formedWhat mass of ethanol can you boil with 9986 J if the heat of vaporization is 854 J/g?
Answer:
51,069.2 J
Explanation:
Use the heat of vaporization formula:
q=m⋅Hv
The heat of vaporization of ethanol is 854 J/g (given in the question), which means that it takes 854 joules of energy to vaporize one gram of ethanol.
Since we have 59.8 grams of ethanol, plug 59.8 into the formula and multiply by 854.
q = (59.8) (854)
q= 51069.2 J
hope this helped somehow
(4x972)+(76.4x29.3)-(12x7)
solve using significant figures please ASAP
A 1.0 g sample of which substance contains the largest
number of molecules?
Answer:
Hydrogen (since this is all the info I'm working with)
Explanation:
Since we need to know how which substance has the most amount of molecules, we would need to look at the Atomic masses of these elements. Hydrogen has an atomic mass of 1.01g/mol whereas something like oxygen has an atomic mass of 16.00g/mol. Judging this, we can determine since a mole is made up of 6.02*10^23 molecules(Avogadro's number), and we have 1/1.01grams of hydrogen, we can deduce that Hydrogen would contain the largest amount of molecules
What is the difference between an imprint and an impression?
Answer:
As nouns the difference between impression and imprint
is that impression is the indentation or depression made by the pressure of one object on or into another while imprint is an impression; the mark left behind by printing something.
The term imprint is defined as to mark by or as if by pressure and the term impression is defined as the effect produced by impressing.
What is the difference between an imprint and an impression?The difference between an imprint and an impression is that the imprint is the mark left behind when anything is printed, whereas the impression is the indentation or depression caused by the pressure of one object against or into another.
While a shoe won't make an impression in loose sand, it will on a hard surface like concrete or linoleum. These imprints or impressions might be contrasted with the shoe of a suspect or the tire of a car to see if they belong to the same object.
Thus, The term imprint is defined as to mark by or as if by pressure and the term impression is defined as the effect produced by impressing.
To learn more about the imprint and the impression, follow the link;
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Organisms trying to get the same resource.
Mutualism
Predation
Competition
Symbiosis
Which is composed of alkenes? welding torch fuel polystyrene cups propane gas degreaser containing hexane
Answer:
welding torch fuel
Explanation:
Alkenes are chemical compounds formed by a carbon atom and a hydrogen atom. They have an open chain with double bonds between two carbon acts. They are widely used in the composition of fuels, such as welding torch fuel and have as main characteristics the solubility in solvents, the insolubility in water, high melting and boiling point and the absence of colors.
Welding torch fuel is composed of alkenes. The alkenes comprise a series of compounds that are composed of carbon and hydrogen atoms with at least one double bond in the carbon chain.
What are alkenes?Alkenes are a homologous series of hydrocarbons that contain a carbon-carbon double bond.
The number of hydrogen atoms in an alkene is double the number of carbon atoms, so they have the general formula [tex]C_nH _2 _n[/tex].
For example, the molecular formula of ethene is [tex]C _2 H _4[/tex] , while for propene it is [tex]C _3 H _6[/tex].
Alkenes are chemical compounds formed by a carbon atom and a hydrogen atom.
They have an open chain with double bonds between two carbon acts.
They are widely used in the composition of fuels, such as welding torch fuel and have as main characteristics the solubility in solvents, the insolubility in water, high melting and boiling point and the absence of colors.
Hence, the Welding torch fuel is composed of alkenes.
Learn more about the alkenes here:
https://brainly.com/question/13910028
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6
Use the image of an element square to answer the following
questions:
C
Carbon
12.01
What does the 6 in the upper left
represent?
What does the 12.01 represent?
Answer:
the 6 stands for the atomic number
the 12.01 stands for the atomic mass
What is the molarity of a 511 ml solution containing
205 mg of NH3?
401M 0.0235M 0.401M 0.0000235M
As time passes, which of these is decreasing?
es )
A)
amplitude
B)
crest
trough
D)
wavelength
Answer:
Wavelength (D)............
Answer:
A
Explanation:
the amplitude is measured from the dotted line to the top of the crest. Looking at the picture the amplitude gets smaller
A 45.0 cm3 sample of gas is heated from 280. K to 315 K. What is the new volume of the gas sample?
Answer:
50.63 cm³
Explanation:
Using Charles law equation as follows:
V1/T1 = V2/T2
Where;
V1 = initial volume (cm³)
V2 = final volume (cm³)
T1 = initial temperature (K)
T2 = final temperature (K)
According to the question, V1 = 45.0 cm³, V2 = ?, T1 = 280 K, T2 = 315 K
Using; V1/T1 = V2/T2
45/280 = V2/315
Cross multiply
45 × 315 = 280 × V2
14175 = 280V2
V2 = 14175 ÷ 280
V2 = 50.625
V2 = 50.63 cm³
Calculate the Density of the substances below to determine if they will float or sink in water.
Mass
Volume
Density
Float or Sink
45. Substance 1
90 ml
46. Substance 2
450 grams
35 grams
24 grams
70 ml
47. Substance 3
12 ml
Explanation:
If the density of the object is more than that of water, it will sink. Otherwise it will float. The density of water is 1 g/mL.
Substance 1,
Mass, m = 450 g, Volume, V = 90 mL
Density = mass/volume
So,
[tex]d_1=\dfrac{450}{90}\\\\=5\ g/mL[/tex]
It will sink.
Substance 2,
Mass, m = 35 g, Volume, V = 70 mL
Density = mass/volume
So,
[tex]d_2=\dfrac{35}{70}\\\\=0.5\ g/mL[/tex]
It will float.
Substance 3,
Mass, m = 24 g, Volume, V = 12 mL
Density = mass/volume
So,
[tex]d_3=\dfrac{24}{12}\\\\=2\ g/mL[/tex]
It will sink.
Solve for 1. Enter the solutions from least to greates (x + 3)2 - 4= 0 lesser ,greater
Answer:
Explanation:
If you would like to solve 1/(x + 3) = (x + 10)/(x - 2), you can do this using the following steps:
1/(x + 3) = (x + 10)/(x - 2)
1 * (x - 2) = (x + 10) * (x + 3)
x - 2 = x^2 + 3x + 10x + 30
0 = x^2 + 13x + 30 - x + 2
0 = x^2 + 12x + 32
0 = (x + 8) * (x + 4)
1. x = -8
2. x = -4
A gas of certain mass occupies volume of 1.2 L at 37°C and 3 atm. At what temperature will the volume and pressure of this gas become one-third of their initial values?
Answer: At a temperature of 34.44 K the volume and pressure of this gas become one-third of their initial values.
Explanation:
Given : [tex]V_{1}[/tex] = 1.2 L, [tex]T_{1} = 37^{o}C = (37 + 273) K = 310 K[/tex]
[tex]P_{1}[/tex] = 3 atm, [tex]V_{2} = \frac{1.2}{3} = 0.4 L[/tex] , [tex]P_{2} = \frac{3}{3} = 1 atm[/tex]
Formula used to calculate the final temperature is as follows.
[tex]\frac{P_{1}V_{1}}{T_{1}} = \frac{P_{2}V_{2}}{T_{2}}[/tex]
Substitute the values into above formula as follows.
[tex]\frac{P_{1}V_{1}}{T_{1}} = \frac{P_{2}V_{2}}{T_{2}}\\\frac{3 atm \times 1.2 L}{310 K} = \frac{1 atm \times 0.4 L}{T_{2}}\\T_{2} = \frac{1 atm \times 0.4 L \times 310 K}{3 atm \times 1.2 L}\\= \frac{124}{3.6} K\\= 34.44 K[/tex]
Thus, we can conclude that the final temperature is 34.44 K.
Which type of star has the greatest temperature on the HR diagram? Question 7 options: Red Supergiants Main Sequence White Dwarfs Red Giants
Answer:
Red supergiant
Explanation:
Their core is the hottest.
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What are the 4 main layers of the Earth's Atmosphere?
Answer:
troposphere, stratosphere, mesosphere, thermosphere and exosphere
Explanation:
Calculate the heat gained when 20.1 g ice at - 12.5 degrees * C is heated to liquid water 55.2 degrees * C
Answer:
66.8
Explanation:
Calculate that is what I did.
have a good day!
Which statement explains why carbon-14 dating cannot be used to date ancient rocks?
O Carbon-14 decays at a varying rate.
O Carbon-14 decays quickly leaving the amount too small to measure.
O Carbon-14 can be used only to date the remains of organisms.
O Carbon-14 has a half-life that is much longer than potassium.
Answer: Carbon-14 decays quickly leaving the amount too small to measure.
Explanation:
Answer:
b
Explanation:
i did it