12. How many moles of atoms are present in 154 g of Na2O?
A) 2.48 mol
B) 7.45 mol
C) 51.3 mol
D) 0.827 mol
Answer:
[tex]\boxed {\boxed {\sf A. \ 2.48 \ mol \ Na_2O}}[/tex]
Explanation:
We are asked to convert an amount in grams to moles. To do this, we use the molar mass. This is the number of grams in one mole of a substance. It is the same value numerically as the atomic mass on the Periodic Table, however the units are grams per mole, not atomic mass units.
Look up the molar masses for the individual elements.
Sodium (Na): 22.9897693 g/mol Oxygen (O): 15.999 g/molLook back at the formula: Na₂O. Notice there is a subscript of 2 after sodium. This means there are 2 atoms of sodium in every molecule, so we have to multiply sodium's molar mass by 2 before adding oxygen's.
Na₂O: 2(22.9897693 g/mol)+ 15.999 g/mol = 61.9785386 g/molSet up a ratio using the molar mass.
[tex]\frac {61.9785386 \ g \ Na_2O}{1 \ mol \ Na_2O}[/tex]
Multiply by the given number of grams.
[tex]154 \ g \ Na_2O*\frac {61.9785386 \ g \ Na_2O}{1 \ mol \ Na_2O}[/tex]
Flip the ratio so the grams of sodium oxide can cancel each other out.
[tex]154 \ g \ Na_2O*\frac {1 \ mol \ Na_2O}{61.9785386 \ g \ Na_2O}[/tex]
[tex]154 *\frac {1 \ mol \ Na_2O}{61.9785386 }[/tex]
[tex]\frac {154}{61.9785386 } \ mol \ Na_2O[/tex]
[tex]2.48473106141 \ mol \ Na_2O[/tex]
The original measurement of grams given has 3 significant figures, so our answer must have the same. For the number we calculated, that is the hundredth place.
2.48473106141The 4 in the thousandth place tells us to leave the 8.
[tex]2.48 \ mol \ Na_2O[/tex]
There are 2.48 moles of sodium oxide in 154 grams, so choice A is correct.
A sample of unknown pressure occupies 0.776L at a temperature of 298K. The sample of gas is then tested under known
conditions and has a pressure of 32.6 kPa and occupies 0.664L at 303K. What was the original pressure of the gas?
A. 27.43 kPa
B. 38.62 kPa
C. 58.73 kPa
D. 84.11 kPa
Answer:
27.43 kPa (Option A)
Explanation:
We can solve this by the use of the Ideal Gases Law.
P . V = n . R . T
As n and R are constant, we avoid them from the equation so:
P₁ . V₁ / T₁ = P₂ . V₂ / T₂
P₁ . 0776L / 298K = 32.6 kPa . 0.664L / 303K
P₁ . 0776L / 298K = 0.0714 kPa .L/K
P₁ . 0776L = 0.0714 kPa .L/K . 298K
P₁ = 21.289 kPa.L / 0.776L
P₁ = 27.43 kPa
12. Which organelle is found in plant and animal cells and is involved in making cellular energy from
respiration?
Answer:
The mitochondria is the organelle found in plant and animal cells and is involved in making cellular energy from respiration.
Explanation:
Question 2
1 pts
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A compound is 31.1 % S, the rest is chlorine. The compound has a molecular mass of 205.94 amu.
What is its molecular formula?
Explanation:
its hard to explain unless we know what the question fully asks..
What energy transformations occur in a hot air balloon?
Answer:
: kinetic energy is the energy transformation that occurs in a hot balloon.
Explanation:
Hot air balloons use a propane burner that converts chemical energy to thermal energy. The hot air is less dense than than the colder air and it lifts the balloon
What happens to the rate if the concentration of 1-iodopropane remains the same and the concentration of sodium hydroxide is doubled
Answer:
The rate of reaction is doubled
Explanation:
The reaction between 1-iodopropane and sodium hydroxide is an SN2 reaction. This reaction takes place by a concerted mechanism and the hydroxide ion is the nucleophile.
In an SN reaction, the reaction is second order because the rate of reaction depends both on the concentration of the alkylhalide and that of the nucleophile. Hence, when the concentration of 1-iodopropane (the alkyl halide) is held constant and the concentration of hydroxide ion (the nucleophile) is doubled, the rate of reaction is doubled since;
Rate =k [1-iodopropane] [OH^-]
calculate the percentage of CL in AL(CLO3)3
Answer:
46.41%
Explanation:
Find the total r.m.m of AL(CLO3)3 put it equals to 100%.....The take 106.5,the total r.m.m of Cl and find the missing which is the percentage by cross multiplication
The weight for this compound is 74. what is the molecular formula
Explanation:
ur question is incomplete what elements make the compound and we talk of mass not weight and what are the units kjmol ,grams ,kgs
3.
Calculate the mass in grams needed to have 2.65 x 1022 atoms of calcium.
८८
2.65 x 10²
Answer:
[tex]=1.76gCa[/tex]
Explanation:
Hello there!
In this case, according to the given atoms of calcium, it is possible to calculate the mass of this element by considering that the definition of mole is in terms of atoms and also the atomic mass of calcium:
[tex]1molCa=6.022x10^{23}atoms Ca=40.08gCa[/tex]
In such a way, by considering the following setup, we can obtain:
[tex]=2.65x10^{22}atomsCa*\frac{1molCa}{6.022x10^{23}atoms} *\frac{40.08gCa}{1molCa}\\\\=1.76gCa[/tex]
Best regards!
Which lava contains a lot of water
Answer:
i think its magma ajani i looked it up... and chelsey said u had corona so if its true hope u get better bro
Explanation:
AB G C F G Y OBLAD
E Y RESISTANCE
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UK V WY FHB CAET
HAIR SD GH J K LE
CMTU ONHULG EA
A OY S HAV CFH RM
RMOTION RS FAW
AYKY OHBWIST R
P PULL DOWN AEE
help me finding six words
observation made when lead oxide passes through hydrogen gas
Answer:
a gray substance and colourless liquid
Explanation:
lead oxide is reduced to lead while hydrogen is oxidized to water
A bottle containing air is initially at a temperature of 33 degrees C and a pressure of 0.81 atm. After being placed in the freezer, the final temperature is 1 degrees C. What is the final pressure ?
Answer:
The final pressure is 0.725 atm.
Explanation:
Gay Lussac's Law establishes the relationship between pressure and temperature of a gas when the volume is constant. This law says that when there is a constant volume, as the temperature increases, the pressure of the gas increases. And when the temperature is decreased, the pressure of the gas decreases. That is, pressure and temperature are directly proportional quantities.
Mathematically, Gay-Lussac's law states that, when a gas undergoes a constant volume transformation, the quotient of the pressure exerted by the gas temperature remains constant:
[tex]\frac{P}{T} =k[/tex]
When analyzing an initial state 1 and a final state 2, the following is satisfied:
[tex]\frac{P1}{T1} =\frac{P2}{T2}[/tex]
In this case:
P1= 0.81 atmT1= 33 C= 306 KP2= ?T2= 1 C= 274 KReplacing:
[tex]\frac{0.81 atm}{306 K} =\frac{P2}{274 K}[/tex]
Solving:
[tex]P2=274 K*\frac{0.81 atm}{306 K}[/tex]
P2= 0.725 atm
The final pressure is 0.725 atm.
According to the theory of plate tectonics,
which of the following statements is true?
A Earthquakes and volcanoes con change Earth's surface, but the
overall locations of land and ocean do not change over time.
B. Continents have grown, shrunk, and
moved over the course of Earth's history.
C. The ratio of ocean to land on Eorth has been
pretty much the same throughout Earth's history,
Consider the following ionization reaction.
HNO3 (aq) + H20 () = NO,- (aq) + H2O* (aq)
a)
Define acid and base according to Bronsted-Lowry, and give an example of each.
(3 marks)
b) Identify all acids and its conjugate base pairs from the above equation.
(2 marks)
Answer:
See explanation
Explanation:
According to Bronsted-Lowry, an acid is a proton donor while a base is a proton acceptor.
Hence, if we consider the reaction above, we will notice that for each base there is a conjugate acid and for each acid there is a conjugate base.
For the acid HNO3, its conjugate base is NO3^- while for the acid H3O^+, its conjugate base is H2O.
1. Given the following unbalanced equation:
Al(SO3)3 + NaOH
---> Na2SO3 + Al(OH)3
If you start with 389.4 grams of Al(SO3)3 and 200 grams of NaOH ?
Identify the limiting reactant:
Identify the reactant in excess and by how much:
How many grams of Na2SO, will be produced:
If you perform the same reaction but get 212.4 grams of Na2SO3, what is
your percent yield?
Answer:
Limting reactant: NaOH
Excess reactant: Al₂(SO₃)₃ by 104.9 grams.
315 g of Na₂SO₃ are produced in the reaction
67.4 % is the percent yield.
Explanation:
Balaced equation is:
Al₂(SO₃)₃ + 6NaOH → 3Na₂SO₃ + 2Al(OH)₃
We convert the mass of each reactant to moles, to identify the limiting reactant:
389.4 g . 1mol/ 342.15g = 1.14 moles of sulfite
200 g . 1mol / 40g = 5 moles
1 mol of aluminum sulfite react to 6 moles of NaOH, according to stoichiometry.
If we have 1.14 moles of sulfite, we need (1.14 . 6)/1 = 6.82 moles
We only have 5 mol of NaOH, so this is the limiting reactant.
Then the aluminum sulfite is the excess.
6 moles of NaOH react to 1 mol of sulfite
Then, 5 moles of NaOH may react to (5 . 1)/6 = 0.83 moles.
1.14 mol - 0.83 mol = 0.31 moles remains after the reaction goes complete.
We convert to mass: 0.31 mol . 342.15g/mol = 104.9 g
Then, we work with the limiting reactant. Stoichiometry is 6:3 (2)
6 moles of NaOH can produce 3 moles of sodium sulfite
Then 5 moles will produce (5 . 3)/6 = 2.5 moles
We convert moles to mass: 2.5 mol . 126 g/mol = 315 g.
Percent yield = (Yield produced/Thoeretical yield) . 100
Percent yield = (212.4g /315g) . 100 = 67.4 %
Solid A at 80°C is immersed in liquid B at 60°C. Which statement correctly describes the energy changes between A and B?
Heat energy will be released by solid A which will then be absorbed by liquid B.
What is heat energy?
These little particles vibrate back and forth or run into each other constantly. All matter contains a type of energy known as heat (or thermal) energy, which is produced by the movement of particles.
Particle energy increases with temperature. It is possible for some of this energy to be transferred to cooler particles. For instance, in the gas state, when a fast-moving particle strikes a slower-moving particle, some of the energy from the collision is transferred to the slower-moving particle, increasing its speed.
A region of high energy will gradually spread throughout the material as a result of billions of moving particles colliding with one another until thermal equilibrium is established.
Therefore, heat energy will be released by solid A which will then be absorbed by liquid B.
Read more about heat energy, here
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Which of the following patients should be admitted as an inpatient at a
hospital?
A. Katie's having her tonsils removed and will be able to go home
shortly after she wakes up from surgery.
B. Phil's having his blood sugar tested and having his annual
physical
c. Salvatore's having a hip transplant and will need to be closely
monitored for a week.
D. Chen's having chest X-rays taken to determine if he has a broken
rib.
SUBMIT
when iron rust it reacts with nitrogen from the air
true or false
it is false it reacts with oxygen
give brainliest if right
To solve such this we must know the concept of oxidation reaction. Therefore, the given statement is incorrect. When iron rust it reacts with oxygen from the air.
What is chemical reaction?Chemical reaction is a process in which two or more than two molecules collide in right orientation and energy to form a new chemical compound. The mass of the overall reaction should be conserved. There are so many types of chemical reaction reaction like combination reaction, double displacement reaction.
In oxidation reaction, one of the element of the given compound oxidises to its higher oxidation state. Rusting is an example of oxidation reaction. The balanced equation for the rusting reaction can be given as
4Fe + 3O[tex]_2[/tex] + 6H[tex]_2[/tex]O → 4Fe(OH)[tex]_3[/tex]
Therefore, the given statement is incorrect.
Learn more about the chemical reactions, here:
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What is the proper formula for vanadium (iv) percholrate?
Answer:VO(ClO4)3 i'm sure this is it
Explanation:
According to the data, which part is described by the letter K?
a
constellation
b
galaxy
c
meteoroid
d
planet
Answer:
C meteoroid
Explanation:
Meteoroids are the only ones of the four that are under a kilometer in size.
The most common experimental technique to perform elemental analysis is combustion analysis, where a sample is burned in a large excess of oxygen and the combustion products are trapped in a variety of ways. A 99.99% pure, 0.4808 g sample containing only carbon, hydrogen, and nitrogen is subjected to combustion analysis, resulting in the formation of 0.6859 g CO2, 0.6973 g H2O, and 0.4646 g NO. What is the empirical formula of the sample
Answer:
C₂H₅N₂
Explanation:
In the combustion analysis, all NO comes from the nitrogen of the sample, that means:
Moles NO = Moles N in the sample
In the same way:
Moles CO2 = Moles C in the sample
Moles H2O = 1/2 moles H in the sample
To solve this problem we must convert the mass of each gas to moles in order to find the moles of each atom. The empirical formula is the simplest whole number ratio of atoms presents in the molecule:
Moles NO = N -Molar mass: 30g/mol
0.4646g * (1mol / 30g) = 0.01549 moles N
Moles CO2 = C -Molar mass: 44.01g/mol-
0.6859g * (1mol / 44.01g) = 0.01559 moles C
Moles H2O = 1/2moles H -Molar mass: 18.02g/mol-
0.6973g * (1mol / 18.02g) = 0.03870 moles H
The ratio of atoms is -Dividing in the low number of moles = moles N-:
C = 0.01559 / 0.01549 = 1
N = 0.01549 / 0.01549 = 1
H = 0.03870 / 0.01549 = 2.5
Twice this ratio of atoms -Because empirical formula must be given only with whole numbers:
C = 2
N = 2
H = 5
The empirical formula is:
C₂H₅N₂What is NaC2H3O2 coefficient
Answer:yes coefficient u mean??
Explanation:
A wavelength is traveling at 6,420m/s and has a frequency of 600Hz. What is the wavelength
A 200 milliliter sample of gas has a pressure of 1 atmosphere. If the volume of the gas is decreased to 50 milliliters at constant temperature, the new pressure of the gas will be
1) 4 atm
2) 1 atm
3) 3 atm
4) 2 atm
Answer:
Answer is - 2. ...........
At constant temperature, if the volume of the sample of gas decreases, the pressure increases to 4.0atm.
Hence, option1)4 atm is the correct answer.
What is Boyle's law?Boyle's law simply states that "the volume of any given quantity of gas is inversely proportional to its pressure as long as temperature remains constant.
Boyle's law is expressed as;
P₁V₁ = P₂V₂
Where P₁ is Initial Pressure, V₁ is Initial volume, P₂ is Final Pressure and V₂ is Final volume.
Given the data in the question question;
Initial volume of the gas V₁ = 200mL = 0.2LInitial pressure of the gas P₁ = 1.0atmFinal volume of the gas V₂ = 50.mL = 0.05LFinal pressure of the gas P₂ = ?We substitute our given values into the expression above to determine the new pressure.
P₁V₁ = P₂V₂
P₂ = P₁V₁ / V₂
P₂ = ( 1.0atm × 0.2L ) / 0.05L
P₂ = 0.2Latm / 0.05L
P₂ = 4atm
At constant temperature, if the volume of the sample of gas decreases, the pressure increases to 4.0atm.
Hence, option1)4 atm is the correct answer.
Learn more about Boyle's law here: brainly.com/question/1437490
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Help (also tell me what the phenotype and genotypes are)
Answer:
genotype are the organism's hereditary information for example DNA
phenotype are the organism's physical characteristics for example your eyes or hair
or how your nose looks
what are the examples of Biosphere
patulong po thank you ❣️❣️
Answer:
[tex]\color{Blue}\huge\boxed{Answer} [/tex]
An example of the biosphere is where live occurs on, above and below the surface of Earth. The zone of planet earth where life naturally occurs, extending from the deep crust to the lower atmosphere. The living organisms and their environment composing the biosphere. The living organisms of the earth.
What is the Kc for the following reaction at equilibrium at 500∘C if [N2]= 0.41 M , [H2]= 0.41 M , and [NH3]= 2.2 M ? N2(g)+3H2(g)⇌2NH3(g)
Answer:
answer po Yan hope it help
Can you help with question 8
Answer:
pH = 9.4
Explanation:
With the given molarity of OH⁻ species we can calculate the pOH of the solution:
pOH = -log[OH⁻]
pOH = 2.6
Now we can use the pOH to calculate the pH of the solution, with the following formula:
pH = 14 - pOH
pH = 14 - 2.6
pH = 9.4
So a solution containing a OH⁻ concentration of 0.0025 M has a pH of 9.4.
25m
45m
Help pls.........
Answer:
45m
Explanation: