How many atoms are in 25.00 g of B?
A. 1.393 x 10^24 atoms of B
B. 1.333 x 10^23 atoms of B
C. 2.16 x 10^26 atoms of B
D.217 x 10^24 atoms of B
Thanks for all the efforts :)
Answers
Answer:
There are 1.393 x 10²⁴ atoms in 25.00 g of B.
Explanation:
Hey there!
We are given a value, in grams, that we need to convert to a number of atoms.
We can convert grams to atoms by using Avogadro's Number (\(N_A\)). This number is equivalent to \(6.022 \times 10^{23}\).
This number can be used to convert any values to:
atomsmoleculesformula unitsmolesIn order to do this problem, we will need to use dimensional analysis (DA). This process allows us to convert from grams to atoms.
We need to set up our ratios in order to work this out. We can use a periodic table to help us through this next part of the problem.
1. Locating the number of moles of B in the sample
We first need to find the amount of moles of boron (B) there are in the sample.
Checking a periodic table, the atomic mass in atomic mass units (amu) is 10.81 amu.
Atomic mass units can easily be converted to grams and these units can be used interchangeably.Therefore, for each atom of boron, it weighs 10.81 grams to us. This is equivalent to the mass of one mole of boron.
To find the number of moles, we have two possible ratios we can use:
\(\displaystyle \frac{1 \ mole \ B}{10.81 \ grams \ B}\)\(\displaystyle \frac{10.81 \ grams \ B}{1 \ mole \ B}\)These ratios mean the same thing, but we need to convert our final unit to moles.
We are given a sample in grams, and when dividing our units, we need to keep moles.
Since the first portion of our expression is in grams, we need to have grams in the bottom of our expression.
\(\displaystyle 25.00 \ \text{grams B} \ \times \frac{1 \text{mole B}}{10.81 \ \text{grams B}}\)We can now simplify the expression. Our grams B unit will cancel out, so we are therefore left with moles B remaining.
2. Locating the number of atoms in the sample
Now with our equation, we can convert our number of moles that would be solved if we stopped with the above. However, we need to convert to atoms.
We use Avogadro's number and create a ratio with that of moles.
\(\displaystyle \frac{6.022 \times 10^{23}\text{atoms}}{1 \text{mole B}}\)\(\displaystyle \frac{1 \text{mole B}}{6.022 \times 10^{23} \text{atoms}}\)We need to cancel out our moles and end with atoms, so we must have moles in the denominator. Therefore, we use the first ratio.
Using our previous expression, we multiply by this new ratio and solve the expression.
\(\displaystyle 25.00 \ \text{grams B} \ \times \frac{1 \text{mole B}}{10.81 \ \text{grams B}} \ \times \frac{6.022 \times 10^{23}\text{atoms}}{1 \text{mole B}}\)This expression can now be operated. You will need a calculator to perform this calculation.
Our numerator is:
\([(25.00 \times 1 \times (6.022 \times 10^{23})]\)Plugging this into a calculator, we get:
\(1.5055 \times 10^{25}\)Our denominator is:
\((1 \times 10.81 \times 1)\)This simplifies to:
\(10.81\)Dividing our numerator and denominator:
\(\displaystyle \frac{1.5055 \times 10^{25}}{10.81}\)Plugging this into a calculator, we get:
\(1.392691952 \times 10^{24}\)3. Simplifying with significant figures
Now, we need to take into account that we have significant figures. We are given this original value:
\(25.00\)This value has four significant figures, which means we need to round our value we received above to four significant figures.
\(\approx 1.393\)Our units are added as well as our scientific notation:
\(1.393 \times 10^{24} \ \text{atoms of B}\)Therefore, our final answer is choice A.
Related Questions
The molecular weight of water, H2O is 18.02 g/mol. How many moles of water are in 24.3 g of water?
Answers
Answer:
1.35moles
Explanation:
mm=18.02gmol⁻¹ mass=24.3g
mole=mass/mm
mole=24.3/18.02
mole=1.35moles
Answer:
The answer is 1.35 molesExplanation:
To find the number of moles given the molecular weight and mass we use the formula
\(n = \frac{M}{m} \\ \)
where
n is the number of moles
M is the molar mass
m is the mass of the substance
From the question
m = 24.3 g
M = 18.02 g/mol
We have
\(n = \frac{24.3}{18.02} \\ = 1.348501664...\)
We have the final answer as
1.35 molesHope this helps you
Which particles have approximately the same size and mass as each other?
A Neutrons and Electrons
B Protons and Neutrons
C Electrons and Protons
D None of these
Answers
Answer:
B.
Explanation:
Thus we can see that the mass of protons and mass of neutrons are approximately equal.
For which question could a scientist develop a testable hypothesis?
Which grocery store is the best?
When will dinosaurs roam Earth again?
Do all kinds of wood float in water?
Should everyone use solar-powered cars?
Answers
The question that a scientist can develop a testable hypothesis is as follows: Do all kinds of wood float in water? (option C).
What is a hypothesis?A hypothesis is a tentative conjecture explaining an observation, phenomenon or scientific problem that can be tested by further observation, investigation and/or experimentation.
The construction of hypothesis is a vital component of any experiment, which must be testable.
However, prior to the construction of hypothesis, a scientific question must be asked.
According to this question, the question that a scientist can develop a testable hypothesis is as follows: Do all kinds of wood float in water? The testable hypothesis will be to use different wood on water.
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90 is 50% of what number?
Part = Whole x Percent
P:
W:
%
Answers
Answer:
90 is 50% of 180
Explanation:
Just multiply 80 by 2 for 50%
1 point
When substances that make up baking powder are mixed with water,
carbon dioxide gas is formed. This is an example of *
a nuclear reaction
a physical reaction
a change of state
a chemical reaction
Answers
Which of the following is not a type of structural isomerism? A. Functional group B. Optical C. Chain D. Positional
Answers
Answer:
B. Optical
Explanation:
First, let's go through what isomerism is. Isomerism is the relation of two or more compounds, radicals, or ions that are composed of the same kinds and numbers of atoms but differ from each other in structural arrangement (structural isomerism), as CH3OCH3 and CH3CH2OH, or in the arrangement of their atoms in space and therefore in one or more properties. There are 5 types of structural isomerism. They are chain isomerism, position isomerism, functional group isomerism, metamerism, and tautomerism. This would mean that these types of structural isomerism that are in the options would be eliminated as the question ask which of the "following" is not a type of structural isomerism. This would leave the only option available which is Option B. Optical Isomerism. So instead of being a structural isomerism, it is a type of stereoisomerism. Stereoisomerism is the arrangement of atoms in molecules whose connectivity remains the same but their arrangement in space is different in each isomer.
Therefore, the answer is Option B. Optical.
in which part of the sun would the most helium be found?
Answers
it's most abundant in the mid latitudes.
Un tanque de acetileno para una antorcha de soldadura de oxiacetileno proporciona 9340 L de gas acetileno, C2H2, a 0°C y 1 atm 2CH2H2(g) + 502(g) -> 4CO2(g) + 2H2O(g) ¿Cuántos tanques de oxígeno, cada uno con 7x10³ L de o2 a 0°C y 1 atm, serán necesarios para quemar el acetileno?
Answers
Answer:
3.33 tanques de O₂
Explanation:
Basados en la reacción:
2C₂H₂(g) + 5O₂(g) → 4CO₂(g) + 2H₂O(g)
2 moles de acetileno reaccionan con 5 moles de oxígeno produciendo 4 moles de dióxido de carbono y 2 moles de agua
La ley de Avogadro dice que el volumen de un gas bajo temperatura y presión constantes es proporcional a las moles de este gas. Así, como 2 moles de acetileno reaccionan con 5 moles de oxígeno, los litros de O₂ necesarios para quemar 9340L de acetileno son:
9340 L C₂H₂ × (5 moles O₂ / 2 moles C₂H₂) = 23350L de O₂
Si un tanque contiene 7x10³ L de O₂ serán necesarios:
23350L O₂ ₓ (1 tanque / 7x10³L) = 3.33 tanques de O₂
What is the potential energy of a 5 kg apple that is sitting on a 1.5 m high
tree branch? GPE=ham
Answers
Answer:
PE = 73.58 J
Explanation:
Given data:
Mass of apple = 5 Kg
Height of tree = 1.5 m
Potential energy = ?
Solution:
Formula:
PE = mgh
g = 9.81 m/s
by putting values,
PE = 5 Kg × 9.81 m/s × 1.5 m
PE = 73.58 J (Kgm²/s = J)
What MASS of NaCl are required to make 2.69L of a 0.14M solution?Use the correct abbreviation for the UNITS
Answers
To solve this problem, let's use the definition for molarity:
Replacing the values of the problem:
Now, to find the mass, we multiply by the molecular weight of NaCl. (Which is about 58.44g/mol)
The answer is approximately 22.2g of NaCl
HELP ASAP
If a steel nail is wrapped 8 times with an insulated copper wire and each end of is attached to a 1.5 V single-A battery we find that it will lift the weight of 2 paper clips. Hypothesis: If 8 more coils are added to the nail we will be able to pick up twice as many paper clips. When we ran the experiment, we observed and recorded that when we added 8 more wraps around the nail (16 coils) we could lift 4 paper clips and when we added 8 more wraps (24 coils) we could lift 6 paper clips. Which of the following is/are true?
I. Something went wrong with the experiment since it didn't give us the results we expected.
II. The hypothesis was supported with the results of the experiment.
III. It can be concluded that every time 8 wraps are added to the nail, the total number of paper clips lifted doubles.
II and III only
II only
I only
I and III only
Answers
Based on the relationship between the number of turns of the coils and the strength of an electromagnet, the true options are:
The hypothesis was supported by the results of the experiment:
The correct option is II only.
What is the relationship between the number of turns of the coils and the strength of an electromagnet?The strength of the electromagnet rises with the number of turns in the coil.
This is due to the fact that as the coil "cuts" through the magnetic field, the sum of the individual emf s created by each turn increases with the number of coils turns.
The relative speed between the coil and magnet, as well as the magnet's strength, are additional elements that influence the strength of the induced current in a dynamo in addition to the number of coils. The intensity of the generated current increases with magnet strength and relative speed.
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- Would you expect the compound Ag3N to be a solid, liquid, or gas? Explain.
Answers
2C4 H10 + 13O2 -→ 8CO2 + 10H2O If 356 moles of O2 are available to react, how many moles of CO2 will fom?
Answers
Answer:
Answer:
The mole ratio of C₄H₁₀ and CO₂ is 2 : 8, which simplifies to 1 : 4.
Explanation:
The mole ratio is the relative proportion of the moles of products or reactants that participate in the reaction according to the chemical equation.
The chemical equation given is:
2C₄H₁₀ + 13O₂ → 8CO₂ + 10H₂O
Once you check that the equation is balanced, you can set the mole ratios for all the reactants and products. The coefficients used in front of each reactant and product, in the balanced chemical equation, tells the mole ratios.
In this case, they are: 2 mol C₄H₁₀ : 13 mol O₂ : 8 mol CO₂ : 10 mol H₂O
Since you are asked about the mole ratio of C₄H₁₀ and CO₂ it is:
2 mol C₄H₁₀ : 8 mol CO₂ , which dividing by 2, simplifies to
1 mol C₄H₁₀ : 4 mol CO₂, or
1 : 2.
Explanation:
What does the kinetic theory say about the kinetic energy present in solids
Answers
Answer: The kinetic energy of solids is limited to vibrational energies..the particles are tightly bound in their crystalline structure and can only bend, flex, and vibrate about relatively fixed position. When vibrational energies exceed the strength of the force holding the particles together, the crystal structure collapses and we say the material melted. The particles can now have, in addition to its vibrational energies, rotational energy. Chunks of the collapsed crystal can, like a ball floating in water, rotate without showing much translational energy. Generally, we associate solids with vibrational kinetic energy, liquids with rotational kinetic energy, and gases with translational kinetic energy. Actually though, liquids have both vibrational and rotational energies, and gases have all three.
(?)Fe+(?)H20 - - -> (?)Fe3O4+(?)H2
Answers
Answer:
what is this question??
Explain why the other types of decay are not considered fission
Answers
Answer:
As with cluster decay, alpha decay is not typically categorized as a process of fission. The first nuclear fission process discovered was fission induced by neutrons. Because cosmic rays produce some neutrons, it was difficult to distinguish between induced and spontaneous events.
12. Determine the number of moles of boric acid that react in the equation to produce 10 moles of water.
Answers
In the preceding equation, 6.67 moles of boric acid (\(H_3BO_3\)) will react to generate 10 moles of water (\(H_2O\)).
To determine the number of moles of boric acid that react in the equation to produce 10 moles of water, we need to examine the balanced chemical equation and use stoichiometry.
1. Begin by examining the balanced chemical equation for the reaction involving boric acid and water. Let's assume the equation is:
\(3H_2O\) + \(3H_2O\) -> \(B_2O_3\) + \(6H_2O\)
2. From the balanced equation, we can see that 2 moles of boric acid (H3BO3) react with 3 moles of water (\(H_2O\)) to produce 6 moles of water (\(H_2O\)).
3. Use the given information that 10 moles of water (\(H_2O\)) are produced. Since the stoichiometric ratio between boric acid and water is 2:3, we can set up a proportion to find the number of moles of boric acid:
2 moles \(H_3BO_3\) / 3 moles \(H_2O\) = x moles \(H_3BO_3\) / 10 moles \(H_2O\)
4. Cross-multiply and solve for x:
(2 moles \(H_3BO_3\))(10 moles \(H_2O\)) = (3 moles \(H_2O\))(x moles \(H_3BO_3\))
20 moles \(H_2O\) = 3x moles \(H_3BO_3\)
5. Divide both sides of the equation by 3 to isolate x:
x moles \(H_3BO_3\) = (20 moles \(H_2O\)) / 3
6. Calculate the value of x:
x moles \(H_3BO_3\) ≈ 6.67 moles \(H_3BO_3\)
Therefore, approximately 6.67 moles of boric acid (\(H_3BO_3\)) will react to produce 10 moles of water (\(H_2O\)) in the given equation.
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50 pts
In class, Ricardo rips up a piece of paper. Select the correct reason(s) that this is an example of a physical change. (more then one answer)
The paper no longer has smooth edges.
The paper has not produced a gas when torn.
The paper's chemical composition has been changed.
The paper has not changed colors.
The paper is still paper with the same chemical makeup.
Answers
Answer:
The paper no longer has smooth edges
The paper has not produced gas when torn
The paper has not changed colours
The paper is still paper with the same chemical makeup
2. The paper has not produced a gas when torn
3. The paper has not changed colors
4. The paper is still paper with the same chemical makeup
At what degree of sloping dose soil erosion begin to taper off
Answers
There is no specific threshold or degree of slope steepness at which soil erosion abruptly begins to taper off
Soil erosion is influenced by various factors, including slope steepness, rainfall intensity, soil characteristics, vegetation cover, and land management practices. As slope steepness increases, the potential for soil erosion generally increases due to the gravitational force acting on the eroded materials. However, there is no specific threshold or degree of slope steepness at which soil erosion abruptly begins to taper off. The relationship between slope steepness and soil erosion is generally non-linear. At low slope angles, soil erosion tends to be minimal as the gravitational force is relatively weak. As the slope angle increases, soil erosion typically increases exponentially due to the increased force of gravity. Eventually, as the slope steepness continues to increase, soil erosion may reach a point of maximum potential where the erodibility of the soil and other factors become limiting factors. Beyond this point, the rate of soil erosion may start to taper off, but it does not completely stop. Instead, it may stabilize or decrease slightly compared to the maximum erosion potential observed at steeper slopes.
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Which statement best describes energy?(1 point) Responses Energy is a push or pull on an object that will change the motion of the object. Energy is a push or pull on an object that will change the motion of the object. Energy is the ability to do work. Energy is the ability to do work. Energy is the force that causes movement in an object. Energy is the force that causes movement in an object. Energy is the power derived from the utilization of simple machines. Energy is the power derived from the utilization of simple machines.
Answers
The statement that best describes energy is energy is the ability to do work. Option 3 is correct.
Energy is a property or characteristic of a system or object that allows it to perform work. Work, in physics, is defined as the force applied to an object multiplied by the distance over which the force is applied. Energy can be transformed from one form to another, but it cannot be created or destroyed. It can only be transferred from one object or system to another.
Energy can be stored in different forms such as potential, kinetic, thermal, chemical, electrical, and nuclear energy. Potential energy is the energy that an object possesses due to its position or state, whereas kinetic energy is the energy of motion. Thermal energy is the energy of a system or object due to its temperature, and chemical energy is the energy stored in the bonds between atoms and molecules. Option 3 is correct.
The complete question is
Which statement best describes energy?
Responses Energy is a push or pull on an object that will change the motion of the object. Energy is a push or pull on an object that will change the motion of the object. Energy is the ability to do work. Energy is the force that causes movement in an object. Energy is the force that causes movement in an object. Energy is the power derived from the utilization of simple machines. Energy is the power derived from the utilization of simple machines.To know more about the Energy, here
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PLS HELP GAS LAW PROBLEM
Answers
V1/T1=V2/T2
when assigning variables:
T1= 285K
V1= .315L
T2=311K
V2= ?
to find V2, plug in the variables into the equation
.315/285=311/V2
cross multiply V1 and T2: .315(311)=97.965
then divide by 285
97.965/285= .343L
so your answer is .343L :)
A car travels 60 m/s for 60 seconds. Calculate how farit traveled.
Answers
Answer:3600 meters
Explanation:
If a car travels 60 meters a second for 60 seconds that means it traveled 60*60 meters which is 3600
Identify the body's fuel source as its metabolic pathways shift from feasting to fasting. Glycogen stores Body fat stores Body protein Fuel for the body 2 to 3 hours after eating Fuel for the body after 24 hours of starvation Fuel for the brain 2 to 3 hours after eating Fuel for the brain after 24 hours of starvation O
Answers
The body's fuel source as its metabolic pathways shift from feasting to fasting. Glycogen stores Body fat stores b. Fuel for the body after 24 hours of starvation
Glycogen stores, primarily in the liver and muscles, are the primary fuel source for both the body and the brain. Glycogen is a stored form of glucose that is quickly mobilized for energy when needed. After 24 hours of starvation, glycogen stores are depleted, and the body turns to its fat stores for energy. Fatty acids are released and converted to ketone bodies, which can be used as fuel by most tissues, including the brain.
However, ketone bodies cannot fully meet the brain's energy demands, so the body also breaks down its own proteins to produce glucose, primarily from skeletal muscle. In summary, during the first few hours after eating, glycogen stores provide b. fuel for the body and brain. After 24 hours of starvation, body fat stores become the primary energy source, while the brain relies on both ketone bodies and glucose derived from the breakdown of body proteins.
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you have 0.5 liters of a gold chloride solution you add 0.5 liters to the solution creating one liter of solution with a concentration of 0.26 M. what was the original concentration.
Answers
The original concentration of the gold chloride solution was 0.52 M.
To determine the original concentration of the gold chloride solution, we can use the concept of dilution. When two solutions of different concentrations are mixed together, the resulting concentration can be calculated using the formula:
C1V1 = C2V2
where C1 and V1 represent the initial concentration and volume, and C2 and V2 represent the final concentration and volume.
Given that the final volume is 1 liter and the final concentration is 0.26 M, and the volumes of the original and added solutions are both 0.5 liters, we can substitute these values into the formula:
C1 * 0.5 L = 0.26 M * 1 L
Simplifying the equation:
C1 = (0.26 M * 1 L) / 0.5 L
C1 = 0.52 M
The calculation is based on the assumption that the dilution process is an ideal dilution, where there is no change in the total amount of gold chloride present in the solution during the mixing process. Additionally, it assumes that there are no chemical reactions or interactions between the two solutions.
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calculate amount of tin and mass percentage
Answers
Amount of tin in the sample is 2.2837 gm and its mass percentage in the rock is 22.837%
I₃⁻ (aq) + Sn⁺² (aq) → Sn⁺⁴ (aq) + 3I⁻
1 mol 1 mol
mol of NaI₃ = 34.60 mL × 1 L / 1000 mL × 0.5560 mol / L
= 19.2376 × 10⁻³ mol
∵ 1 mol of Sn²⁺ = 1 mol of I₃⁻
∴ mol of Sn²⁺ = 19.2376 × 10⁻³
∴ mass of Sn in sample = mol of Sn²⁺ × molar mass
= ( 19.2376 × 10⁻³ mol ) × 118.71 gm/mol
= 2.28369 gm
= 2.2837 gm
∴ % of tin in sample = (mass of tin) / (mass of sample ) × 100
The mass percent of a solution is defined as the ratio of the mass of solute that is present in a solution, relative to the mass of the solution
= 2.2837/10 × 100
= 22.837 %
Thus we can conclude that amount of tin in the sample is 2.2837 gm and its mass percentage in the rock is 22.837%
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what type of reaction is
CH 4 (g)+2O 2 (g) CO 2 (g)+2H 2 O(g)
Answers
Answer: combustion
Explanation:
Combustion reactions can be identified by looking at the reactants and the products.
Usually, the reactants will be a hydrocarbon and oxygen. And the products will be CO2 and H2O
Which of the following is an example of a device that transfers one type of energy into another?
Answers
Answer:
Energy transfer is the movement of energy from one location to another. For example, when electricity moves from a wall plug, through a charger, to a battery.
Explanation:
Hope this helps
identify the limiting reactant when 7.28 grams of magnesium oxide reacts with 4.50 grams of aluminum to make magnesium and aluminum oxide? i need a typed answer a link wont work
Answers
Answer:
the limiting reactant is aluminum
Explanation:
60 POINTS! PLEASE ANSWER!
Answers
What volume is occupied by 0.580 mol of gas at 98.4 kPa and 11°C?
please help with steps
Answers
The ideal gas law equation can be used to solve this sum. Thus, a 0.580 mol of gas at 98.4 kPa and 11°C occupies a volume of 12.6 L.
What is the ideal gas law?The ideal gas law is a rudimentary equation in physics and chemistry that reports the behaviour of ideal gases under different states. The law is expressed mathematically as:
PV = nRT
R is the universal gas constant.
First, we need to convert the given temperature of 11°C to Kelvin:
T = 11°C + 273.15 = 284.15 K
Next, we can plug in the given values and solve for V:
V = nRT/P
V = (0.580 mol)(8.31 J/(mol K))(284.15 K)/(98.4 kPa)
V = 12.6 L
Therefore, 0.580 mol of gas at 98.4 kPa and 11°C occupies a volume of 12.6 L.
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