How many moles of iron in a sample that contains 7.91×10^23 atoms of iron?
Answer: 1.31
Explanation:
No.of moles = given no.of atoms/Avagadro number
= 7.91×10^23 / 6.022 x 10^23
= 1.31
therefore, no.of moles = 1.31
Hope it helped u,
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what volume of carbon 4 oxide measured at STP will produce when 21 gram of sodium hydrogen carbonate for is completely decomposed accor. ding to the equation. (Na=23. H=1 C=12 O=16) molar vol =22.4dmcube. pleeeeeeeeeeese help
The volume of CO₂ at STP = 2.8 L
Further explanationGiven
21 gram of sodium hydrogen carbonate-NaHCO₃
Required
Volume of CO₂
Solution
The decomposition of sodium bicarbonate into sodium carbonate, carbon dioxide, and water :
2 NaHCO₃(s) → Na₂CO₃(s) + CO₂(g) + H₂O(g)
mol of NaHCO₃ :
= mass : MW NaHCO₃
= 21 g : 84 g/mol
= 0.25
From the equation, mol ratio of NaHCO₃(s) :CO₂(g) = 2 : 1, so mol CO₂ :
= 1/2 x mol NaHCO₃
= 1/2 x 0.25
= 0.125
At STP, 1 mol gas = 22.4 L, so for 0.125 mol :
= 0.125 x 22.4 L
= 2.8 L
Plutonium is part of what series of elements?
Answer:
Plutonium is the second transuranium element of the actinide series.
The main fuel for a fast neutron reactor is plutonium, which is gradually created in any reactor from non-fissile U-238, which makes up more than 99% of natural uranium. The actinide series' second transuranium element is plutonium.
Pu is the atomic symbol for plutonium, which bears the numbers 94 and 244 in its atomic weight. On a periodic chart, plutonium is located in period 7, which is part of the actinides group.
With an atomic number of 94, plutonium is the second transuranic element and a member of the actinide group on the periodic table. Like its precursor, neptunium, which was named after the planet Neptune, Plutonium is named after the planet Pluto.
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True or false: the smaller the difference between the average experimental value and the correct (true) value the greater the accuracy
Answer:
True
Explanation:
The accuracy level is usually determined by the difference between the experimental and correct value. It is important to note that the smaller the difference between the average experimental value and the correct (true) value, the more accurate it is.
When the difference is large then it means the accuracy level is low and not up to the required standard.
Even before modern observations provided evidence supporting the theory of plate tectonics, people developed theories that the continents were once joined together. Using only maps, what did they observe?
Answer:
people or scientist tend to observe the nature of the continents that described by jigsaw fit,geological similarity among the continents
How many atoms of oxygen are in 0.400 moles of N205?
Answer:
0.400 mol N2O5 contains 2.41 molecules N2O5 .
Explanation:
If a container holds 5.00 moles of gas and the total pressure is 5.00 atm., what is the partial pressure for each mole of gas?
Answer:
1 atm
Explanation:
From the question given above, the following data were obtained:
Total mole = 5 moles
Total pressure = 5 atm
Partial pressure for each mole =.?
Next, we shall determine the mole fraction for each mole of the gas. This is illustrated below:
Since the container holds 5 moles of gas, then the mole fraction for each mole of the gas will be 1/5.
Finally, we shall determine the partial pressure for each mole of the gas as follow:
Mole fraction for each mole = 1/5
Total pressure = 5 atm
Partial pressure for each mole =.?
Partial pressure = mole fraction × total pressure
Partial pressure = 1/5 × 5
Partial pressure = 1 atm
Thus, the partial pressure for each mole of the gas is 1 atm.
With pollution on the rise, and demand for fresh water increasing, world leaders are concerned that in the future many people will not have access to clean drinking water. Select the statement that best describes the long-term global effects of this behavior.
People do not need to be concerned because there is an unlimited supply of fresh water on the Earth so we will never run out.
Fresh water is a limited resource. If we pollute the fresh water we have, there will be a shortage of clean drinking water in the future.
The Earth is getting warmer and if all the ice melts the sea level will rise and we will have more fresh water.
There will always be enough fresh water because the Earth is about 75% water and it surrounds every continent.
Fresh water is a limited resource. If we pollute the fresh water we have, there will be a shortage of clean drinking water in the future.
Plz answer it I’ll give people points (math)
Sample A is measured to have a mass of 7.3g and sample B has a mass of 8.28g. Which measurement best describes their combined mass?
A.16g
B.15.58g
c.15.5g
D15.6g
The specific heat of aluminum is s 9.00 J/g C how much energy is needed to raise the temperature of 20.0 g block of aluminum from 22.8 C to 94.6 C
Click this link to view O*NET's Work Context section for Emergency Medical Technicians. Note that common tools
are listed toward the middle. According to O*NET, what are some common work tools for Emergency Medical
Technicians? Select four options.
ladders, scaffolds, or poles
Airway suction units
Intravenous IV pressure infusers;
Head and body pumps
Cardboard splints
Full-spine immobilization devices
Answer:
( B, C, E, F)
Explanation:
Person above is right!
But I hope this helps!!
Intravenous IV pressure infusers, Airway suction units, full spine immobilization devices, and cardboard splints are required for Emergency Medical Technicians.
What are medical technicians?A medical worker known as a medical technician supports doctors and hospitals and hence plays a crucial role in the healthcare sector. They have various important roles during medical emergencies.
They are in charge of duties like checking blood in labs or physiological fluids like perspiration or tissue samples so doctors can decide on treatment options in a well-informed manner.
Intravenous IV pressure infusers, Airway suction units, full spine immobilization devices, and cardboard splints units are required for Emergency Medical Technicians. Hence, options B, C, E, and F are correct.
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what volume of carbon 4 oxide measured at STP will produce when 21 gram of sodium hydrogen carbonate for is completely decomposed accor. ding to the equation. (Na=23. H=1 C=12 O=16) molar vol =22.4dmcube. pleeeeeeeeeeese help,
The volume of CO₂ at STP = 2.8 L
Further explanationGiven
21 gram of sodium hydrogen carbonate-NaHCO₃
Required
Volume of CO₂
Solution
The decomposition of sodium bicarbonate into sodium carbonate, carbon dioxide, and water :
2 NaHCO₃(s) → Na₂CO₃(s) + CO₂(g) + H₂O(g)
mol of NaHCO₃ :
= mass : MW NaHCO₃
= 21 g : 84 g/mol
= 0.25
From the equation, mol ratio of NaHCO₃(s) :CO₂(g) = 2 : 1, so mol CO₂ :
= 1/2 x mol NaHCO₃
= 1/2 x 0.25
= 0.125
At STP, 1 mol gas = 22.4 L, so for 0.125 mol :
= 0.125 x 22.4 L
= 2.8 L
fill in the blank the proportion
5:7=_____:49
18:_____=6:4
[tex]3a - (b.a) - (c - d) + 4d + 5c - 8a = [/tex]
Answer:
(1) 3
(2) 12
(3) -ab+4c+5d-5a
Which of the following is a characteristic of farsighted eyes?
cannot see clearly at any distance
can see things up close most clearly
cannot see things clearly at a distance
can see things most clearly at a distance
Answer:
can see things most clearly at a distance
Answer:
cannot see clearly at a distance farsighted.
can see things up close most clearly not farsighted.
cannot see things clearly at a distance farsighted a little bit.
can see things most clearly at a distance not even farsighted or close sighted.
Explanation:
What explanation you need.
A circuit is:
A. the path for the movement of charge.
B. always an open loop.
C. an excess accumulation of charge.
D. the movement of electric charge.
Answer:
A. the path for the movement of charge.
Explanation:
A circuit is the path for the movement of charge.
What does the host mean when he says that the acid has "donated a proton" to the water?
A.
When hydrochloric acid is dissolved in water, a proton disappears in the chemical reaction.
B.
When hydrochloric acid dissociates, a positive hydrogen atom is accepted by water to form H₃O+.
C.
When hydrochloric acid dissociates, a negative hydrogen atom is accepted by water to form H₃O-.
Answer:
Option B
Explanation:
As Brønsted-Lowry theory states, acids are the ones that can donate protons.
When a proton is donated, it is released to become medium more acidic.
HCl is a strong acid.
HCl (l) + H₂O (l) → H₃O⁺ (aq) + Cl⁻(aq)
These always reffers to strong acid where the dissociation is 100% completed.
In a weak acid, dissociation is not 100% complete, that's why we have an equilibrium.
HA (l) + H₂O (l) ⇄ H₃O⁺ (aq) + A⁻(aq) Ka
10. As the temperature of a fixed volume of a gas increases, the pressure will _______
answer is increase
the equation of bromination of methane
ASAP will get Brainiest
question in pic ( multiple select )
Answer:
Balanced, Unbalanced, Unbalanced, Balanced, Unbalanced.
Explanation:
A student sitting at a desk has no kinetic energy, he/she/they are not moving or exerting force. A rocket taking off is in the process of releasing energy, pushing the rocket upward, attempting to balance the forces of gravity and downward force. A building collapsing has kinetic energy, as gravity has now become greater than that of the force pushing against it. A satellite has balanced force because nothing is acting upon it other than gravity, at which distance, by the fact that is orbiting, is not moving towards or away from the item which has put force on it. When you are in a car at a constant speed, you may move in it as if it is stationary, because the friction on the wheels and wind speed create balanced forces against the engine. From outside of the car, these forces are unbalanced, as the car is propelled, which is what I believe the question is asking.
Hope this helps!
How do chemists organize information about elements?
O A. By grouping the elements on the periodic table
B. Through application of the atomic theory
O C. Through use of the scientific method
D. Through development of quantum mechanics
Mass = ?
Acceleration = 10 m/s2
Force = 20 N
I NEED HELP ASAP!!!
1.5g of magnesium ribbon is burnt in oxygen to produce 2.5g of magnesium oxide. How much oxygen is required in grams?
Answer:
2.5 grams
Explanation:
law of conservation of mass applies. the magnesium completely burns
Which sample contains a total of 6.0 x 1023 particles?
Answer: 6,138
:)
Explanation:
A car travels 60 m/s for 60 seconds. Calculate how farit traveled.
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
Why the molecular formula of calcium carbide is cac2 but not ca2c
Answer:
The two carbons have a triple bond leaving two unpaired electrons which take the two calcium electrons to form the acetylide ion (C2–2) and the Ca+2 ion. The C-4 ion is not a stable species.
One type of butterfly has either green and pink wings or solid green wings. One year many more solid green butterflies survived than the
green and pink ones.
Why did more of the green butterflies survive?
O A They were able to build nests higher in the forest canopy.
OB. They were able to eat different types of foods other than just plants.
O c They were able to fly faster because they had different types of wings.
OD. They were able to blend in better with the plants and hide from predators.
Answer:
C
Explanation:
C is the only answer that is affected by the color of the wings.
Which Earth motion describes the wobbling of the Earth around its precessional axis and
could alter the amount of seasonal effects? *
Precession
Nutation
Barycenter
Revolution
Answer:
Nutation
Explanation:
The counterclockwise rotation of planet earth around its own axis is defined as the Earth Rotation. The earth rotates about the line called "the axis of rotation," it is an imaginary line that passes through the North and South Poles of the planet, which the earth rotates about.
Hence, earth rotates once in about 24 hours with respect to the Sun, from West to East and thus giving rise to;
a. Day and night
b. Seasons
The Earth motion which describes the wobbling of the Earth around its precessional axis and could alter the amount of seasonal effects is known as nutation.
Basically, nutation usually occurs when the precessional motion of a planetary body such as planet earth experience some form of irregularities when it is rotating.
Help me with this pls
Answer:
the first three are the correct answer
Calculate the weight of the rocks in the photo. The measurement from the scale is given in the caption. (textbook page 8 picture next to question 7) This is what it says on caption: m=0.5 kg Formula: F= m x a force (F), mass (m), acceleration (a) Formula: F= _____kg x 9.8 m/s^2 Answer: F= _____ kg x m/s^2 Type your answer answer:
Answer:
The correct answer is - 4.9 kg x m/s^2.
Explanation:
The weight of any object is the mass of the object in specific gravity applied to the object. It can be represented by the F=ma where F is the force applied on the earth by the gravity (a) and mass of the object (m).
Solution:
F = ma
F = 0.5*9.8 kg x m/s^2.
= 4.9 kg x m/s^2.
