The number of atoms in an elemental atom can be estimated by Avogadro's number or the number of equivalents. In 50 grams of calcium, there are 7.53 × 10²³ atoms.
What is Avogadro's number?Avogadro's numbers are used to estimate the number of smaller entities like the number of atoms and molecules in a compound for a substance. It determines the atom in a given mass of the atom. Avogadro's number (Nₐ) is equal to 6.022 × 10²³.
Given,
Mass of calcium = 50 gm
The molar mass of calcium = 40 gm/mol
The moles are calculated from mass and molar mass as:
Moles = mass ÷ molar mass
n = 50 ÷ 40
= 1.25 mol
It is known that a mole of a substance contains Nₐ atoms.
1 mol = 6.022 × 10²³ atoms
Then, 1.25 mol = 1.25 × 6.022 × 10²³
= 7.53 × 10²³
Therefore, there are 7.53 × 10²³ atoms in 50 grams of calcium.
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How much NaOH (in grams) is needed to prepare 463 mL of solution with a pH of 10.020?
Answer: [tex]1.94\times 10^{-3}g[/tex] of NaOH
Explanation:
pH or pOH is the measure of acidity or alkalinity of a solution.
pH is calculated by taking negative logarithm of hydrogen ion concentration.
[tex]pH=-\log [H^+][/tex]
Putting in the values:
[tex]10.020=-\log[H^+][/tex]
[tex][H^+]=9.55\times 10^{-11}[/tex]
[tex][H^+][OH^-]=10^{-14}[/tex]
[tex][OH^-]=\frac{10^{-14}}{9.55\times 10^{-11}}=1.05\times 10^{-4}M[/tex]
[tex]NaOH\rightarrow Na^++OH^-[/tex]
[tex]Molarity=\frac{moles\times 1000}{\text {Volume in ml}}[/tex]
[tex]1.05\times 10^{-4}M=\frac{moles\times 1000}{463ml}[/tex]
moles = [tex]4.86\times 10^{-5}[/tex]
Mass of [tex]NaOH=moles\times {\text {Molar mass}}=4.86\times 10^{-5}\times 40=1.94\times 10^{-3}g[/tex]
Thus [tex]1.94\times 10^{-3}g[/tex] of NaOH is needed to prepare 463 mL of solution with a pH of 10.020
Proper lane placement can include positioning your car...
A. away from other cars.
B. 36 inches from the right or left line.
C. one inch from either lane line.
Proper lane placement can include positioning your car 36 inches from the right or left line. Therefore, option B is correct.
What is lane positioning ?Using different lane positions to make adjustments for potential problems and create larger space between car and problem situations. Lane position is the placement of car in the center, on the right, or on the left of a lane. The width of a lane is twelve feet on most highways or streets.
There are three main positions are lane position 1 is center of lane, lane position 2 is left side, and lane position 3 is right side. Position 2 is left side of lane is for car.
Position 3 is a vehicle placement to the right when a restriction to path of travel or your line of sight occurs. Proper lane placement can include positioning your car 36 inches from the right or left line.
Thus, option B is correct.
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What is the correct answer? Please
Answer:
c
Explanation:
After brushing, Fluffy's fur has a charge of +8.0 x 10' coulombs and her plastic brush has a charge of -1.4 x 10-8 coulombs. If the distance between the fur and
brush is roughly 5.0 * 10 meters, what is the approximate magnitude of the force between them?
(k = 9.0 * 10 newtonmeters/coulomb?)
A 5.0 x 106 newtons
B.
2.0 x 10-4 newtons
C
4.0 x 106 newtons
D. 2.5 x 10 newtons
Reset
Next
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SUS
Answer:
jeez thats some calculus stuff right there im pretty sure its b
Explanation:
NEED HELPPP PLSSSSSSSSSS
chemistry neutralization
Answer:
In chemistry, neutralization or neutralisation is a chemical reaction in which acid and a base react quantitatively with each other. In a reaction in water, neutralization results in there being no excess of hydrogen or hydroxide ions present in the solution.
Explanation:
Which situation describes why a rock sinks in water?
A. Air pressure is greater than the buoyant force.
B. The force of gravity is greater than the buoyant force.
c. The buoyant force is greater than the force of gravity.
D. The rock is less dense than water.
Answer:
b
Explanation:
Relate dark matter to the development of the universe after the Big Bang. In 3-5 sentences, speculate on how the development of the universe would have been different if there had been no dark matter. In your answer, use the term structures.
Please answer this and ill mark you as brainliest
Answer:
Dark matter also called baronic matter is the matter that makes up 27% of the universe.
In 1933 it was determined as that mass that cannot be seen, that is, the non-visible mass of outer space.
Dark matter also plays a central role in the formation of structures and the evolution of galaxies and has measurable effects on the anisotropy of cosmic microwave background radiation. The composition of this matter is unknown today.
The dark matter component has considerably more mass than the "visible" component of the Universe.
Explanation:
There are certain researchers who say that the appearance of dark matter was before the appearance of the big bang.
A relevant fact of this matter is that dark matter exerts gravity, and that gravity affects the movements of objects.
Despite the fact that nothing is known about its origin, astronomers have amply demonstrated that dark matter plays a determining role in the formation of galaxies and galactic clusters, which could not maintain their cohesion without its existence, but many doubt that it is the remainder / remnant or product of a big bang.
What does “moving slow” mean to a geologist?
A landslide can be defined as a mass movement of material (e.g., rocks), which moves down a steep slope. A geologist is an expert that studies SLOW-MOVING landslides on a geological scale.
Landslides can occur suddenly or more slowly over long periods of time.
On a geological scale, landslides occur slowly so they are imperceptible to humans.
A geologist is a professional who investigates landslides on a geological scale, which is coarse on a human time-frame.
In conclusion, a geologist is a professional who investigates SLOW-MOVING landslides on a geological scale.
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The specific heat capacity of lead is 0.130 J/g-K. How much heat
is required to raise the temperature of 15.0 g of lead from 22.0 °C
to 37.0 °C?
Answer:
Q= 29.2 J
Explanation:
22°C=295K
37°C=310K
Q= mC dT
Q= (15.0 g) *(0.130 J/g-K)* (310 K-295K)
Q= 29.2 J
29.2 J is required to raise the temperature of 15.0 g of lead from 22.0 °C to 37.0 °C.
What is specific heat capacity?The specific heat capacity is defined as the quantity of heat (J) absorbed per unit mass (kg) of the material when its temperature increases by 1 K (or 1 °C), and its units are J/(kg K) or J/(kg °C).
Given data:
22°C=295K
37°C=310K
Applying specific heat capacity formula:
Q= mC dT
Putting all the values in the formula:
Q= (15.0 g) X (0.130 J/g-K) X (310 K-295K)
Q= 29.2 J
Hence, 29.2 J is required to raise the temperature of 15.0 g of lead from 22.0 °C to 37.0 °C.
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Which of the following are characteristics of heterogeneous mixtures
A. distinguishable components
B. evenly distributed components
C. particles too small to be seen with a microscope
D. components in varying proportions
E. particles that may settle
Answer:
c
Explanation:
How many electrons with chlorine (Cl) in group 17 gain to become stable?
Answer:
Sodium is in group 1 so it has 1 valence electron (one electron in its outer shell). Sodium will be looking to lose its one valence electron in order to become more stable. Chlorine is in group 17 so it has 7 valence electrons, and therefore only needs to gain one valence electron to attain noble gas electron configuration (become stable with 8 valence electrons, just like the noble gases in group 18 have 8). Because the chlorine atom is trying to gain one electron, and the sodium atom is trying to lose one, sodium will give up its one valence electron to chlorine and the two atoms will form an ionic bond. Because chlorine is looking to gain just one electron and sodium is looking to lose the same number, the ratio of chlorine atoms to sodium atoms will be 1:1, one chlorine atom per one sodium atom.
Explanation:
Which of the following is the energy of moving electrons?
a. kinetic energy
b. thermal energy
c. nuclear energy
d. electrical energy
Answer:
Electrical energy
Explanation:
Electrical energy is caused by the moving of electrons.
hope it helps!
If 50.0 g of KCl reacts with 50.0 g of O2 to produce KClO3 according to the following equation, how many grams of KClO3 will be formed? Word and Formula equation.
Answer:
A. 82.2g of KClO3
B. Word equation:
50g of KCl react with 50g of O2 to produce 82.2g of KClO3
C. Formula equation:
2KCl + 3O2 —> 2KClO3
Explanation:
The balanced equation for the reaction. This is given below:
2KCl + 3O2 —> 2KClO3
Next, we shall determine the masses of KCl and O2 that reacted and the mass of KClO3 produced from the balanced equation. This is illustrated below:
Molar Mass of KCl = 39 + 35.5 = 74.5g/mol
Mass of KCl from the balanced equation = 2 x 74.5 = 149g
Molar Mass of O2 = 16x2 = 32g/mol
Mass of O2 from the balanced equation = 3 x 32 = 96g
Molar Mass of KClO3 = 39 + 35.5 + (16x3) = 122.5g/mol
Mass of KClO3 from the balanced equation = 2 x 122.5 = 245g
Summary:
From the balanced equation above:
149g of KCl reacted.
96g of O2 reacted.
245g of KCl were produced.
Next, we shall determine the limiting reactant. This is illustrated below:
From the balanced equation above,
149g of KCl reacted with 96g of O2.
Therefore, 50g of KCl will react with = (50 x 96)/149 = 32.21g of O2.
Since a lesser mass of O2 ( i.e 32.21g) than what was given (i.e 50g) is needed to react completely with 50g of KCl, therefore, KCl is the limiting reactant and O2 is the excess reactant.
A. Determination of the mass of KClO3 produced from the reaction.
In this case the limiting reactant will be used.
From the balanced equation above,
149g of KCl reacted To produce 245g of KClO3.
Therefore, 50g of KCl will react to produce = (50 x 245)/149 = 82.2g of KClO3.
Therefore, 82.2g of KClO3 is produced from the reaction.
B. Word equation:
50g of KCl react with 50g of O2 to produce 82.2g of KClO3.
C. Formula equation:
2KCl + 3O2 —> 2KClO3
The mass of [tex]\rm KClO_3[/tex] produced has been 82.1085 g.
The word equation for the reaction has been: 50 gram potassium chloride reacts with 50 g oxygen to give 82.1085 g potassium chlorate.
The formula equation has been, [tex]\rm 2\;KCl\;+\;3\;O_2\;\rightarrow\;2\;KClO_3[/tex].
The balanced chemical equation for the reaction has been given as:
[tex]\rm 2\;KCl\;+\;3\;O_2\;\rightarrow\;2\;KClO_3[/tex]
Computation for Mass of Potassium chlorate:From the balanced chemical equation, 2 moles of KCl reacts with 3 moles of oxygen to give 2 moles of [tex]\rm KClO_3[/tex].
The moles of reactants have been given as:
[tex]\rm Moles=\dfrac{mass}{molar\;mass}[/tex]
The moles of 50 g KCl has been given as:
[tex]\rm Moles\;KCl=\dfrac{50}{74.55} \\Moles\;KCl=0.67\;mol[/tex]
The moles of KCl available has been 0.67 mol.
The moles of 50 g [tex]\rm O_2[/tex] has been given as:
[tex]\rm Moles\;O_2=\dfrac{50}{32}\\Moles\;O_2=1.5625\;mol[/tex]
The moles of 50 g [tex]\rm O_2[/tex] has been 1.5625 mol.
From the balanced equation, for 2 moles KCl, 3 moles oxygen has been required. For 0.67 mol KCl, oxygen required has been:
[tex]\rm 2\;mole\;KCl=3\;moles\;O_2\\0.67\;mol\;KCl=\dfrac{3}{2}\;\times\;0.67\;mol\;O_2\\0.67\;mol\;KCl=1.005\;mol\;O_2[/tex]
The available moles of oxygen has been 1.5625 mol. Thus, oxygen has been excess reactant and KCl has been limiting reactant.
The moles of [tex]\rm KClO_3[/tex] produced has been given as:
[tex]\rm 2\;mol\;KCl=2\;mol\;KClO_3\\0.67\;mol\;KCl=\dfrac{2}{2}\;\times\;0.67\;mol\;KClO_3\\0.67\;mol\;KCl=0.67\;mol\;KClO_3[/tex]
The moles of [tex]\rm KClO_3[/tex] produced has been 0.67 mol.
The mass of [tex]\rm KClO_3[/tex] produced has been:
[tex]\rm Mass=Moles\;\times\;molar\;mass\\Mass\;KCl=0.67\;\times\;122.55\;\\Mass\;of\;KCl=82.1085\;g[/tex]
The mass of [tex]\rm KClO_3[/tex] produced has been 82.1085 g.
The word equation for the reaction has been:
50 gram potassium chloride reacts with 50 g oxygen to give 82.1085 g potassium chlorate.
The formula equation has been, [tex]\rm 2\;KCl\;+\;3\;O_2\;\rightarrow\;2\;KClO_3[/tex].
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Accoring to KMT gases are_____
mostly empty space
or
very dense
or
organized
Answer:
Explanation:
mostly empty space
33 types of clouds and locations
Answer:
Cirrus
Cirrus cloudsCirrus clouds are delicate, feathery clouds that are made mostly of ice crystals. Their wispy shape comes from wind currents which twist and spread the ice crystals into strands.
Cirrostratus
Cirrostratus cloudsCirrostratus clouds are thin, white clouds that cover the whole sky like a veil. These clouds are most commonly seen in the winter, and can cause the appearance of a halo around the sun or the moon.
Cirrocumulus
Cirrocumulus cloudsCirrocumulus clouds are thin, sometimes patchy, sheet-like clouds. They sometimes look like they’re full of ripples or are made of small grains.
Mid-level Clouds (6,500-23,000 feet)
Altocumulus
Altocumulus cloudsAltocumulus clouds have several patchy white or gray layers, and seem to be made up of many small rows of fluffy ripples. They are lower than cirrus clouds, but still quite high. They are made of liquid water, but they don’t often produce rain.
Altostratus
Altostratus cloudsAltostratus clouds are gray or blue-gray mid-level clouds composed of ice crystals and water droplets. The clouds usually cover the entire sky.
Nimbostratus
Nimbostratus cloudsNimbostratus clouds are dark, gray clouds that seem to fade into falling rain or snow. They are so thick that they often blot out the sunlight.
Low Clouds (less than 6,500 feet)
Cumulus
Cumulus cloudsCumulus clouds look like fluffy, white cotton balls in the sky. They are beautiful in sunsets, and their varying sizes and shapes can make them fun to observe!
Stratus
Stratus cloudsStratus cloud often look like thin, white sheets covering the whole sky. Since they are so thin, they seldom produce much rain or snow. Sometimes, in the mountains or hills, these clouds appear to be fog.
Cumulonimbus
Cumulonimbus cloudCumulonimbus clouds grow on hot days when warm, wet air rises very high into the sky. From far away, they look like huge mountains or towers.
Stratocumulus
Stratocumulus cloudStratocumulus clouds are patchy gray or white clouds that often have a dark honeycomb-like appearance.
Special Clouds
Contrails
(Photo of white streaks of contrails in the sky) Contrails are made by high-flying jet airplanes. They are still clouds, though, because they are made of water droplets condensed from the water vapor in the exhaust of the jet engines.
Weather prediction: Contrails can provide information about the layers of moisture in the sky.
Mammatus clouds
Mammatus cloudsMammatus clouds are actually altocumulus, cirrus, cumulonimbus, or other types of clouds that have these pouch-like shapes hanging out of the bottom. The pouches are created when cold air within the cloud sinks down toward the Earth.
Orographic clouds
Orographic cloudsOrographic clouds get their shape from mountains or hills that force the air to move over or around them. They can also be formed by sea breezes and often appear as lines where two air masses meet.
Lenticular clouds
Lenticular clouds are shaped like lenses or almonds or...flying saucers! They may get their shape from hilly terrain or just the way the air is rising over flat terrain.
(Hope this helps) Sky
Which element easily loses one electron to form a positive ion? A. Magnesium (Mg) B. Lithium (Li) C. Nitrogen (N) D. Fluorine (F)
Answer: Lithium (Li)
Explanation:
Once it loses its only valence electron, there’s no longer a negative charge.
A community includes
A. all of the living organisms in a specific place at a specific time,
B. all plants, animals, minerals, and water in a specific place at a specific time,
C. only the plants in a specific place at a specific time.
D. only the animals in a specific place at a specific time.
Answer:
answer: A. all of the living organisms in a specific place at a specific time
Explanation:
how does the sun light affect earths climate
Answer:
The Sun powers life on Earth; it helps keep the planet warm enough for us to survive. It also influences Earth’s climate: We know subtle changes in Earth’s orbit around the Sun are responsible for the comings and goings of the past ice ages. But the warming we’ve seen over the last few decades is too rapid to be linked to changes in Earth’s orbit, and too large to be caused by solar activity
Explanation:
How do the particles of a gas differ from the particles of a solid?
Answer:
Gas is more open particles
Explanation: gas can flow
List and describe the steps of energy transfers that occur that allow a digital recording to be played through a speaker and ultimately become sound waves.
Answer:
1) Sound waves are stores as electrical signal in the digital recording.
2) the electrical signal of the digital recording is transcribed and sent to the voice coils.
3) the voice coil changes this electrical signal into varying magnetic fields.
4) The magnetic field pushes and pulls the diaphragm of the speakers.
5) the pushing and pulling of the diaphragm generates sound waves in the speaker.
please helpppppppppp
Select the TRUE statements about the carbon cycle
The carbon cycle is the process in which carbon travels from the atmosphere into organisms and the Earth and then back into the atmosphere.
Plants take carbon dioxide from the air and use it to make food.
Animals eat food and the carbon is stored in their bodies or released during cellular respiration.
Water (H2O) is cycled around the Earth
the carbon cycle is the process in which carbon travels from the atmosphere into organisms and the earth and then back into the atmosphere
What is the meaning of the red moon??
Answer:
the red moon occurs during lunar eclipse
Explanation:
The reddish coloration arises because sunlight reaching the Moon must pass through a long and dense layer of Earth's atmosphere, where it is scattered
________________ substances have an equal amount of H+ and OH- ions in solution.
Answer:
Water, and other neutral
Explanation:
That means those substances have pH = 7.
When the amount of H+ is more than the amount of OH- in solution, the substance is acidic ( eg.: Lemon juice ). pH < 7
When the amount of H+ is less than the amount of OH- in solution, the substance is basic ( eg.: Baking soda ). pH > 7
Why is the reaction SO2 + H20 → H2SO2 not balanced?
A. The oxygen atoms are in two molecules on one side, but one in
the other.
O
B. There are more molecules on one side than on the other.
O
C. There are more oxygen atoms on one side than on the other.
O
D. The sulfur atom is in different places in reactant and product
molecules
SUBMIT
Answer: C
# The main reason why the reaction above can not be balanced is:
This chemical reaction SO2 + H2O -> H2SO2 is not correctly written.
It must be: SO2 + H2O -> H2SO3
Explanation:
Note 1:
H2SO2 can be produced by the other chemical reaction:
2H2O + SCl2 -> 2HCl + H2SO2
....
Note 2: Answer A is false
As you can see in the reaction SO2 + H2O -> H2SO3, the oxygen atoms are in two molecules on one side, but one in the other - However, this reaction is written correctly.
Note 3: Answer D is false
Of course the Sulfur atom must be placed in different places: in reactant and product molecules.
Note 4: Answer B is false
There are different kinds of chemical reactions, and this is normal that there are more molecules on one side than on the other.
The answer is C
The correct way to balance the reaction, would be to write it as SO2 + H2O → H2SO3
Answer A is incorrect.
The oxygen atoms in the reaction SO2 + H2O -> H2SO3 are in two compounds on one end but on the other, it is in just one.
Answer D is wrong.
The sulfur atom has to be in the reactants and the products.
Answer B is not correct.
There are many types of chemical reactions . One side commonly has more atoms than the other.
balancing equations
Answer:
4. 1HCL + 1NAOH- I NACL+1H2O
Explanation:
there is 2 hydrogens on the left side of the equation, balancing out to the other side of the equation. everything else would be balanced out too
What is the mole fraction of Ba(OH)2 in an aqueous solution that contains 22.8% Ba(OH)2 by mass?
Answer:
0.03
Explanation:
22.8 g Ba(OH)2 (1 mol Ba (OH)2/ 171.34 g) = 0.133 mol Ba (OH)2
77.2 g H2O (1 mol H2O/18 g) = 4.29 mol H2O
X= molar fraction= mol Ba(OH)2/ mol total
X= 0.133/ (0.133+4.29) = 0.03
0.03 is the mole fraction of [tex]Ba(OH)_2[/tex] in an aqueous solution that contains 22.8% [tex]Ba(OH)_2[/tex] by mass.
What is a mole fraction?The ratio of the number of moles of one component of a solution or other mixture to the total number of moles representing all of the components.
Moles of [tex]Ba(OH)_2[/tex]
Moles = [tex]\frac{mass}{molar \;mass}[/tex]
Moles = [tex]\frac{22.8 g Ba(OH)_2}{171.34 g}[/tex]
= 0.133 mol [tex]Ba (OH)_2[/tex]
Moles of [tex]H_2O[/tex]
[tex]Moles = \frac{mass}{molar \;mass}[/tex]
[tex]Moles = \frac{77.2 g H_2O}{18 g}[/tex]
= 4.29 mol [tex]H_2O[/tex]
The mole fraction of [tex]Ba(OH)_2[/tex]
[tex]\frac{mol Ba(OH)_2}{total \;mol}[/tex]
= 0.03
0.03 is the mole fraction of [tex]Ba(OH)_2[/tex] in an aqueous solution that contains 22.8% [tex]Ba(OH)_2[/tex] by mass.
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Which of these Electromagnetic waves has the most kinetic energy and can be
dangerous?
O radio waves
O gamma rays
O ultraviolet waves
O visible light
Answer:
Gamma Rays.
Explanation:
Gamma-ray photons have the highest energy in the EMR spectrum and their waves have the shortest wavelength.
Is the equation Zn+HCl > ZnCL2+H2 unbalanced or balanced
Answer:
unbalanced
Explanation:
Cl and H have an extra atom
- Hope that helps! Please let me know if you need further explanation.
Review the following chemical equation: Find the molar ratio between C6H6 to
carbon dioxide, CO2. 2C6H6 + 1502 YEILDS 6H20 - 12C02
Answer:
[tex]\frac{1}{6}[/tex]
Explanation:
Molar ratio is defined as the ratio of number of moles of reactants or products in a balanced chemical equation.
In this balanced equation, the number of C6H6 molecules react to form 12 CO2 molecules.
Thus, the molar ratio between C6H6 to carbon will be equal to 2 moles of C6H6 divided by 12 moles of CO2
[tex]\frac{2}{12}\\\frac{1}{6}[/tex]
