Answer:
1.533 moles Au
Explanation:
To find the moles from atoms, you just use Avogadro's number (6.02214076×10^23 mol^-1) and divide by it. Hope this helped!
Answer:
[tex]\boxed {\boxed {\sf 1.53 \ mol \ Au}}[/tex]
Explanation:
We are asked to find how many moles of gold are in 9.23 *10²³ atoms of gold.
Avogadro's Number or 6.022 *10²³ is used to convert atoms to moles. This is the number of particles (atoms, molecules, formula units, etc.) in 1 mole of a substance. In this case, the particles are atoms of gold.
We convert using dimensional analysis. Set up a conversion factor using Avogadro's Number.
[tex]\frac {6.022 \times 10^{23} \ atoms \ Au}{ 1 \ mol \ Au}[/tex]
We are converting 9.23 * 10²³ atoms of gold to moles, so we multiply by this value.
[tex]9.23 \times 10^{23} \ atoms \ Au *\frac {6.022 \times 10^{23} \ atoms \ Au}{ 1 \ mol \ Au}[/tex]
Flip the conversion factor so the units of atoms of gold cancel.
[tex]9.23 \times 10^{23} \ atoms \ Au *\frac { 1 \ mol \ Au}{6.022 \times 10^{23} \ atoms \ Au}[/tex]
[tex]9.23 \times 10^{23} *\frac { 1 \ mol \ Au}{6.022 \times 10^{23}}[/tex]
[tex]\frac {9.23 \times 10^{23} }{6.022 \times 10^{23} } \ mol \ Au[/tex]
[tex]1.53271338426 \ mol \ Au[/tex]
The original measurement of atoms has 3 significant figures, so our answer must have the same. For the number we found, that is the hundredth place. The 2 in the thousandth place tells us to leave the 3.
[tex]1.53 \ mol \ Au[/tex]
9.23 *10²³ atoms of gold is equal to approximately 1.53 moles of gold.
please explain me answer a b c d
Answer:
I don't know the answers of chemistry if you have an entrance question of maths so I can
[tex]\rule{2000pt}{1000000pt}[/tex]
What does Bromine-80 decays by beta decay to?
Answer:
beta to Kr-80 or Se-80
Explanation:
sorry if wrong
. What mass of ammonium chloride must be added to 250. mL of water to give a solution with pH
4.85? [Kb(NH3) = 1.8 x 10-1
a. 4.7 g
b. 75 g
c.2.3 x 10-ºg
d. 19 g
e.10g
The mass of ammonium chloride that must be added is : ( A ) 4.7 g
Given data :
Volume of water ( V ) = 250 mL = 0.25 L
pH of solution = 4.85
Kb = 1.8 * 10⁻⁵
Kw = 10⁻¹⁴
Given that the dissolution of NH₄Cl gives NH₄⁺⁺ and Cl⁻ ions the equation is written as :
NH₄CI + H₂O ⇄ NH₃ + H₃O⁺
where conc of H₃O⁺
[ H₃O⁺ ] = [tex]\sqrt{Ka.C}[/tex] and Ka = Kw / Kb
∴ Ka = 5.56 * 10⁻¹⁰
Next step : Determine the concentration of H₃O⁺ in the solution
pH = - log [ H₃O⁺ ] = 4.85
∴ [ H₃O⁺ ] in the solution = 1.14125 * 10⁻⁵
Next step : Determine the concentration of NH₄CI in the solution
C = [ H₃O⁺ ]² / Ka
= ( 1.14125 * 10⁻⁵ )² / 5.56 * 10⁻¹⁰
= 0.359 mol / L
Determine the number of moles of NH₄CI in the solution
n = C . V
= 0.359 mol / L * 0.25 L = 0.08979 mole
Final step : determine the mass of ammonium chloride that must be added to 250 mL
mass = n * molar mass
= 0.08979 * 53.5 g/mol
= 4.80 g ≈ 4.7 grams
Therefore we can conclude that the mass of ammonium chloride that must be added is 4.7 g
Learn more about ammonium chloride : https://brainly.com/question/13050932
Could a single person or animal be a point source pollution
Answer:
the main cause of pollution is mankinds work like gases and extreme heat caused by factories and cars and littering is also caused by people's careless throwing away so In term man kind is responsible for the pollution
Explanation:
Write the symbol for every chemical element that has atomic number less than 13 and atomic mass greater than 17.2 u.
2 FeCl2
+ 13 KClO4
+ H2
SO4
→ 2 Fe(ClO3
)3
+
K2
SO4
+ 11 KClO3
+ H2
O
Calculate the grams of KClO3
arising from the
reaction of 2.50 g of KClO4
with 150 mg of FeCl2
in excess of H2
SO4
.
Taking into account the reaction stoichiometry and limiting reagent, 0.7977 grams of KClO₃ are formed from the reaction of 2.50 g of KClO₄ with 150 mg of FeCl₂ in excess of H₂SO₄.
In first place, the balanced reaction is:
2 FeCl₂ + 13 KClO₄ + H₂SO₄ → 2 Fe(ClO₃)₃ + K₂SO₄ + 11 KClO₃ + H₂O
By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:
FeCl₂: 2 molesKClO₄: 13 moles H₂SO₄: 1 moleFe(ClO₃)₃: 2 moles K₂SO₄: 1 mole KClO₃: 11 moles H₂O: 1 moleThe molar mass of the compounds is:
FeCl₂: 126.75 g/moleKClO₄: 138.55 g/mole H₂SO₄: 98 g/moleFe(ClO₃)₃: 306.2 g/moleK₂SO₄: 174.2 g/moleKClO₃: 122.55 g/moleH₂O: 18 g/moleThen, by reaction stoichiometry, the following mass quantities of each compound participate in the reaction:
FeCl₂: 2 moles× 126.75 g/mole= 253.5 gramsKClO₄: 13 moles× 138.55 g/mol= 1801.15 grams H₂SO₄: 1 mole× 98 g/mole= 98 gramsFe(ClO₃)₃: 2 moles× 306.2 g/mole= 612.4 gramsK₂SO₄: 1 mole× 174.2 g/mole= 174.2 gramsKClO₃: 11 moles× 122.55 g/mole= 1348.05 gramsH₂O: 1 mole× 18 g/mole= 18 grams
The limiting reagent is one that is consumed first in its entirety, determining the amount of product in the reaction. When the limiting reagent is finished, the chemical reaction will stop.
To determine the limiting reagent, it is possible to use the reaction stoichiometry of the reaction and a simple rule of three as follows: if by stoichiometry 1801.15 grams of KClO₄ reacts with 253.5 grams of FeCl₂, if 2.50 grams of KClO₄ react how many mass of FeCl₂ will be needed?
[tex]mass of FeCl_{2}=\frac{2.50 grams of KClO_{4} x253.5 grams of FeCl_{2}}{1801.15 grams grams of KClO_{4}}[/tex]
mass of FeCl₂=0.35 grams
But 0.35 grams of FeCl₂ are not available, 150 mg= 0.150 grams (being 1000 mg= 1 grams) are available. Since you have less mass than you need to react with 1801.15 grams of KClO₄, FeCl₂ will be the limiting reagent.
Then the following rule of three can be applied: if by reaction stoichiometry 253.5 grams of FeCl₂ form 1348.05 grams of KClO₃, 0.150 grams of FeCl₂ form how much mass of KClO₃?
[tex]mass of KClO_{3}=\frac{0.150 grams of FeCl_{2}x1348.05 grams of KClO_{3} }{253.5grams of FeCl_{2} }[/tex]
mass of KClO₃= 0.7977 grams
Then, 0.7977 grams of KClO₃ are formed from the reaction of 2.50 g of KClO₄ with 150 mg of FeCl₂ in excess of H₂SO₄.
Learn more about reaction stoichiometry:
brainly.com/question/24741074 brainly.com/question/24653699 brainly.com/question/23871710Which best explains why a person can tell the difference between a whisper and a yell?
O Sound waves turn into chemical signals that indicate certain sounds.
Different vibrations in the ear cause the bras o interpret different sounds.
The fluid in the cochlea picks up electrical signals for the intensity of sound.
The eyes see what is making the noise and help the brain process the sound.
Answer:
The difference is the louder the sound the bigger the waves and your ears collect the sound waves and brings it to you brain
Explanation:
Answer:
Hey! The correct answer is D.) Different vibrations in the ear cause the brain to interpret different sounds.
Explanation:
I got a low score on the test but yeah I got that one correct so It's D
Which of these is a characteristic of warm air?
It transfers energy through radiation.
Its molecules are far apart.
It sinks due to convection.
It cools the land below it.
Answer: B.
Explanation:
Warm air molecules are far apart, while cool air molecules are packed closer together.
Answer: A It Transfers energy through radiation
Explanation: I jut got done with the exam 15 min ago
The ion of aluminum is
Al+
Al2-
Al2+
Al3+
Al3-
Answer:
A13+
Explanation:
I took a test that had this question.
Which statement describes a homogeneous catalyst?
It is in a gaseous phase only.
It is in the same phase as the reactants.
It is completely consumed by reactants.
It forms different products than the uncatalyzed reaction forms.
Answer:
it is in the same phase as the reactants
The statement describes a homogeneous catalyst is,
It is in the same as the reactants.So, option B is correct one.
What is homogeneous catalyst?The homogeneous catalyst is refer to catalytic system.In this, the phase of substrates for a reaction and catalytic components are same.Mainly it is in liquid phase.Example: Production of acetic acidWhat is catalyst?
The substance which increases the rate of the reaction without being itself change at the end of the reaction is called catalyst.
learn about homogeneous catalyst,
https://brainly.com/question/4249142
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iDENTIFY THE NAME OF THE ELEMENTS OF THE ATOMS ABOVE
Answer:
oxygen carbon hydrogen nitrogen
Explanation:
identified by the number of protons in its atoms
which is the compound that has the higher boiling point and explain why we see the
differences we do
a. ethane vs. ethene
b. heptyne vs. pentyne
c. octane vs. octanal
thanks!
Answer:
b I think it is the correct answer
What are the five different types of leaves? Subject: science
Answer:
Needle and Scale Leaves. This kind of leaves are mostly found in 'evergreen' trees. ...
Lanceolate Leaf. ...
Oblong Leaf. ...
Linear Leaves. ...
Cordate Leaves.
Explanation:
Answer:
Broad
Flat Leaves.
Needle and Scale Leaves.
Oblong Leaf.
Cordate Leaves.
Explanation:
A 4.190 g sample of an oxide of chromium contains 2.179g of chromium, what is its empirical formula?
a. CrO2
b. Cr2O
c. CrO3
d. Cr2O3
I'm not sure but I think it is C. CrO3
Safety considerations
• Sodium Hydroxide (please insert one statement of caution from MSDS)
Answer:
d took the test
Explanation:
Which of these objects will most likely float?
Answer:
plastic,palstic bottle,balloon,cap of water bottle,plastic slippers and plastic comb.
Explanation:
hope it helps :D
The results of Rutherford's gold foil experiment gave him the evidence to conclude that the center of an atom was A) called the nucleus. B) neutral and relatively small. C) positively charged and relatively small. D) a densely packed area containing both positive and negative particles.
Answer:
c)
Explanation:
because alpha particles can go through it
calculate the number of molecules in 4.48dm3 of hydrogen at STP
Answer: 1 more of hydrogen =22.4dm3
X moles of hydrogen =4.48dm3
22.4dm3x = 4.48dm3
4.48dm3\22.4dm3
X=0.2 moles
Explanation: 1 volume of hydrogen at STP is 22.4dm3
Need ASAP will give brainlist
Answer:
i think the answer will be C.
Explanation:
correct me if im wrong
loveya
2.
The highest part of the wave is called the ____________.
Group of answer choices
A. best
B. crest
C. top
D. trough
Answer:
B. crest
Explanation:
The highest part of a wavelength is called the crest, meanwhile, the lowest part is the trough.
Answer:
b
Explanation:
it's highest because it have the most higher wave
Help asapp plzz!!!!
Answer:
Determining what data to collect.
Explanation:
Explain the verse below in your own words in a little summary.
Hebrews 11:7
God had warned Noah of the flood and directed him to build an ark. Noah had faith in God and began building.
Answer:
God Warned Noah for the Flood comindg to Earth to wash away all the bad people's lives and god also said get couple animals girls and boys then build an ark then bring your family and food there to then noah had a faith in god so he obey and start builind the ark in a top of a mountain
Explanation:
Hebrews 11:7
help plzzzzzzzzzzzzzzzzz
Answer:
C
I hope that this helps.
At a certain temperature, the equilibrium pressures of NO2 and N2O4 are 1.4 bar and 0.46 bar, respectively. If the volume of the container is doubled at constant temperature, what would be the partial pressures of the gases when equilibrium is re-established?
The partial pressure of NO₂ at equilibrium is 0.70 bar and the partial pressure of N₂O₄, at equilibrium is 0.23 bar.
Let x be the mole fraction of NO₂ and x' be the mole fraction of N₂O₄.
The total pressure according to Dalton's law of partial pressure is the sum of the partial pressures of each gas.
Let P be the total pressure of the gases, P' be the partial pressure of NO₂ = 1.4 bar and P" be the partial pressure of N₂O₄ = 0.46 bar.
So, P = P' + P"
= 1.4 bar + 0.46 bar
= 1.86 bar
Since P' = xP
x = P'/P
= 1.4 bar/1.86 bar
= 0.753
Also, P" = xP
x' = P"/P
= 0.46 bar/1.86 bar
= 0.247
Now, since the volume of the container is doubled at constant temperature, we use Boyle's law to determine the new pressure. P₁.
Boyle's law states that the pressure of a given mass of gas is inversely proportional to its volume provided the temperature remains constant. It is written mathematicaly as PV = constant
So, PV = P₁V₁
P₁ = (V/V₁)P
Since V/V₁ = 1/2
P₁ = (V/V₁)P
P₁ = P/2
P₁ = 1.86/2 bar
P₁ = 0.93 bar
So, the new partial pressure of NO₂, P₂ = xP₁
= 0.753 × 0.93 bar
= 0.70 bar
The new partial pressure of N₂O₄, P₃ = x'P₁
= 0.247 × 0.93 bar
= 0.23 bar
So, the partial pressure of NO₂ at equilibrium is 0.70 bar and the partial pressure of N₂O₄, at equilibrium is 0.23 bar.
Learn more about partial pressure here:
https://brainly.com/question/19813237
The N2O decomposition, 2 N2O (g) → 2 N2 (g) + O2 (g), is a zero order reaction that has a reaction rate constant of 2.00 × 10−3 M/s. Initially, 2.00 moles of N2O gas are infused into a 1.00 L vessel at 300. K.Calculate the pressure inside the vessel at 100. seconds after the start of the reaction. Temperature is held constant.
Answer:
2.00n2g
Explanation:
hope its attachments
Consider the chemical formula for calcium chlorate: Ca(ClO3)2
How many of each of these atoms is in a molecule of calcium chlorate?
I hope it help u =)
Brainliest answer pls
Why must labs that use mercury thermometers calculate Kelvin ?
Answer:
because those are the only thermometers that are truly accurate for kelvins
Explanation:
The Kelvin temperature in thermometers is used by scientists because it provides a temperature where zero indicates the complete absence of thermal energy.
What is the Kelvin scale?All thermometers have a scale on them that we use to find the temperature, known as a temperature scale. Kelvin proposed that the temperature interval from the ice point to the steam point be defined as 100° containing earlier centigrade scales.
Lord Kelvin had given an absolute temperature scale based on the Carnot cycle. The zero point is 273.15 on Kelvin’s scale below that of the Celsius scale.
On the kelvin scale, Each division is called a Kelvin (K) and is equal to a degree on the Celsius scale. On the Celsius scale, zero degrees is the freezing point of water while on the Kelvin scale the zero point is at absolute zero temperature.
Therefore, 0 K is equal to - 273.15°C, and 0°C is equal to 273.15 kelvins. A mathematical expression that gives the relation between the Celsius and Kelvin scales:
Temperature (K) = Temperature (°C) + 273
Learn more about Kelvin scale, here:
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How does the water cycle contribute to the "brown ocean" effect?
Answer:
Hurricanes and tropical storms gain their power from heated water evaporating from the ocean.
Explanation:
Brown Water Effect The brown ocean effect is an observed weather phenomenon involving some tropical cyclones after landfall. Normally, hurricanes and tropical storms lose strength when they make landfall, but when the brown ocean effect is in play, tropical cyclones maintain strength or even intensify over land surfaces.An electrolysis reaction is
A) spontaneous
B) exothermic
C) non-spontaneous
D) hydrophobic
Answer:
it's non-spontaneous
Explanation:
I hope it helps you
Which of the following statements is true about CO?
а
The carbon and oxygen share electrons.
b
Carbon is the cation and oxygen is the anion.
с
It is the element cobalt.
d
Its name is monocarbon monoxide.
e
none of these
Answer:
it is the element cobalt with atomic number 27