Answers
Answer:
Al2O3
Explanation:
Empirical formula is found by converting percent composition into a mole ratio.
First, assume you have a 100g sample of the substance. This allows you to make your percent composition into grams.
100% = 100g
53% = 53g Al
47% = 47g O
Next, divide each substance's mass by their molar mass. This converts your number to moles.
[tex]53g Al / 27g Al = 1.96 mol\\\\47g O/16g O = 2.93mol[/tex]
Next, divide both mol answers by the smallest number of moles.
[tex]1.96mol/1.96mol = 1\\2.93mol/1.96mol = 1.5[/tex]
Usually, these answers would be your subscripts for your empirical formula. However, we cannot have a decimal subscript, so we will multiply our answers by a factor of 2 to get to a whole number. This gives us 2 moles of Al and 3 moles of oxygen, or a formula of Al2O3.
Considering the definition of empirical formula, the correct answer is the second option: the empirical formula is Al₂O₃.
Definition of empirical formulaThe empirical formula is the simplest expression to represent a chemical compound, which indicates the elements that are present and the minimum proportion in whole numbers that exist between its atoms, that is, the subscripts of chemical formulas are reduced to the most integers. small as possible.
Empirical formula in this caseAssuming a 100 grams sample, the percentages match the grams in the sample. So you have 53 grams of Al and 47 grams of O.
Then it is possible to calculate the number of moles of each atom in the molecule, taking into account the corresponding molar mass:
Al: [tex]\frac{53 grams}{27 \frac{grams}{mole} }[/tex]= 1.9629 moles
O: [tex]\frac{47 grams}{16 \frac{grams}{mole} }[/tex]= 2.9375 moles
The empirical formula must be expressed using whole number relationships, for this the numbers of moles are divided by the smallest result of those obtained. In this case:
Al: [tex]\frac{1.9629 moles}{1.9629 moles}[/tex]= 1
O: [tex]\frac{2.9375 moles}{1.9629 moles}[/tex]≅ 1.5
You cannot have a decimal subscript, so you will multiply our answers by a factor of 2 to get to a whole number:
Al: 1× 2= 2
O: 1.5× 2= 3
Therefore the Al:O mole ratio is 2: 3
Finally, the correct answer is the second option: the empirical formula is Al₂O₃.
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Related Questions
what is the first element in the periodic table?
Answers
Answer:
the first element on the table is Hydrogen
Experimental Data
Enter the data shown in the video for Unknown Sulfate #23 below or where required, calculate the value from your data:
Mass of empty 250-mL beaker (from video) =129.536g
Mass of 250-mL beaker and unknown sulfate (from video) =129.840g
Mass of unknown sulfate (calculated) =0.304g
Mass of empty crucible (from video) =10.320g
Mass of crucible and barium sulfate (from video) =10.723g
Mass of barium sulfate =0.403g
Calculations and Conclusions
Calculate the mass of sulfate in the unknown sample:
Mass of sulfate in unknown =_______g
Calculate the percentage by mass of sulfate in the unknown sample:
Mass percent of sulfate in unknown =
%
The cation in the unknown sulfate is one of the following:
Al3+ Na+ Ni2+ K+ NH4+ Cd2+
For each of these six cations, write the formula of its sulfate, and calculate the percentage mass of sulfate in the compound.
Formula of aluminum sulfate =
Mass percent of sulfate in aluminum sulfate =
%
Formula of sodium sulfate =
Mass percent of sulfate in sodium sulfate =
%
Formula of nickel(II) sulfate =
Mass percent of sulfate in nickel(II) sulfate =
%
Formula of potassium sulfate =
Mass percent of sulfate in potassium sulfate =
%
Formula of ammonium sulfate =
Mass percent of sulfate in ammonium sulfate =
%
Formula of cadmium sulfate =
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Answers
How many moles of titanium are in a sample containing 2.8 x 10^24 atoms?
1) 1.69 x 10^48
2) 4.65 x 10^43
3) 4.65
4) 0.0465
5) 48
Answers
Answer:
4.65 moles
Explanation:
To calculate this, we can use Avogradro's Number: 6.022*10^23
[tex]2.8*10^2^4*\frac{1mole}{6.022*10^2^3} =4.65mol[/tex]
So, there are 4.65 moles in 2.8*10^24 atoms of Ti
What happens to the water molecules when water at 24°C is cooled to 0°C
and freezes?
pls help its due tmr
giving brainliest
Answers
When the following equation is balanced, what is the coefficient of oxygen?
C2H5OH() + O2(g) --> CO2(g) + H2O()
Answers
Answer:
The answer is 3
C2H5OH + O2 CO2 +H2O (unbalanced)
C2H5OH +3O2(g). 2CO2(g)+3H2O(balanced)
According to the balanced chemical equation, C₂H₅OH + 3 O₂[tex]\rightarrow[/tex] 2 CO₂ + 3 H₂O the coefficient of oxygen is three.
What is chemical equation?Chemical equation is a symbolic representation of a chemical reaction which is written in the form of symbols and chemical formulas.The reactants are present on the left hand side while the products are present on the right hand side.
A plus sign is present between reactants and products if they are more than one in any case and an arrow is present pointing towards the product side which indicates the direction of the reaction .There are coefficients present next to the chemical symbols and formulas .
The first chemical equation was put forth by Jean Beguin in 1615.By making use of chemical equations the direction of reaction ,state of reactants and products can be stated. In the chemical equations even the temperature to be maintained and catalyst can be mentioned.
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Need help with chemistry!
Answers
Answer:
c
Explanation:
I am not sure but this is the answer I can provide now
Why is it important for some skateboarding ramps to be tall? Use the terms "potential energy" and "kinetic energy" in your answer. plsssssss help meeee Plzzz in kids words
Answers
Explanation:
Yw ❤
Shorter people have a lower center of gravity. Taller people have a higher center of gravity. A lot of skateboarding tricks depend on the center of gravity.
What is kinetic energy?
Kinetic energy is a form of energy it possess when any object or person is in motion . It can be defined as the work needed to be done to produce a motion in a object from rest position.
If we want to acceleration in an object then we must apply a force on a object to give motion so we can say that we required to do work for acceleration and then we can say that required is equal to kinetic energy.
Mathematically
Kinetic energy =1/2mv^2
Where
m = mass of object.
v = velocity of object
Kinetic energy is vector quantity it means that it have both i.e magnitude and vector.
S.I unit of Kinetic energy is Joule.
Therefore, Shorter people have a lower center of gravity. Taller people have a higher center of gravity. A lot of skateboarding tricks depend on the center of gravity.
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How many mL of isopropyl alcohol solution (40% v/v) would contain 2.5 mL of isopropyl alcohol? Report your answer in mL
Answers
Answer:
[tex]V_{solution}=6.25mL[/tex]
Explanation:
Hello there!
In this case, given the by-volume percent and the volume of isopropyl alcohol as the solute, we can compute the volume of the solution via:
[tex]\% v/v=\frac{V_{solute}}{V_{solution}} *100\%\\\\V_{solution}=\frac{V_{solute}}{\% v/v} *100\%[/tex]
Now, we plug in the given data to obtain:
[tex]V_{solution}=\frac{2.5mL}{40\%} *100\%\\\\V_{solution}=6.25mL[/tex]
Best regards!
Which do all cells need in order to function?
oxygen
water
carbon dioxide
offspring
Answers
Answer:
oxygen is the correct answer
Explanation:
you need oxygen in order to breath, eat, drink, and many other stuf! hope i helped!
HELP!
The law of conservation of energy states:
A. Energy increases exponentially with times
B. Total energy decreases due to energy output.
C. Energy cannot be created or destroyed.
D. Energy always remains in the same form.
Answers
Answer:
C
Explanation:
energy cannot be created or destroyed like solar energy for instance. it is already energy because it comes from the sun and for other reason.
Hope this helps!
A 59.7 g piece of metal that had been submerged in boiling water was quickly transferred into 60.0 mL of water initially at 22.0 °C. The final temperature is 28.5 °C. Use these data to determine the specific heat of the metal. Use this result to identify the metal.
Answers
!!!!!!!’!!!!!!!!!!!!!!!!!!!!!!!’
PLZ HELP NO LINKS
What cell structure is necessary for photosynthesis?
xylem
chloroplasts
cell walls
roots
Answers
and photosynthesis are both needed
You read a primary source and a secondary source that discuss the same
experiment. There is a difference in the conclusions made by these two
sources. Which should you trust more, and why?
A. The primary source, because it is more confusing
B. The secondary source, because it is published in a well-respected
newspaper
C. The secondary source, because it is easier to read
D. The primary source, because it is written by the scientist who did
the work
Answers
Answer:
i think it's D tbh, just cus it was the scientist who did the work
Answer:
It depends on secondary sources and references of that secondary source. If it references just that primary source I would compare both of them and see the difference between them. Generally primary sources are more reliable but this situation is different.
I need this like NOW
An area on the map where we might see strong winds is:
Question 5 options:
near Maine
near California
near Washington D.C.
near Kansas City
Answers
Gallium (Ga, 69.723 g/mol) is a metalloid obtained from its salts during the smelting of ores of other elements, like Zinc, Ga has broad applicability in the electronics industry. It is also used as a safe replacement for mercury in thermometers as it melts at 29.8 oC and has a heat of fusion of 5.59 kJ/mol. What is the entropy change of of gallium in as it melts when placed on a surface at 29.8 oC?
Answers
Answer:
4.255 J/ K
Explanation:
Given data :
mass of Gallium = 16 gm
molar mass = 69.723 g/mol
hence no of moles = 16 / 69.723 = 0.23 moles --------- ( 1 )
Δh ( heat fusion ) = 5.59 KJ/mol
Temperature = 29.8°C = 302.8 k
Determine the entropy change of gallium
Δs ( entropy change ) = heat fusion / temperature
= ( 5.59 * 1000) J/mol / 302.8 = 18.46 J/k*mol
Hence entropy change of gallium
= Δs * no of Gallium moles
= 18.46 * 0.23 = 4.255 J/ K
he image shows two air fronts moving in a region. The cold front is moving faster than the warm front.
Which will likely happen if the cold front continues to advance faster than the warm front?
Cold air will pass over the warm air, causing dry weather in the region.
Cold air will pass over the warm air, causing dry weather in the region.
Cold air will push up the warm air, resulting in heavy rainfall in the region.
Cold air will push up the warm air, resulting in heavy rainfall in the region.
Cold air will push up the warm a
Answers
Answer:
Cold air will push up the warm air, resulting in heavy rainfall in the region.
Help please
Lunar eclipses happen when the _____.
moon passes between the Earth and the sun
Earth passes between the sun and the moon
sun passes between the Earth and the moon
Answers
Answer:
mook passes between the earth and sun
Which of the following is the best way to make a conclusion?
A. The experiment must be manipulated until the results show what you want
B. Estimate results to where they should be
C. Choosing the results you like
D. Comparing data from the experiment to the prediction of the hypothesis
Answers
Fill in the missing information:
1. Complete Nuclear Symbol ________
2. Atomic # ________
3. Mass number ________
# Protons 22
# Electrons 18
# Neutrons 26
4. Charge _________
Answers
Answer: 1. Complete Nuclear Symbol : [tex]_{22}^{48}{Ti^{4+}}[/tex]
2. Atomic number : 22
3. Mass number : 48
4. Charge : 4 +
Explanation:
Atomic number is equal to the number of protons.
Mass number is the sum of number of neelectrons. utrons and number of protons.
Given : no of protons = 22 , thus atomic number = 22
Mass number = number of neutrons + number of protons
Mass number = 26 + 22 = 48
Also for a neutral atom , the number of protons is equal to the number of electrons. But here electrons are 4 less than protons, which means the atom has lost 4 electrons and thus will have a charge of 4+.
The atomic number is specific to an element, and the element with atomic number 22 is Titanium (Ti). The representation is [tex]_{22}^{48}{Ti^{4+}}[/tex]
Many power plants produce energy by burning carbon-based fuels, which also produces carbon dioxide. Carbon dioxide is a greenhouse gas, so over-production can have negative effects on the environment. Use enthalpy of formation data to calculate the number of moles of CO2(g) produced per megajoule of heat released from the combustion of each fuel under standard conditions (1 atm and 25 °C).
Answers
Answer:
2.54 molMJ-1
Explanation:
The formation of CO2 is according to the equation;
C(s) + O2(g) -------> CO2
ΔHreaction = ΔHCO2 - [ΔHO2 + ΔHC]
ΔHO2 and ΔHC = 0 KJ
ΔHCO2 = -393.5 KJ
Hence;
ΔHreaction = -393.5 KJ - 0 KJ
ΔHreaction = -393.5 KJ
1 mol of CO2 yields -393.5 KJ/mol
The negative sign only means that heat was evolved in the process.
nCO2 = 1 mol CO2/393.5 KJ * 1 * 10^3 KJ/1MJ
nCO2 = 2.54 molMJ-1
how many moles are 20 grams of Helium ?
Answers
Answer: The correct answer is 5.00 moles
Explanation:
Please please help me
Answers
Answer:
I agree with Omar because it depends on what the charge of the object and magnet is. If the magnet is negative and the object is positive, they will pull together. If the magnet is negative and the object is negative then they will pull apart.
Explanation:
Help!!
Which of the following tends to have increased solubility from increased pressure?
A gas in a liquid.
a liquid in a solid.
a solid in a gas.
A solid in a liquid.
Answers
Answer:
a solid in a gas
Explaination:
because soild will take a long while to dissolve into liquid by heating the soild with gas it will disslove quicker
What is the total pressure of a mixture of gases, with 23 atm, 10 atm, 16 atm, and 30 atm?
Answers
Which part of the body transports molecules from food and air to the cells of the body
Answers
Answer:
Molecules from food and molecules of oxygen move from the mouth and the nose to cells of the body through a series of blood vessels, including veins, arteries, and microscopically small blood vessels (capillaries), that extend throughout the body.
Explanation: This is right
Explanation: The circulatory system delivers oxygen and nutrients to cells and takes away wastes. The heart pumps oxygenated and deoxygenated blood on different sides. The types of blood vessels include arteries, capillaries and veins.
heat is the movement from areas of ___ temperature to areas of ___ temperature
Answers
Answer:
heat is the movement from areas of high temperature to areas of low temperature
how many moles of ag can be produced if 250g of CU are reacted with excess agNo3, according to the equation Cu(s) + 2AgNO3(aq) -> 2Ag(s) + Cu(NO3)2(aq)?
Answers
Answer:
[tex]250 \times \frac{1}{63.5} \times \frac{2}{1} = 7.874mol \: ag[/tex]
how would you measure out five moles of a gas?
Answers
What is the concentration of kl solution if 20.68g of solute was added to enough water to form 100ml solution?
Answers
Answer:
1.25 M
Explanation:
Step 1: Given data
Mass of KI (solute): 20.68 g
Volume of the solution: 100 mL (0.100 L)
Step 2: Calculate the moles of solute
The molar mass of KI is 166.00 g/mol.
20.68 g × 1 mol/166.00 g = 0.1246 mol
Step 3: Calculate the molar concentration of KI
Molarity is equal to the moles of solute divided by the liters of solution.
M = 0.1246 mol/0.100 L= 1.25 M
How many levels are in the classification system?
A: 7
B: 2
C: 4
D: 6
Answers
Answer:
7
Explanation:
There are seven major levels of classification: Kingdom, Phylum, Class, Order, Family, Genus, and Species.
So, the answer is option A.
Good luck