Answer:
a
Explanation:
Determine the mass of O(2-) ions in 3 mol of alumina (Al2O3). Molar mass of O = 16)
Considering the rule of three and molar mass of O, the mass of O²⁻ ions in 3 mol of alumina Al₂O₃ is 96 grams.
By multiplying the number of moles by the subscripts next to each atom, you get the amount of each element present in the compound. IIf the same atom appears more than once in the compound, you must add its amounts.
So, in 1 mole of Al₂O₃, you have 2 ions of O²⁻.
Then you can apply the following rule of three: if 1 mole of the compound contains 2 ions of O²⁻, 3 moles of the compound contains how many ions of O²⁻?
[tex]amount of ions of O^{2-} =\frac{3 moles of Al_{2} O_{3} x2 ions of O^{2-}}{1mole of Al_{2} O_{3} }[/tex]
amount of ions of O²⁻= 6 ions
Being the molar mass of O 16 g/mole, this is the amount of mass that a substance contains in one mole, then the mass of O²⁻ can be calculated as:
6 x 16 g/mole= 96 grams
Finally, the mass of O²⁻ ions in 3 mol of alumina Al₂O₃ is 96 grams.
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https://brainly.com/question/3588290?referrer=searchResultshttps://brainly.com/question/25873251?referrer=searchResultsa chemical reaction in which bonds are broken is usually associated with
the release of energy
What would be the partial pressure of nitrogen, PN2, in a room in which the total air pressure was 0.987 atm?
This problem is providing describing a room in which air has a total pressure of 0.987 atm and the partial pressure of nitrogen is asked, turning out to be 0.746 atm.
In such a case, we can start by looking at the provided table, which shows the composition of dry air in mass basis, which means we must convert the composition of nitrogen to mole fraction by knowing that the average molar mass of air is 28.9647 g/mol, and thus, we infer that the mole fraction of nitrogen in air is about 0.755 according to:
[tex]x_{N_2}=\frac{0.781*14.0067g/mol*2}{28.9647g/mol} =0.755[/tex]
Then, we recall the Dalton's law version that relates total pressure, partial pressure and mole fraction written for nitrogen:
[tex]P_{N_2}=x_{N_2}P[/tex]
Finally, we plug in the previously calculated mole fraction and the total pressure of air to obtain:
[tex]P_{N_2}=0.755*0.987 atm\\\\P_{N_2}=0.746atm[/tex]
Learn more:
(Gas laws) https://brainly.com/question/8511562(Dalton's law) https://brainly.com/question/14119417why does hydrogen fluoride have a high boiling point
The intermolecular bonding for HF is van der Waals, whereas for HCL, the intermolecular bonding is hydrogen. Since the van der Waals bond is stronger than hydrogen, HF will have a higher boiling temperature. Since the covalent bond is stronger than van der Waals, HF will have a higher boiling temperature.
How many moles of CO2 are produced from 15.6 g of NaHCO3?
Answer:
0.185moles
Explanation:
1mole of bicarbonate produces 1mole of CO2
so 0.185 mole produces 0.185 moles of CO2
Help me in the 10 the number. Clue- helium and hydrogen make up the first of these
Answer:
helium and hydrogen make up the first of these
the answer is period
Please help !!!!!!!!
1) Write the equation for the reaction between the hydrocarbon and bromine using fully displayed formulae for the hydrocarbon and the organic product.
2) The reaction between methane and bromine gas in the presence of UV light also causes the bromine to lose color.
(a) Write an equation for this reaction
(b) This reaction is described as a substitution reaction. whereas the reaction between X and bromine is an addition reaction. Using the equations you have already written , explain the difference between addition and substitution
Can someone please explain the steps to the correct answers?
Explanation:
1. b is correct because 10^-2 is 1/100. multiplying that by 1.862 is 0.01862
2. 6 feet 10 inches = 82 inches. multiplying 82 by 2.54 we get 208.28. there are only two sig figs so it's 210 cm, not 0.21 cm.
3. 25.2 x 39370 = 992000, which is 9.92 x 10^5.
In the conclusion to the snake mole lab, you have to convert 3.45 moles of (NH4)2S04 to
grams. What is the molar mass of (NH4)2504?
what is the molarity of a koh solution if 25.0 ml neutralizes 35.0 ml of a 0.200 m hcl solution?
If 25.0ml neutralizes 35.0 ml of a 0.200M HCl solution, the molarity of KOH solution is 0.28M
The reaction between KOH solution and HCl is written below.
[tex]HCl + KOH \rightarrow KCl + H_2O[/tex]
Volume of KOH, [tex]V_B[/tex] = 25.0 ml
Volume of HCl, [tex]V_A=35.0 ml[/tex]
Molarity of HCl, [tex]C_A=0.200 M[/tex]
Molarity of KOH, [tex]C_B=?[/tex]
Number of moles of HCl, [tex]n_A=1[/tex]
Number of moles of KOH, [tex]n_B=1[/tex]
The mathematical equation for neutralization reaction is:
[tex]\frac{C_AV_A}{C_BV_B} =\frac{n_A}{n_B}[/tex]
Substitute [tex]C_A=0.200 M[/tex], [tex]n_A=1[/tex], [tex]n_B=1[/tex], [tex]V_B[/tex] = 25.0 ml, and [tex]V_A=35.0 ml[/tex] into the equation above in order to solve for [tex]C_B[/tex]
[tex]\frac{0.2 \times 35}{C_B \times 25}=\frac{1}{1} \\\\25C_B=7\\\\C_B=\frac{7}{25} \\\\C_B=0.28M[/tex]
Therefore, the molarity of KOH solution is 0.28M
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I will give thanks, profile thanks, brainliest and 5 star
Answer: E.) C2N2H8
Explanation:
Answer:
E ) C2N2H8
Explanation:
Help me Please
Is boiling an egg a physical or a chemical change? Explain your answer.
Answer:
it's a chemistry change
Explanation:
this is because heat is causing permanent changes and can no longer be changed back to its original atate
what is the nature of the p-o bond in phosphorus pentoxide (p2o5)?
Answer:
the nature of the bond is covalent.
covalent bonds are bonds between 2 NON-METAL elements. since phosphorus and oxygen are both non-metals, the bond formed between them is covalent.
hope this answers your question!
In an investigation that uses the scientific method, which step immediately follows making a hypothesis?
summarizing the results
asking a question
making observations
designing an experiment
C????
Answer:
The answer is designing an experiment
Explanation:
Since we already have a hypothesis, we need to test the hypothesis and this is done by designing an experiment that will do this test.
HELP ME PZLMSMS
E
D
D
F
F
Answer:
10.C
11.B
15.A
Explanation:
what has fewer organisms then a domain but it also has more organisms then a phylum
Answer:
a species
Explanation:
(07.05 HC A scientist investigating electrically-charged objects has decided to test if the number of times you rub a cloth against a balloon increases the amount of time it will stick to the wall. She wrote down her variables in a table. Variable Description Test The numbers of times she rubbed the cloth against the balloon Outcome The length of times the balloon sticks to the wall Control The cloth used in the experiment What would be her hypothesis for this experiment? (2 points) If you stick the balloon to a wall, then it will become electrically charged and stay there for a long period of time If you change the cloth used to change a balloon
Answer: the answer is b
Explanation:I took the test and got it
pls mark as brainliest if correct for you
Which of the following best describes a balanced reaction?
A) A reaction that has the sam number and type of atoms on each side of the equation
B) A reaction that has the same number of atoms on each side of the equation
C) A reaction that has the and type of atoms on each side of the equation
D) A reaction that has the same number of molecules on each side of the equation
Answer:
A reaction that has the same number and type of atoms on each side of the equation
Explanation:
A pex
which bond shown are triple bonds
Answer:
Hey mate.....
Explanation:
This is ur answer.....
A triple bond is made of two pi bonds and one sigma bond. Examples of compounds with triple bonds include nitrogen gas, the cyanide ion, acetylene and carbon monoxide.
Hope it helps!
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Claim-Evidence-Reasoning
Question: Does the diagramed chemical equation above obey the Law of
Conservation of Matter?
Answer:
matter cannot be created or destroyed in chemical reactions. This is the law of conservation of mass. In every chemical reaction, the same mass of matter must end up in the products as started in the reactants. Balanced chemical equations show that mass is conserved in chemical reactions.
Explanation:
What does it mean when the
frequency of a wave increases?
A. the amplitude increases
B. the amplitude decreases
C the wavelength becomes shorter
D. the wavelength becomes longer
Answer:
The answer is C
Can you put a brainliest for me
Explanation:
Answer:
the wavelength becomes shorter
Explanation:
frequency increases, the wavelength gets shorter. As the frequency decreases, the wavelength gets longer.
rank the crystal lattice structures in order of decreasing efficiency of space in the structure.
Rank the crystal lattice structures in order of decreasing efficiency of space in the structure.
1. Simple cubic
2. Body centered cubic
3. Face centered cubic
4. Hexegonal close packed
perform the converters
a) 32gr C2H4-in liters
b) 7,5 litera N2- in molecules
c) 1.4•10 ² ³ molecules CH4- in atoms
Answer:
the answers are given in the photo
Boron and antimony are good elements to use as
Answer: Semiconductors
Explanation:
what is a “ medium” in regards to waves ?
why is it dangerous to wear contact lenses in the lab
Answer:
It is strongly recommended that students do NOT wear contacts lenses in the laboratory. Chemical vapors may penetrate the contact lens material and cause the lens to adhere to one's eye, which could be detrimental to the eye. Goggles are not vapor tight and do not completely eliminate this absorption.
P 1. Elements X and Y react to form an ionic compound a formula XY. What could be the proton (atomic) numbers of X and Y?
X | Y
A | 3 | 8
B | 6 | 8
C | 8 | 16
D | 12 | 16
Answer:
the answer is C
Explanation:
This is because group6 elements are diatomic and when they are chemically combined their subscript 2 cancels out
the photo has the question; please help asap ! i’m giving brainliest—i also have more chemistry, honestly i’m about to post a whole bunch of questions
Answer:
The process is to divide the molecules by Avogadro's number (6.02 x 10^23) to get the moles. And since it's specified at STP (standard temperature and pressure) we know that the molar volume would be 22.4L. So we can just multiply the moles by the molar volume in order to get the volume of H2S.
(2.18 x 10^24) / (6.02 x 10^23) = 3.62 moles (rounded)
Now just multiply the moles by the molar volume of STP, 22.4.
3.62 x 22.4 = 81 Liters (rounded) of H2S
Which dosage form is a semisolid preparation that contains very small solid particles that are suspended in a liquid
A GEL is a semisolid preparation that contains very small solid particles that are suspended in a liquid. A gel always contains an agent (e.g., agarose) that provides stiffness to the preparation.
A gel is a semisolid preparation that contains a gelling agent which provides stiffness to the preparation.
The gelling agent can be, for example, agarose (this gelling agent is used to prepare gels in electrophoresis).
In an agarose gel, agarose molecules are organized into three-dimensional (3D) structures similar to pores, which allow the passage of DNA fragments during electrophoresis.
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When a magnesium is heated, it burns in air with a dazzling white flame to form a white powder .What it called?
Balanced Equation –
[tex]\purple{\bf{2Mg + O_2 = 2MgO}}[/tex]
Physical states –
Magnesium → Mg ( In Solid State) Oxygen → [tex]\sf{O_2}[/tex] ( Gaseous State) Magnesium Oxide → MgO ( In Solid State Or White powder)_______________________________________
It is magnesium Oxide MgO2