0.152 moles
Given that:The mass of the oxygen gas produced = 4.87 g
Also, The molar mass of oxygen gas, = = 32 g/mol
The formula for the calculation of moles is shown below:
moles = [tex]\frac{Mass-taken}{Molar-mass}[/tex] *
Thus,
moles = [tex]\frac{4.87g}{32g/mol }[/tex]
Both given values and the answer is in 3 significant digits.
brainlist pls?
*i put a dash between mass and taken as formulas do no spaces
how many moles of oxygen atoms are present in 0.4 moles of oxygen gas
Answer:
Each molecule of O2 is made up of 2 oxygen atoms. So 1 mole of O2 molecules is made up of 2 moles of oxygen atoms. Therefore 1 mole of oxygen gas contains 2 moles of oxygen atoms. And 0.4 moles of oxygen gas contains 0.8 moles of oxygen atoms.
There are 0.8 moles of oxygen atoms in 0.4 moles of oxygen gas.
Oxygen gas (O₂) consists of two oxygen atoms bonded together. Therefore, to determine the number of moles of oxygen atoms present in a given amount of oxygen gas, we can simply multiply the number of moles of oxygen gas by the number of oxygen atoms per molecule, which is 2.
Given that we have 0.4 moles of oxygen gas, we can calculate the number of moles of oxygen atoms as follows:
Number of moles of oxygen atoms = Number of moles of oxygen gas × Number of oxygen atoms per molecule
= 0.4 moles × 2
= 0.8 moles
Therefore, there are 0.8 moles of oxygen atoms present in 0.4 moles of oxygen gas.
This calculation is based on the stoichiometry of oxygen gas, which indicates that each molecule of O₂ contains two oxygen atoms. By considering the mole ratio between oxygen gas and oxygen atoms, we can determine the number of moles of oxygen atoms in a given quantity of oxygen gas.
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Which method of separation would be most appropriate for separating a mixture of water and alcohol?
A. evaporation
B. chromatography
C. distillation
D. filtration
Answer:C. distillation
Explanation:
Compounds having different boiling points when mixed can be separated by Fractional distillation.
Now when there is a mixture of water and alcohol, Upon heat, we would see that the alcohol will boil at a lower temperature than water for eg, ethanol will boil at 78.5 degrees Celsius, vaporizes and distills into the fractionating columns leaving the water which we know boils at 100 degrees Celsius.
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0. When measuring tert-butyl alcohol for this experiment, a student first weighs an empty graduated cylinder, then pours 15 mL of the alcohol into the graduated cylinder and weighs the cylinder again. He records the amount of alcohol used as the difference in these two masses. What is wrong with this method
Answer:
Both have solutions in the graduated cylinder.
Explanation:
Recording the amount of alcohol used as the difference between two masses is the wrong method used for measuring tert-butyl alcohol for the experiment. For measuring tert-butyl alcohol for this experiment, the student has to measure the two masses when both the graduated cylinders has solution of tert-butyl alcohol not when one of it is empty (having no tert-butyl alcohol ).
The wrong aspect is that the liquid didn't need to be weighed. Instead the volume should have been recorded with the aid of the graduated cylinder.
What is a Graduated cylinder?This is a cylinder with marked readings and is used to measure the volume of liquids in the laboratory.
The graduated cylinder will accurately measure the amount of alcohol used due to it being volatile and the mass fluctuating during the measurement.
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Which chemical can remove color of red/Pink phenol and make it clear like water transparent?
How many grams of Al were reacted with excess HCl if 3.86 L of hydrogen gas were collected at STP in the following reaction?
2 Al (s) + 6 HCl (aq) → 2 AlCl₃ (aq) + 3 H₂ (g)
The amount, in grams, of Al that reacted with excess HCl if 3.86 L of hydrogen gas were collected at STP in the reaction would be 3.099 grams.
Stoichiometric problemFrom the equation of the reaction, the mole ratio of Al that reacts with that of hydrogen gas that forms is 2:3.
At STP, 1 mole of any gas is equivalent to 22.4 Liters of the gas.
But only 3.86 L of hydrogen was formed in the reaction.
The equivalent mole of 3.86 L hydrogen at STP would be:
3.86 x 1/22.4 = 0.1723 moles
From the mole ratio, the equivalent mole of Al that will produce 0.1723 moles of hydrogen gas would be:
0.1723 x 2/3 = 0.1149 moles
Recall that: mass = mole x molar mass
Mass of 0.1149 moles Al = 0.1149 x 26.98
= 3.099 grams
Thus, the amount of Al that reacted with excess HCl is 3.099 grams.
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1.46 mol sample of nitrogen gas at a temperature of 14.0 °C is found to occupy a volume of 23.7 liters. The pressure of this gas sample is mm Hg
Explanation:
Since there are no gas constant with the unit of mmHg, you just have to use the gas constant for atm, and then convert that into mmHg
Give 3 examples of chemical change and physical change in daily life
Explanation:
Physical change
★ Boiling of water
❤︎ freezing of water
❣︎ washing of clothes
♫︎ mixing black and brown stones
Chemical change
➪ making of dough
㋛︎ burning of wood
❥︎ cooking of the raw food
❁ burning of paper
ꨄ︎ rusting of iron
★★★➪➪➪➪ it was help to you
Deduce the formula of calcium Phosphide.
Answer:
[tex]{ \sf{Ca _{3} P_{2} }}[/tex]
Calculate [H3O+] for pH 1.86. Steps please.
Answer:
[H₃O⁺] = [H⁺] = 10^-pH = 10⁻¹°⁸⁶ = 0.0138M in [H⁺]
Explanation:
By definition pH = -log[H⁺] => [H⁺] = 10^-pH = 10⁻¹°⁸⁶ = 0.0138M in [H⁺]
Using your calculator ... I am using a TI-30XA scientific calculator.
=> start by entering the number 1.86 => then press the (+/-) function => this will insert a negative symbol => -1.86,=> next find button with "2nd" printed on face (on some calculators the button is in yellow); press this button to change to 'secondary mode',=> find the symbol (10ˣ) ... the button below this symbol is usually the 'log' button, then press it => the answer of interest will show in the display window. => ...Depending on the calculator, the answer may show as 0.0138, or 1.38x10⁻², or 1.38E-2 (=1.38 x 10⁻²). It is the user's job to insert dimensional units into answer of interest => 0.0138M, or 1.38 x 10⁻²M, or 1.38E-2M.
1.38E-2 which is 1.38 x 10⁻².
Calculate the percent error in the atomic weight if the mass of a Zn electrode increased by 0.3681g and 6.514x10-3 moles of Zn was produced. You may assume the molar mass of elemental zinc is 65.38 g/mol.
a. -13.5%
b. 13.52%
c. -13.52%
d. 13.5%
Answer:
13.5%
Explanation:
To answer this you need to understand that percentage error can never be negative as we use absolute value in the equation
To get molar/atomic mass = mass/moles
=0.3681g/(6.514×10^-3)moles
=56.509g/moles
percentage error = (65.38-56.509)/65.38 ×100
=13.56% (this is what I'm getting without rounding off your question wasn't specific on how many d.p to use)
A metal (C = 0.2158 cal/g· °C) is removed from a hot (350. °F) oven in which it had achieved thermal equilibrium. The metal is placed into 200. mL acetic acid. The temperature of the acid increases to 90.3 °C from 24.3 °C. What is the mass of the metal? (dacetic acid = 1.04 g/cm3; Cs, acetic acid = 2.055 J/g·°C) Group of answer choices 120. g 362 g 1452 g 347 g 281 g
Answer:
362g
Explanation:
heat lost by metal= heat gained by acetic acid
tfs are the same so you cando delta T
convert Cal/gc to J/gc
thectgod ig follow
Suppose you are using distillation to separate cyclohexane and toluene. The boiling point of cyclohexane is Choose... oC and the boiling point of toluene is Choose... oC. Therefore, the liquid collected first should be Choose... .
Answer:
81°C
111°C
cyclohexane
Explanation:
Distillation is a process of separating two liquids based on differences in Bolling point. For two substances having different boiling points, they are collected as they are converted into vapour, condensed and move down the condenser one after the other.
Since the boiling point of cyclohexane is less than that of toluene, cyclohexane is collected first before toluene.
How many nitrate ions are present in the following aqueous solution?
5.08 L of a solution containing 2.68 x 1021 formula units of lithium nitrate per liter.
When you have the number, determine its log (base 10) and enter that value with 3 decimal places
Answer:
22.1
Explanation:
Step 1: Calculate the number of formula units of lithium nitrate
A 5.08 L solution contains 2.68 × 10²¹ formula units per liter.
5.08 L × 2.68 × 10²¹ formula units/1 L = 1.36 × 10²² formula units
Step 2: Calculate the number of nitrate ions
Lithium nitrate dissociates completely in water according to the following equation.
LiNO₃(aq) ⇒ Li⁺(aq) + NO₃⁻(aq)
The molar ratio of LiNO₃ to NO₃⁻ is 1:1. The number of nitrate ions is 1/1 × 1.36 × 10²² = 1.36 × 10²².
Then,
log (1.36 × 10²²) = 22.1
The number of nitrate ions are present in the following aqueous solution is 13.6x10²¹, and log(base 10) value of this is 22.2.
What are strong electrolytes?
Those salts which are completely dissociate into their ions in the solution form will known as strong electrolyte.
Lithium nitrate is a strong electrolyte and it shows complete dissociation as:
LiNO₃ → Li⁺ + NO₃⁻
Given that,
1 liter of solution containing = 2.68 x 10²¹ formula unit
5.08 L of solution containing = 5.08 x 2.68 x 10²¹ = 13.6x10²¹ formula unit
So, number of nitrate ion in given solution = 13.6x10²¹ formula unit
Log(13.6x10²¹) = 22.1
Hence, required values are 13.6x10²¹ and 22.1.
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How are radioactive isotopes used to diagnose thyroid problems?
Answers
A.
Production of radioactive iodine by the thyroid is measured.
B.
Uptake of radioactive iodine by the thyroid gland is measured.
C.
Destruction of damaged cells by radioisotopes is measured.
D.
Absorption of gamma rays from ingested radioisotopes is measured.
Question
Answer:
A
Explanation:
uptakw of raduoactive iofine by the thyroid gland js measurd
explain chlorination of methane
Answer:
Methane and chlorine
If a mixture of methane and chlorine is exposed to a flame, it explodes - producing carbon and hydrogen chloride. This is not a very useful reaction! The reaction we are going to explore is a more gentle one between methane and chlorine in the presence of ultraviolet light - typically sunlight. This is a good example of a photochemical reaction - a reaction brought about by light.
CH4+Cl2+energy→CH3Cl+HCl(3.4.2)
The organic product is chloromethane. One of the hydrogen atoms in the methane has been replaced by a chlorine atom, so this is a substitution reaction. However, the reaction doesn't stop there, and all the hydrogens in the methane can in turn be replaced by chlorine atoms.
Substitution reactions happen in which hydrogen atoms in the methane are replaced one at a time by chlorine atoms. You end up with a mixture of chloromethane, dichloromethane, trichloromethane and tetrachloromethane.
I hope this help you!:)
Explanation:
Determine the rate of reaction based on the data below:
75-
rate of reaction = y
hydrogen produced (cm)
х
y
25
50
75
100
125
time (seconds)
Answer:
75
Explanation:
is the answer for your question
Which of the following chemical equations depicts a balanced ionic equation?
A. 2OH−+Ca2+−>Ca(OH)2
B. OH−+Ca2+−>Ca(OH)2
C. 2OH−+Ca2+−>2Ca(OH)2
D. OH−+2Ca2+−>Ca(OH)2
Answer:
[tex]{ \sf{A. \: 2OH {}^{ - } _{(aq)} +Ca {}^{2 + } _{(aq)} −>Ca(OH) _{2(s)} }}[/tex]
The chemical equations depict a balanced ionic equation is 2OH−+Ca2+−>Ca(OH)2. option A is correct.
What is the ionic equation?
An ionic equation is a chemical equation in which the electrolytes in an aqueous solution are expressed as dissociated ions. The ions in aqueous solutions are stabilized by ion-dipole interactions with water molecules
Strong acids, strong bases, and soluble ionic compounds (usual salts) exist as dissociated ions in an aqueous solution, and Weak acids and bases and insoluble salts are usually written using their molecular formulas because only a small amount of them dissociates into ions.
Ag+(aq) + NO3-(aq) + Na+(aq) + Cl-(aq) → AgCl(s) + Na+(aq) + NO3-(aq) is an ionic equation example.
Therefore, the balanced ionic reaction will be 2OH−+Ca2+−>Ca(OH)2. option A is correct.
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Why benzene is called aromatic compound according to Huckel’s rule?
Answer:
It obeys rule
Explanation:
Benzene is an aromatic hydrocarbon because it obeys Hückel's rule.
Answer:
Benzene is an aromatic compound because it is planar, cyclic, conjugated and has (4n +2) π electrons, where n= 1.
Explanation:
Hückel's rule states that a molecule is aromatic if it is planar, cyclic, conjugated and has (4n +2) π electrons.
Breaking it down into 4 requirements, we have:
planarcyclicconjugated(4n +2) π electronsLet's look at each of the 4 parts!
What is planar?
Planar refers to the molecule being flat. When an atom is sp² hybridized, it is in a trigonal planar geometry. Let's look at the benzene molecule. Each carbon is attached to 3 other atoms, namely 2 carbons and 1 hydrogen. This means that each carbon is sp² hybridized, making the molecule planar.
Cyclic
This refers to the molecule having a closed ring shape. Benzene fulfils this criteria.
Conjugation
This refers to a system of connected p orbitals, which allows π electrons to delocalize. Each carbon atom in benzene has one 2p orbital, making benzene a conjugated molecule. For molecules that are not cations or anions, conjugated molecules are those that have alternating single and double bonds.
(4n +2) π electrons
n is an integer (e.g. 0, 1, 2, 3) thus for the molecule to be aromatic, it can have 2, 6 or 10 π electrons (non exhaustive). This separates an aromatic compound from an antiaromatic compound, which has 4n π electrons instead.
Benzene has 6 π electrons, so n has a value of 1 in this case.
Thus, benzene is an aromatic compound because it is planar, cyclic, conjugated and has (4n +2) π electrons.
_______
Counting the number of π electrons
Let's look at π bonds!
A double bond is made up of 1 σ bond and 1 π bond, and each π bond is made up of 2 π electrons. We do not count the number of single bonds since single bonds are made up of 1 σ bond only.
There are 3 double bonds in the Kekulé structure of benzene. Thus, the number of π electrons in benzene is 3(2)= 6.
Attached diagrams
Kekulé structure of benzenesp² hybridized carbon6 p orbitals in benzene ringA strawberry nutritional drink used for a liquid diet is flavored with methyl butanoate. Draw the structure of methyl butanoate.
Answer:
See explanation and image attached
Explanation:
Methyl butanoate is an ester. Esters have the general molecular formula, RCOOR where the two Rs may represent the same or different alkyl groups.
Methyl butanoate is has a fruity odor, smelling like apples or pineapples fragrance. It is also called methyl butyrate.
The structure of the compound is shown in the image attached to this answer.
Prepare a flow sheet for the preparation of triphenylmethanol. Using your knowledge of the physical properties of the solvents, reactants, and products, show how the products can be purified. Indicate which layer should contain the product in the liquid/liquid extraction steps.
Answer:
See explanation and Image attached
Explanation:
The preparation of triphenylmethanol occurs as shown in the image attached to this answer.
The first step is the nucleophillic reaction of the phenyl magnesium bromide with the carbonyl group.
Reaction of the second molecule of phenyl magnesium bromide with the product yields triphenyl methoxide ion. Reaction with acid yields the triphenylmethanol product which is extracted into the organic phase.
The triphenylmethanol product can be purified by recrystallization.
why is it difficult to undergo nucleophilic substitution in haloarene?
Answer:
In Haloarenes the C atom to which the X group is attached is SP2 hybridized thus it is become difficult to replace it by the Nucleophile. Since arenes and Vinyl halides are electron rich molecules due to presenceof n bonds, they repel Nucleophile attacking them.
Question:-
Why it is difficult for haloarenes to undergo nucleoplhilic subsituⁿ reaction?
Answer:-
Haloarenes are less reactive towards the nucleoplhilic substitution rxⁿ . This is due to following reasons :-
[tex]\red{\bigstar}\underline{\textsf{ Reason 1 :- Partial double bond character .}}[/tex]
Halogen atom has one lone pair, and due to presence of π - σ - lp , resonance is established in the compound ( see attachment) . Due to resonance there is a partial double bond character in the carbon halogen bond , so it is difficult to break a double bond than a single bond.
[tex]\rule{200}2[/tex]
[tex]\red{\bigstar}\underline{\textsf{ Reason 2 :- $\pi$ cloud .}}[/tex]
When a nucleoplhile comes to attack , it is repelled by the π-cloud of the benzene ring.
[tex]\rule{200}2[/tex]
[tex]\red{\bigstar}\underline{\textsf{ Reason 3 :- Phenyl cation .}}[/tex]
If somehow the halogen atoms leaves the benzene ring ,being more electronegative than carbon , it takes away the electron , thus a positive charge is left on benzene ring and the phenyl cation so formed is very unstable .
[tex]\rule{200}2[/tex]
Assume you have 4 solids (A, B, C and D) of similar mass. Which of these requires the greatest energy input to melt?
polar covalent
covalent network
ionic compound
nonpolar covalent
The solid that require the greatest energy input to melt by mass is the option;
Covalent network
Reason for the above answer is as follows;
The elementary particles of a solid are held together by bonds that require
an input of energy to unlock, and once broken, the particles are then able
to change location within their containing vessels with less restrictions
Types of bonds
Polar covalent molecular solids have the following characteristics;a) Soluble in water b) Low melting point, b) Conduct electricity
Solids that are made up of a covalent network have the following characteristicsa) High melting point temperature b) Non conductive of electricity c) Not soluble in water
Solids of ionic compounds have the following characteristics;a) High melting point temperature b) The liquid state and solution
conducts electricity c) Soluble in water
Solids that have nonpolar covalent bonds have;a) Low melting point b) Normally in the gaseous or liquid state b) Not water soluble
Therefore, the covalent network, and the solids ionic compounds require the most energy to melt, however, the strength of the ionic bond in an ionic compound is a factor the charges present and the sizes of the atom, while
the covalent network solid, are combined to form essentially as a single
molecule and therefore require the greatest heat energy input break the bonds of the molecule down in order to melt
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Help ASAP 15 Points
A student is conducting their science experiment on the effect of caffeine on dogs. He has 3 groups of test subjects. The 1st group of dogs receives plain water. The 2nd group of dogs receives 10 mg of caffeine each, and the 3rd group receives 50 mg of caffeine each. He will measure their activity levels by recording how long each dog runs without stopping, after giving them the pills. What could be evaluated in this experiment to ensure reliability?
A. The different amounts of caffeine given could lead to different activity levels which would throw off the result of the experiment.
B. The group that receives water will be an outlier and throw off the best fit line.
C. The test subjects are dogs and not people, so their data is unreliable.
D. If the dogs are different breeds, their activity levels could be different because of their breed and not the caffeine. Reset Selection
Answer:
The independent variable of an experiment is the one that is intentionally changed or manipulated to see the results of changing said variable.
We are told that in each different group, the amount of caffeine that is given to the dog's changes - in the control group, they get no caffeine, in the 2nd group, they get 10 mg of caffeine each, and in the 3rd group, they get 50 mg of caffeine each.
Therefore, since the amount of caffeine that is given to the dogs is the only variable that is being manipulated, this is the independent variable.
Answer: The independent variable of an experiment is the one that is intentionally changed or manipulated to see the results of changing said variable.
The independent variable of an experiment is the one that is intentionally changed or manipulated to see the results of changing said variable.
We are told that in each different group, the amount of caffeine that is given to the dog's changes - in the control group, they get no caffeine, in the 2nd group, they get 10 mg of caffeine each, and in the 3rd group, they get 50 mg of caffeine each.
Therefore, since the amount of caffeine that is given to the dogs is the only variable that is being manipulated, this is the independent variable.
We are told that in each different group, the amount of caffeine that is given to the dog's changes - in the control group, they get no caffeine, in the 2nd group, they get 10 mg of caffeine each, and in the 3rd group, they get 50 mg of caffeine each.
Therefore, since the amount of caffeine that is given to the dogs is the only variable that is being manipulated, this is the independent variable.
Explanation:
Which processes occur during the second stage of technological design? Check all that apply.
designing a solution
studying relevant information
rebuilding and retesting
reporting a solution
defining criteria of success
identifying a problem
building a prototype
What happens to the electropositive character of elements on moving from left to right along a period in a periodic table?
Answer:
On moving from left to right in a period the electropositive character decreases as the tendency to lose electrons decreases.
Explanation:
Complete (predict the products, write correct formulas) and balance the following reaction:
Gaseous hydrochloric acid reacts with solid calcium hydroxide. Include states of matter and use subscripts as needed to receive full credit for a correct answer.
Explanation:
since hydrochloric acid is an acid and calcium hydroxide is a base, we know that this is an acid base reaction. The ions will then dissociatiate and bond with one another.
Aspirin that has been stored for a long time may give a vinegar like odour and give a purple colour with FeCl3. What reaction would cause this to happen
?.
Answer:
See explanation
Explanation:
The IUPAC name of aspirin is 2-Acetoxybenzoic acid. It is composed of an acetoxy moiety and a benzoic acid moiety.
The compound can be hydrolysed under prolonged storage conditions to yield acetic acid which causes the vinegar like odour.
Also, one of the products of this hydrolysis bears a phenol group which reacts with FeCl3 to give a purple color.
Please guys please answer this
Answer:
1. Because the rules will keep you safe it prevents you from getting hurt.
2.i) don't taste chemical
ii) Always wear protective gears
iii) be careful with tool
iv) wear protective gloves
Explanation:
help everyone get out quickly
An alkane can show structural isomerism if it has at least ______ carbon atom
1)1
2)2
3)3
4)4
Spam = report and kick u
Answer:
2) 3 carbons
Explanation:
The alkane with one carbon is methane but it has no isomer.
The alkanes starting with propane only have isomers
Explanation:
An alkane can show structural isomerism if it has at least __4__ carbon atom
Identify the conjugate pairs in the following acid-base reaction
H₂CO₃(aq) + C₅H₅N(aq) HNO₃-(aq) + HC₅H₅N+(aq)
H2CO3 is an acid because it gave away a proton to become HNO3~.
HNO3~ is a conjugate Base because Acids become conjugate Bases after giving away a proton.
C5H5N is a base because it accepted the proton from H2CO3 to become HC5H5N+.
HC5H5N+ is a conjugate Acid because Bases become Conjugate Acids after accepting a proton.
