Answer:
True. An English scientist by the name of John Newlands tried to classify the elements in a unique manner. He first started by arranging all the elements in a ascending order according to their atomic weights.
Which equation describes a physical change? i. H2O(s) ⟶ H2O(l) ii. Na+(aq)+Cl−(aq) +Ag+(aq)+NO3−(aq) ⟶ AgCl(s)+Na+(aq)+NO3−(aq) iii. CH3OH(g)+O2(g) ⟶ CO2(g)+H2O(g) iv. 2H2O(l) ⟶ 2H2(g)+O2(g) v. H+(aq)+OH−(aq)⟶ H2O(l)
Answer:
The answer is "Option i"
Explanation:
In this question, only option (i) is correct, and others were wrong which can be defined as follows:
In option (ii):
[tex]Na^+\ (aq)+Cl^- \ (aq) +Ag^+ \ (aq)+NO_3^- \ (aq) \to AgCl\ (s)+Na^+ \ (aq)+NO_3^-\ (aq) \\\\[/tex]
It is the complete ionic equation.
In option (iii):
[tex]CH_3OH\ (g)+O_2\ (g) \to CO_2\ (g)+H_2O\ (g)[/tex]
It is the combustion reaction but a not balanced equation.
In option (iv):
[tex]2H_2O\ (l) \to 2H_2\ (g)+O_2\ (g)[/tex]
It is the decomposition equation.
In option (v):
[tex]H^+\ (aq) +OH^-\ (aq)\to H_2O\ (l)[/tex]
It is the complete ionic equation.
Why doesn’t the KHP concentration have to be exactly 0.100M? Explain using complete sentences.
Answer:
The answer is in the explanation.
Explanation:
The KHP is an acid used as standard in titrations to find concentration of bases as NaOH.
The reaction that explain this use is:
KHP + NaOH → KNaP + H2O
where 1 mole of KHP reacts per mole of NaOH
That means, at equivalence point of a titration in which titrant is NaOH, the moles of KHP = Moles of NaOH added
With the moles of KHP = Moles of NaOH and the volume used by titrant we can find the molar concentration of NaOH.
The moles of KHP are obtained from the volume and the concentration as follows:
Volume(L)*Concentration (Molarity,M) = moles of KHP
If the concentration is more or less than 0.100M, the moles will be higher or lower. For that reason, we need to know the concentration of KHP but is not necessary to be 0.100M.
why do we shake syrup medicines before drinking
Answer:
The label may instruct you to shake a liquid medicine before using so that the active ingredients are evenly distributed throughout it.
Explanation:
Answer:
maybe because if somehow the liquids get separated then shaking them up would mix them back to how they are suppose to be originally.
Explanation:
what is chemistry?????
Answer:
chemistry - the science that studies the properties of substances and natural fenomens .
...........
Answer:
The Basic definition of Chemistry is:-
Chemistry is the scientific study of the properties and behavior of matter. It is the natural science that covers the elements that make up matter to the compounds that is composed of atoms, molecules and ions.
Convert 48,987 minutes to years
using the method of dimensional analysis
Answer:
Explanation:
48000 minutes [ 1 hour / 60 min ] 1 day / 24 hours ] [365 days / year]
48000 * [ 1/(60 * 24 * 365)]
48000 * [1 / 525600]
There are 0.0930954years in 48000 minutes
Which of the following is true of science? (2 points)
It can be disproven by philosophy and religion.
It does not change after new evidence is discovered.
It is based on the personal opinions of scientists.
It is based on testable and replicable evidence.
Answer:
It is based on testable and replicable evidence.
PLZ HELP ME
Which of these is an example of an example factor which affects the earths climate?
A - Decrease in the suns energy.
B - Warm and cold ocean currents.
C - Increase in atmospheric dioxide.
D - Release of dust during volcanic eruption
Answer:
D- Release of dust during volcanic eruption
Explanation:
During major explosive eruptions huge amounts of volcanic gas, aerosol droplets, and ash are injected into the stratosphere. Injected ash falls rapidly from the stratosphere -- most of it is removed within several days to weeks -- and has little impact on climate change. But volcanic gases like sulfur dioxide can cause global cooling, while volcanic carbon dioxide, a greenhouse gas, has the potential to promote global warming.
answer:
a - decrease in the suns energy.
explanation:
although the other options do discuss climate, temperature, etc., the sun DIRECTLY influences the earth's climate and would most likely affect it on a larger scale. for example, warm and cold ocean currents would affect the temperature of the ocean and could touch bay cities or islands, but they would not dictate the overall climate of the earth :)
♡ hopefully my reply helped you come to an answer~ please keep in mind that my response is purely that... MY response! i still have lots to learn, so please correct/educate me if you have found otherwise ♡
Which kind of bond would occur between sodium (Na, Group IA) and chlorine (Cl, Group VIIA)?
Answer:
ionic
Explanation:
I'll put the rest if the answers in comments
Answer:
1. Metallic bonds are responsible for many properties of metals, such as conductivity. Why is this possible?
*The bonds can shift because valence electrons are held loosely and move freely.*
2. Between which types of elements do ionic bonds occur, and how do electrons act within the bond?
*metals and nonmetals, electrons transferred*
3. Which kind of bond would occur between sodium (Na, Group IA) and chlorine (Cl, Group VIIA)?
*ionic*
4. Which type of bond and how many bonds would occur as carbon dioxide (CO2) is formed from carbon in Group IVA and oxygen in Group VIA?
*four covalent bonds*
5. How many covalent bonds is nitrogen (Group 5A) likely to form?
*three*
These are all the answers to the Bonds Quick Check.
Noble gases are the least reactive elements on the periodic table.
A. True
B. False
Answer:
The statement is True!"Why?"The Noble Gases have eight valence electrons, which fill their outer energy level. This is the most stable arrangement of electrons, so noble gases rarely react with other elements and form compounds.
Hope this helps!
why does an endothermic reaction require a greater activation energy than an exothermic one?
Answer:
in most of the endothermic reactions the atoms gains electrons from one to another. since the atom gains electrons there is a electron repulsive force between the host and the guest electron . As stability is inversely proportional to electron repulsive force the atom gains energy to attain stability .
The endothermic reaction mostly come under electron affinity
Explanation:
hope this helps you
if I am wrong just correct me
Please help I have been stuck on this problem for a couple hours and can't figure it out
Answer:
11.92 Liters O₂(g) at STP
Explanation:
For most stoichiometry problems, if one will convert all given data into moles, solve by rxn ratios, then finish by converting to needed dimensions to complete problem.
2Pb(NO₃)₂ => 2PbO + 4NO₂ + O₂
Given 237.5 grams PbO formed in reaction = 237.5 g/223.2 g/mole = 1.064 mole PbO
From equation ratios, moles O₂ formed = 1/2(moles PbO) = 1/2(1.064 moles O₂) = 0.532 mole O₂
0.532 mole O₂ = 0.532 mole x 22.4 liters/mole at STP = 11.91756272 liters (calculator answer) ≅ 11.92 liters O₂ at STP (4 sig.figs. based on given 237.5g PbO)
What is the correct equilibrium constant expression for the following reaction?
2NCl3(g) Û N2g) + 3Cl2g
Answer:
K = [N2] [Cl2]³ / [NCl3]²
Explanation:
The equilibrium expression, K, of a reaction:
aA + bB ⇄ cC + dD
Is defined as the ratio between the multiplication of concentrations of products powered to its reaction coefficient and the multiplication of concentrations of reactants powered to its reaction coefficient as follows:
K = [C]^c[D]^d / [A]^a[B]^b
Now, for the reaciton:
2NCl3 ⇄ N2(g) + 3Cl2(g)
K is:
K = [N2] [Cl2]³ / [NCl3]²
Which of the following molecules contains six bonding electrons?
A C2H4
B CO2
C H2S
D NCl3
Answer:
c2h4 (etthane........
bexcuse it has 6 bond of hydrogen
C₂H₄ molecules contains six bonding electrons. Therefore, option A is correct.
What do you mean by the term bonding ?Chemical bonding is the process through which two or more atoms, molecules, or ions establish a chemical link to create a chemical compound. The atoms in the resultant molecule are held together by these chemical bonds.
Chemical bonds have three basic characteristics that must be taken into account: their strength, length, and polarity. The distribution of electrical charge among the atoms connected by a bond determines its polarity.
C₂H₄ molecules has six bonding electrons. This molecule is called as Ethylene. When bonding is done between two atoms, each atom shares a pair of electrons with each other.
Hence, for every one bond, two electrons are shared between two atoms
Thus, option A is correct.
To learn more about the bonding, follow the link;
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How many pounds of force is 240 Newtons?
Answer:
53.9541 pound force...
what is a cubic unit cell ?
cubic unit cell is the smallest repeated unit which have all angles equal to 90 and all have edge lengths equal
It is the type of the Unit cell which is having all angles equal to 90 and all sides equal to each other
it's is a unit cell with cubic structure
2. School bus accidents are very rare, possibly because they are so easy to see.
School buses have been around since 1915, but the official color of bright
yellow wasn't used until 1939. Would grey school buses get in more accidents?
Help plz!!!
Answer:
Grey school buses would likely get in more accidents because other drivers are expecting a yellow bus to make frequent stops and the lights and stop sign are noticeable on a brighter color.
Explanation:
yellow buses are easier to see in fog than a grey bus
which orbital has the lowest energy
Answer:
s orbital
Explanation:
it has the lowest energy because
Paulis law state that orbitals with lower energy must be fill first before that of higher energy
and the s orbital is filled first
potassium permanganate + water = ? which product will they form,and in which phase is it?
KMnO4 + H2O = MnO2 + O2 + KOH
Must click thanks and mark brainliest
The boiling point of water is 100ºC. The boiling point of acetone is 56ºC. Which statement about distilling a mixture of acetone and water is correct?
Acetone remains in the original container.
Water will vaporize from the mixture before acetone.
Acetone is captured and cooled.
Water is collected as it leaves the mixture.
Answer:
Acetone is captured and cooled.
Explanation:
The boiling point of acetone is lower than that of water, so it will vaporise before water. Then acetone will be captured and cooled to separate it from its mixture with water.
The statement which is correct about distilling a mixture of acetone and water is as follows:
Acetone is captured and cooled.Thus, the correct option is C.
What is Distillation?Distillation may be defined as a procedure that generally involves the conversion of a liquid into a vapor that is eventually condensed back to liquid form. With the help of this process, the separation of components or substances from a liquid mixture by using selective boiling and condensation occurs.
Acetone has the lowest boiling point as compared to water. So, it boils faster than that water and vaporizes before water. After the termination of this process, the acetone will be predominantly captured and cooled to separate it from its mixture with water.
Therefore, the correct option for this question is C.
To learn more about the Boiling point of acetone, refer to the link:
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Which atom would be neutral?
1an oxygen atom with 16 electrons, 18 protons, and 16 neutrons
2an oxygen atom with 4 electrons, 6 protons, and 4 neutrons
3an oxygen atom with 9 electrons, 8 protons, and 8 neutron
4an oxygen atom with 8 electrons, 8 protons, and 9 neutrons
Answer:
an oxygen atom with 8 electrons, 8 protons, and 9 neutrons
Explanation:
A proton has a positive charge and an electron has a negative charge. Magnitude of both of these charges is same. So, we need the same number of electrons and protons to make the atom neutral.
Neutron is neutral, so we can safely ignore it in this question.
Answer:
an oxygen atom with 8 electrons, 8 protons, and 9 neutrons
Explanation:
Products formed when chlorine is produced by the electrolysis of concentrated sodium chloride solution
The products formed during electrolysis of concentrated sodium chloride solution are SODIUM HYDROXIDE and HYDROGEN GAS.
ELECTROLYSIS is the process by which electrolytes allows electric current to pass through it and is decomposed on the process.
CHLORINE is an element which can be produced industrially through the process of electrolysis of brine (concentrated sodium chloride solution). When sodium chloride is dissolved in water, it's ions separate and are capable of conducting electricity.
The products formed during this process includes:
chlorine sodium hydroxide and hydrogen gas.CHLORINE: this is released at the positive electrode during electrolysis. It is used for the following purposes:
it is used for sterilisation of water for domestic and industrial use it is used as a bleaching agent for cotton, linen and wood-pulp.SODIUM HYDROXIDE: this remains in the solution during electrolysis. It is used for the following:
processing food products, removing pollutants from water and manufacture of paper.HYDROGEN GAS:this is released at the negative electrode during electrolysis. this is used for the following:
manufacture of ammonia, hydrochloric acid and methanol it serves as constituents of many gaseous fuels such as water gas and coal gasTherefore other products during electrolysis of concentrated sodium chloride solution are SODIUM HYDROXIDE and HYDROGEN GAS.
learn more here:
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what are the 2 main methods of combination of elements??
Answer:
to make them react to each other to form a compound
Explanation:
mark me as brainliest pls
Answer:
An element is a material that consists of a single type of atom. Each atom type contains the same number of protons. Chemical bonds link elements together to form more complex molecules called compounds. A compound consists of two or more types of elements held together by covalent or ionic bonds.
Show the comparative structure of union Parishad and Pourahava in chart.
Answer:
how will I show?
Explanation:
pLS teacher me
What type of reaction is shown below:
Ethanoic acid + propanol -> propyl ethanoate + water
A. Polymerization
B. Addition (water)
C. Elimination
D. Esterification
Answer:
c
Explanation:
because mix with propanol
Which of the following pairs lists a substance that can neutralize HNO3 and the salt that would be produced from the reaction?
O BaOH2 and Ba(NO3)3
O KOH and K2NO3
O NH3 and NH4NO3
O NH4 and NHA(NO3)2
Answer:
NH3 and NH4NO3
Explanation:
I took the test and guessed this since I couldn't find it here, it turned out to be correct so I thought I'd share.
The substances that can react with HNO3 to neutralize it are NH3 and NH4NO3.
What is neutralization?The term neutralization has to do with the reaction between an acid and a base to yiled salt and water only.
The substances that can react with HNO3 must be basic substances hence the substances required are NH3 and NH4NO3.
Learn more about neutralization reaction:https://brainly.com/question/20038776
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Please help with the Volume one
Answer:
im a just achild
Explanation:
Answer:
c
Explanation:
0.5dm³
follow me if you want
If ya could change somethin bout ya previous science classes what would it be?
If I could change something in my previous science classes, it would have been the fact that I struggled in the question concerning exponents. It was simple one, but I don't know how I didn't understood that. For example, if there is a question with a calculation "xy²", then I would first multiply x and y, and then calculate the exponent. I did 3 of the questions wrong because of this, it was when I was in 7th grade. I wish I had not done this kind of silly mistake. I an in 10th grade and understand it well now, though.
Describe how to make a buffer solution using a strong base and one other reagent. 15 POINTSSSSSSSS
Answer:
Hi! hopefully this helps you
Explanation:
You can make a buffer solution for a specific pH (potential of hydrogen) by mixing together a weak acid like acetic acid HC2H3O2 with a salt that contains the conjugate base like sodium acetate NaC2H3O2. A neutralization reaction would occur as you are mixing a weak acid and a strong base.
When you add the base to an acidic solution, the solution becomes less acidic and moves toward the middle of the pH scale. Aka neutralization
Hope this helps! best of luck <3
Which of the following substances can be used to neutralize HF? Question 6 options: A) NaOH B) HF C) HCl D) SO2
Answer:
A) NaOH
got it right on the test.
Explanation:
Answer:
NaOH
Explanation:
help me please I will mark as brainliest for the first correct answer
Answer:
1. 3-methylpentane
2. 2-bromo-3-chloropentane
3. 2,2,4-trimethylpentane
Explanation:
1. CH3CH2CH(CH3)CH2CH3.
Methyl group is in the third carbon atom in the long chain. The organic compound has five(5) carbon atoms thus it is named as pentane.
Therefore the name of the compound is
3-methylpentane
2. CH3CH(Br)CH(Cl)CH2CH3
The compound has Chlorine and Bromine in the carbon chain. Chlorine is given as chloro-, Bromine is given as bromo, depending on the position in the carbon chain. Bromine is located in 2 carbon atom and chlorine is in third(3) carbon atom in the long chain. The long chain has five carbon atoms thus pentane.
Naming of the compound we begin with the on lowest in the alphabet. The name of the organic compound is therefore;
2-bromo-3-chloropentane
3. CH3CH(CH3)3CH(CH3)CH2CH3
In this long chained organic compound, methyl-group is found in 2,2 and 4th positions. Since this is still pentane, naming the organic compounds, we start with the one with the lowest carbon. Therefore this becomes;
2,2,4-trimethylpentane
I hope this helps you to know how to name the organic compounds.
