Energy change is the conversion of the energy stored in reactants to products. In the reaction between hydrogen and iodine, the energy change is -7 kJ/mol. Thus, option D is correct.
What is total energy change?Total energy change is the conversion of the energy from a substance to another when the reactant undergoes modification to produce a product.
The reaction is given as,
H₂ + I₂ → 2HI
In the reaction, the bonds between H-H and I-I are broken to release energy that produces two H-I bonds as the product.
Given,
H-H bond = 436 kJ/mol
I-I bond = 151 kJ/mol
H-I bond = 297 kJ/mol
So, 436 kJ/mol + 151 kJ/mol - 2x297 kJ/mol = -7 kJ/mol
Therefore, -7 kJ/mol is the total energy change in the reaction involving hydrogen and iodine.
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Which list of elements contains a metal, a metalloid,a nonmetal, and a noble gas
Answer:
sodium, silicon, and argon
Explanation:
castle learning
Which represents the greatest time frame in which a short-term environmental change can occur?
in days
O in minutes
O over hundreds of years
O over thousands of years
Answer:
in days
Explanation:
A short term environmental change refers to changes in the environment that happens within a short period of time, for example, flooding, drought, volcanic eruptions etc. In contrast to short term environmental change, long term environmental change takes place over a long period of time hence species have a longer time to adapt to it. Short term environmental changes may or may not be caused by humans. An example of a short term environmental change caused by humans is oil spillage. Short term environmental changes may lead to the the migration of species from the ecosystem.
Short term environmental changes usually occur within a very short time. The greatest time frame in which a short term environmental change can occur is in a matter of days. Only longterm environmental changes span hundreds and thousands of years.
Answer:
it is c
Explanation:
i took the test :)
Balance the reaction. A coefficient of "1" is understood. Choose option "blank" for the correct answer if the coefficient is "1." 2AgNO₃ + MgCl₂ 2AgCl + Mg(NO₃)₂
Answer:
The balanced equation is: 2AgNO₃ + MgCl₂ ------> 2AgCl + Mg(NO₃)₂
Explanation:
The law of conservation of mass states that in a normal chemical reaction, matter is neither created nor destroyed.
According to the law of conservation of mass, therefore, when a chemical reaction occurs, the mass of the products should be equal to the mass of the reactants. This implies that the amount of the atoms in each element in the chemical reaction remains the same before and after the reaction. A balanced chemical equation therefore, is one that shows that the number of the atoms involved in the reactants side is equal to the number of atoms in the products side.
Considering the given reaction:
2AgNO₃ + MgCl₂ ------> 2AgCl + Mg(NO₃)₂
The amount in moles of each atom in the reaction is as follows;
Ag = 2 moles of atom on each side
N = 2 moles of atoms on each side
O = 6 moles of atoms on each side
Mg = 1 mole of atoms on each side
Cl = 2 moles of atoms on each side
Therefore, the above chemical equation is balanced.
Answer:
The equation is already balanced.
Explanation:
What does the kinetic theory say about the kinetic energy present in solids
Answer: The kinetic energy of solids is limited to vibrational energies..the particles are tightly bound in their crystalline structure and can only bend, flex, and vibrate about relatively fixed position. When vibrational energies exceed the strength of the force holding the particles together, the crystal structure collapses and we say the material melted. The particles can now have, in addition to its vibrational energies, rotational energy. Chunks of the collapsed crystal can, like a ball floating in water, rotate without showing much translational energy. Generally, we associate solids with vibrational kinetic energy, liquids with rotational kinetic energy, and gases with translational kinetic energy. Actually though, liquids have both vibrational and rotational energies, and gases have all three.
Can the pH scale be utilized for all acids (Arrhenius, Bronsted-Lowry, and Lewis)? Give examples of substances from each definition category that can/cannot use the pH scale and explain your reasoning.
PLEASE ANSWER
Answer:
No
Explanation:
The pH scale is a scale graduated from 0-14 which shows the degree of acidity of alkalinity of a substance. The pH scale is graduated in such a way that 0-6.9 indicates acidity, 7.0 indicate a neutral substance, while a pH of 8-14 indicates alkalinity respectively.
There are three main definitions of acids/bases
- Arrhenius definition
-Brownstead-Lowry definition
-Lewis definition
Arrhenius explains acids as any substance that produces hydrogen ions as its only positive ion in solution while a base produces hydroxide ions as its only negative ion in solution. The pH scale is based on corresponding values of pH derived from aqueous solutions of these substances.
However, not all acids/bases produces hydrogen or hydroxide ions in solution. Brownstead-Lowry definition of acids and Lewis definition of acids could be extended to nonaqueous media where the pH can not be measured as there are no hydrogen or hydroxide ions present in the solution.
This implies that pH measurement may not apply to acids/bases in the all the categories of acids/bases hence it can not be utilized for all acids and bases.
Arrhenius - sodium carbonate
Brownstead-Lowry - concentrated HF
Lewis acid - AlCl3
Which statement is a scientific law?
A.Scientists use genes to explain why evolution happens.
B.Genes are long patterns that are similar to computer codes.
C.A person’s traits are controlled by different forms of a gene.
D.The discovery of genes changed how scientists think about life.
Answer:
A.Scientists use genes to explain why evolution happens.
Explanation:
:)
What is the definition of acid ?
WILL MARK BRAINLIEST (if the answer is good and hasn't been copied from google and the first one who answer the question )
Answer:
Acid is a compound which dissolves in water to produce hydrogen ions (H+) and described as proton donors.
Acetylene is the simplest hydrocarbon
that contains carbon-carbon triple bond.
Hydrocarbons are the compounds of
carbon and hydrogen.
identify the branch of Chemistry??
Answer:
organic chemistry
because it is study of carbon containing substances
Organic chemistry is the branch of Chemistry where hydrocarbons are the compounds of carbon and hydrogen.
What is organic chemistry?Organic chemistry is the study of the structure, properties, composition, reactions, and preparation of carbon-containing compounds.
Hydrocarbons Derivatives are compounds which are made up of hydrogen and carbon with specific functional groups attached to them.
Examples:- Aldehydes, ketones, carboxylic acids, alcohols, alkyl halides, ethers, amines etc.
Hence, organic chemistry is the branch of Chemistry where
hydrocarbons are the compounds of carbon and hydrogen.
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Why is John Dalton known as the originator of atomic theory?
Answer:
he thought of atoms first
Answer:
He was the first to be the one to propose that matter is made out of atoms. He also proved that the atoms are divisible in nature.
Which of the following statements is true? Less rain and snow falls in smoky areas than in other areas. Acid rain causes corrision of buildings and statues. The first laws againts pollution were passed in the 1990s. Cars are the leading cause of nitrogen oxide pollution.
Answer:
Acid rain causes corrosion in buildings.
Explanation:
This is true because acid rain over time can eat away at the building.
Connie was making sodium chloride by adding an acid to an alkali. She followed the progress of the reaction with a pH sensor .What else could she have used to detect when the reaction was complete?
What Connie could have used to detect when the chemical reaction was complete is an: acid-base indicator.
A chemical reaction is a chemical process that involves the continuous rearrangement (transformation) of either the ionic, atomic or molecular structure of a chemical element through the breakdown and formation of chemical bonds, in order to produce a chemical compound.
When a strong acid such as Hydrogen chloride (HCl) react with a strong alkali such as Sodium hydroxide (NaOH), it gives rise to the formation of Sodium chloride (NaCl) and Water ([tex]H_2O[/tex]);
[tex]HCl + NaOH[/tex] ----> [tex]NaCl + H_2O[/tex]
The progress of the above chemical reaction can be followed by using a pH sensor and the final pH of a strong acid and strong base is seven (7), meaning it is neutral.
However, Connie could make use of an acid-base indicator to detect when the chemical reaction is complete.
An acid-base indicator can be defined as a chemical substance that changes color with respect to the pH (hydrogen ion concentration) of a solution or chemical reaction. Some examples of an acid-base indicator are:
Litmus paper.Methyl red.Red cabbage juice.Bromothymol blue.Methyl orange.Phenolphthalein.In conclusion, an acid-base indicator is typically used for detecting when a chemical reaction between an acid and an alkali is complete.
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Answer:When a strong acid such as Hydrogen chloride (HCl) react with a strong alkali such as Sodium hydroxide (NaOH), it gives rise to the formation of Sodium chloride (NaCl) and Water ();
---->
Explanation:
Explain contribution of Mendleev for arrangement of elements in his periodic table
Answer:
Mendeleev arranged the elements in order of increasing relative atomic mass. When he did this he noted that the chemical properties of the elements and their compounds showed a periodic trend. He then arranged the elements by putting those with similar properties below each other into groups.
-- He left gaps for yet to be discovered elements
-- He switched the order of a few elements to keep the groups consistent
-- He was the first scientist to give the periodic law.
the general formula for the alkane series is:
Answer:
The alkanes comprise a series of compounds that are composed of carbon and hydrogen atoms with single covalent bonds. This group of compounds comprises a homologous series with a general molecular formula of C n H 2 n+2 , where equals any integer.
Explanation:
The general formula for the alkane series is CnH2n+2
General formula for the alkane series:In this formula:
"Cn" shows how many carbon atoms are in the alkane molecule.
"H2n+2" shows the amount of hydrogen atoms in the alkane compound, with "n" being the number of carbon atoms.
Alkanes are a group of hydrocarbons that only have single bonds between their carbon atoms. The formula says that each carbon atom is connected to two hydrogen atoms. And the total number of hydrogen atoms in an alkane molecule is two more than double the number of carbon atoms.
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Describe how a polyploid is formed
Answer:
ExpPolyploidy is the heritable condition of possessing more than two complete sets of chromosomes. Polyploids are common among plants, as well as among certain groups of fish and amphibians. For instance, some salamanders, frogs, and leeches are polyploids. Many of these polyploid organisms are fit and well-adapted to their environments. In fact, recent findings in genome research indicate that many species that are currently diploid, including humans, were derived from polyploid ancestors (Van de Peer & Meyer, 2005). These species that have experienced ancient genome duplications and then genome reduction are referred to as paleopolyploids. This article discusses the mechanisms underlying polyploidy, and both the advantages and disadvantages of having multiple sets of chromosomes.
Mechanisms of Polyploidy
This diagram shows several pathways by which diploid species can transition to polyploid species and polyploid species can transition to diploid species. Each species is represented by an oval containing two or more colored circles. Each colored circle represents a complete set of chromosomes.
View Full-Size ImageFigure 1
Figure Detail
How does an organism become polyploid? Polyploids arise when a rare mitotic or meiotic catastrophe, such as nondisjunction, causes the formation of gametes that have a complete set of duplicate chromosomes. Diploid gametes are frequently formed in this way. When a diploid gamete fuses with a haploid gamete, a triploid zygote forms, although these triploids are generally unstable and can often be sterile. If a diploid gamete fuses with another diploid gamete, however, this gives rise to a tetraploid zygote, which is potentially stable. Many types of polyploids are found in nature, including tetraploids (four sets of chromosomes), hexaploids (six sets of chromosomes), and other chromosome-pair multiples
what part of the brain helps you see and think
Answer:
Mark me brainliest
what is the difference between cells, tissues and organs
Answer:
A group of cells working together is defined as a tissue and several tissues working together comprise an organ.
Explanation:
Condensation refers to the process when
A gas turns to a liquid
A liquid turns to a gas
A liquid turns to a solid
A solid turns to a liquid
Answer:
A Gas turns to a liquid
Explanation:
How many electrons must calcium lose to satisfy the octet rule?
Gain 2 electrons
Lose 2 electrons
Lose 40 electrons
Lose 20 electrons
• Previous
Next >
Answer:
Lose 2 electrons
Explanation:
What is chemical potential energy?
Answer:
It is the energy that is stored in bonds that hold particles together
Explanation:
If you wanted to perform a controlled experiment to test the effect of temperature on the pressure of a bicycle tire, which of the following would be necessary?
Why does the structure of the plasma membrane make this type of transport necessary for fluids
Answer: because the phospholipid bilayer formed by these interactions makes a good barrier between the interior and exterior of the cell, because water and other polar or charged substances cannot easily cross the hydrophobic core of the membrane.
Explanation:
a student balanced the chemical equation for the reaction of magnesium with oxygen by writing Mg + O2 ----> MgO2. What is wrong with this equation?
Answer:
Explanation:
Magnesium when it oxidizes has a valence of 2.
Oxygen, when it mixes with something, has a valence of - 2
So Mg and O2 will form something, but what? The answer is MgO
Mg + O2 ===> MgO
To balance this equation, you need 2 Magnesiums on the right and 2 Oxygens also on the right. The left will need a two Magnesiums.
The balanced equation will be
2Mg + O2 ====> 2MgO
plsss answer this?? i need help
Answer:
85.34 g of oxygen
Explanation:
Carbon and Oxygen combine in ratio 3:8 to form CO2
Weight of C = 32g
3g of carbon reacts with 8g of oxygen
1g of carbon reacts with 8/3 g of oxygen
32 g of carbon reacts with 8/3 (32)
= 256/3
= 85.34 g of Oxygen
Hope it helps....
The lifting force on an airplane's wing does which of the following?
O A. Increases gravity
O B. Increases with speed
O C. Decreases with speed
D. Overcomes drag
The lifting force on an airplane's wing Increases with speed.
What is lifting force?The lifting pressure, lifting force, or virtually lift is the sum of all of the forces on a body that forces it to transport perpendicular to the route of flow.
Drag and Thrust are all “mechanical forces.” A mechanical force is generated through the interplay between an item and a fluid (liquid or gas). Weight is a “field force.” A subject's pressure no longer has to be in physical contact with the item to have an impact on the object.
The lift equation states that carry L is identical to the carry coefficient Cl times the density r times half of the velocity V squared instances the wing region A. For given air conditions, form, and inclination of the item, we have to decide a value for Cl to determine the raise.
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3. Sugar solution(sugar + water) is a homogeneous mixture and sugar can be separated from water through evaporation .Comment.
Plz, answer
Answer:
water is the answer
Explanation:
The sugar and water mix to make sweet water but the sun extracts the sugar from the water leaving only normal water
Answer:
water can be evaporated
Explanation:
the water will be evaporated leaving only the sugar residue behind.
Read the following statements carefully: X: It is a thick black coloured liquid which is obtained from coal.Y: It was used earlier in railway engines to produce steam to run trains.Z : It is used to run heavy vehicles such as buses, trucks, tractors, etc.X, Y and Z respectively are
Options are not given in the question. The complete question is as follows:
Read the following statements carefully: X: It is a thick black coloured liquid which is obtained from coal.Y: It was used earlier in railway engines to produce steam to run trains.Z : It is used to run heavy vehicles such as buses, trucks, tractors, etc.X, Y and Z respectively are
A. a. Coal tar b. Coal c. Diesel
B. a. Coal b. Paraffin wax c. Petrol
C. a. Coke b. Coal tar c. Kerosene
D. a. Coke b. Coal c. Coal tar
Answer:
A. a. Coal tar b. Coal c. Diesel
Explanation:
Coal Tar is a thick black or dark brown colored liquid obtained from coal. Coal Tar consists of hydrocarbons and free carbon extracted from coal using a process of destructive distillation. So, X is coal tar.
Earlier coal was used to produce steam to run steam engine trains. Air flows are allowed to burn coal hotter, then the hot coal turns water to steam and helps in the locomotive steam engine to run. So, Y is coal.
Deisel is used to run heavy vehicles such as buses, trucks, tractors, etc. because diesel burns at slow speed and produces a higher torque that can move heavy automobiles. So, Z is deisel.
Hence, the correct option is A.
does a periodic table indicate the occurrence of elements
Answer:
no
Explanation:
it only shows the atomic number and basically the chemical behavior of the element
The compound represented by this formula can be classified as an
Answer:
It depends what formula you are talking about.
Explanation:
please further explain so I can be sure.
A certain man needed 400N of force to pull a load through a distance of 150cm in 8s . Calculatell i) the work done by man ii) the power developed by man
Answer:
a) 600 J
b) 75 W
Explanation:
Force= 400 N, distance = 150 cm = 1.5 m, time= 8s
a) Work is the product of force acting on an object and distance (or displacement). The S.I unit of work is the joules.
Work = force × distance = 400 × 1.5 = 600 J
b) Power is the amount of energy transferred per unit time. It is the ratio of work to time. The S.I unit of power is watt
Power = work/time = 600 / 8 = 75 W
Mitchell and his lab partner were conducting a titration experiment. Their goal was to neutralize 0.50 mol NaOH. How many moles of H2SO4 are needed to complete the neutralization? A) 0.25 mol B) 0.50 mol C) 1.00 mol D) 2.00 mol
Answer:
The answer is "Option A"
Explanation:
Given:
Moles in [tex]NaOH = 0.50[/tex]
The equation formula for [tex]NaOH[/tex]and[tex]H_2SO_4[/tex] reactions as follows:
[tex]2NaOH+H_2SO_4\rightarrow Na_2SO_4+2H_2O[/tex]
The reaction's stoichiometry:
If 2 moles of [tex]NaOH[/tex] react with 1 [tex]H_2SO_4[/tex] mole
Thus 0.50 [tex]NaOH[/tex] moles react with = [tex]\frac{1}{2} \times 0.50[/tex] [tex]H_2SO_4[/tex] moles
So, the final value is= 0.25
