The translation of the question is
250 g of alcohol have been put in a glass together with 2 g of iodine, which dissolve completely. Calculate the concentration of the solution in% by mass?
Answer:
The %mass by mass of the given solution is 0.794%
Explanation:
We are given
Mass of solute(Iodine) = 2g
Mass of the solvent (Alcohol) = 250g
Since the Iodine dissolves completely in Alcohol
Total mass of the solution = 250 + 2 = 252g
the formula of concentration of the solution in % by Mass is given by
%[tex]\frac{w}{W} = \frac{Mass of the solute*100}{Total mass of the solution}[/tex]
%w/W = [tex]\frac{2*100}{252}[/tex]
= 0.794%
Therefore the %mass by mass of the given solution is 0.794%
What did the Curies conclude about radioactivity based on their studies?
A. The amount of radioactivity is an extensive property because it varies as the amount of material varies.
B. The amount of radioactivity is an extensive property because it remains constant as the amount of material varies.
C. The amount of radioactivity is an intensive property because it varies as the amount of material varies.
D. The amount of radioactivity is an intensive property because it remains constant as the amount of material varies.
Answer:
c
Explanation:
Explain why heating a liquid causes it to evaporate more quickly.
Answer:
If a liquid is heated the particles are given more energy and move faster and faster expanding the liquid. The most energetic particles at the surface escape from the surface of the liquid as a vapour as it gets warmer. Liquids evaporate faster as they heat up and more particles have enough energy to break away.
Explanation:
Who was Alexander Fleming
Sir Alexander Fleming (6 August 1881 – 11 March 1955) was a Scottish physician and microbiologist, best known for discovering the enzyme lysozyme and the world's first broadly effective antibiotic substance which he named penicillin.
For this discovery he shared the Nobel Prize in Physiology or Medicine in 1945 with Howard Florey and Ernst Boris Chain.
he was a british doctor, born in august 6, 1881. he was also known as pharmacologist.
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What does one mole of oxygen and one mole of carbon dioxide have in common?
Answer:
Equal number of moles
Explanation:
Thats life
Chlorine has two natural isotopes, chlorine-35 and chlorine-37.
Describe the effect these isotopes have on the relative atomic mass of chlorine
Answer:
The relative atomic mass of chlorine depends on the ratio between the abundance of these two naturally-occurring isotopes.
Explanation:
The relative atomic mass of an element is a weighted average of the atomic mass of its naturally-occurring isotopes. The relative abundance of each isotope gives its weight in this weighted average.
For these two naturally-occurring isotopes of chlorine:
The relative atomic mass of [tex]^{35}{\rm Cl}[/tex] is approximately [tex]34.969[/tex] daltons. The relative abundance of this isotope in nature is approximately [tex]0.758[/tex]. The relative atomic mass [tex]^{37}{\rm Cl}[/tex] is approximately [tex]36.966[/tex] daltons. The relative abundance of this isotope in nature is approximately [tex]0.242[/tex].[tex]\begin{array}{|c|c|c|}\cline{1-3} \text{Isotope} & \text{Atomic Mass} & \text{Relative Abundance}\\ \cline{1-3} ^{35}{\rm Cl} & \approx 34.968\; \rm Da} & \approx 0.758 \\ \cline{1-3} ^{37}{\rm Cl} & \approx 36.966\; \rm Da & \approx 0.242 \\ \cline{1-3}\end{array}[/tex].
[tex]\begin{aligned}&\text{relative atomic mass of Cl} \\ &= \text{atomic mass of $^{35}{\rm Cl}$} \times \text{relative abundance of $^{35}{\rm Cl}$} \\&\quad + \text{atomic mass of $^{37}{\rm Cl}$} \times \text{relative abundance of $^{37}{\rm Cl}$} \\ &\approx 34.968\; \rm Da \times 0.758 + 36.966\; \rm Da \times 0.242 \\ &\approx 35.45\; \rm Da \end{aligned}[/tex].
The relative abundance of [tex]^{35}{\rm Cl}[/tex] is much higher than that of [tex]^{37}{\rm Cl}[/tex]. Consequently, the relative atomic mass of the element [tex]\rm Cl[/tex] is closer to the atomic mass of [tex]^{35}{\rm Cl}\![/tex] than that of [tex]^{37}{\rm Cl}\![/tex].
Aluminum has the electronic configuration 2,8,3. How many valence
electrons are in the aluminum atom?
Answer:
3 valence electrons
Explanation:
Because aluminum has three, that means three fluorines can bond. The make the formula AlF3, also known as aluminum trifluoride. Each of the fluorine atoms gets an electron to fill their shell, and the aluminum loses three, giving it a filled shell too (remember, aluminum has three extra electrons).
Most metals are _____ at room temperature and generally have moderate to high melting and boiling points because the metallic bond is fairly strong. The melting point of a metal will _____ as atomic size increases because larger metal ions have a _____ attraction for the electron sea.
Answer:
solid
decrease
smaller
Explanation:
f
Write the structure of the following compound:
=> 3-(4-chlorophenyl)-2-methylpropane
Answer:
See explanation and image attached
Explanation:
The IUPAC system of nomenclature enables the structure of molecules to be written seamlessly from the name of the compound. Hence it is commonly called the systematic nomenclature.
The parent chain here is propane. It is substituted at the 2- position by a methyl group and at the 3-position by 4-chlorophenyl group as we can see in the image attached to this answer.
Isaac Newton lived and developed his Laws of Motion during which time period?
Answer:
saac Newton was a physicist and mathematician who developed the principles of modern physics, including the laws of motion and is credited as one of the great minds of the 17th-century Scientific Revolution.
Education: The King's School, University of Ca...
Birth Date: January 4, 1643
Death Date: March 31, 1727
Explanation:
Isaac Newton was a physicist and mathematician who developed the principles of modern physics, including the laws of motion and is credited as one of the great minds of the 17th-century Scientific Revolution.
hope it helps have a great day
Examine the EM spectrum chart. Describe what is happening as the EM spectrum goes
from Radio Waves to Gamma rays,
Vight
Uno
Somme
Morowaves
Infrared
Radio Waves
Woman
w
w
Wavelength
The amplitude increases
The wavelength increases
The wavelength decreases
The amplitude decreases
Answer:
The wavelength decreases
Explanation:
As you go along the EM spectrum from radio waves to gamma rays, the wavelength decreases as the wave's energy and frequency increase.
If you put a piece of zinc into a solution of copper (I) sulfate and allow the single replacement reaction to go to completion, how will you know which of the reactants is the limiting reactant? Write the balanced equation, including the states of matter of the reactants and products, to help support your answer.
Explanation:
Reaction of zinc metal in copper sulfate solution.
[tex]\begin{array}{ll}\text { Oxidation : } & \mathrm{Zn}(s) \rightarrow \mathrm{Zn}^{2+}(a q)+2 e^{-}\\\text {Reduction : } & \mathrm{Cu}^{2+}(a q)+2 e^{-} \rightarrow \mathrm{Cu}(s) \\\hline \text { Full Reaction : } & \mathrm{Zn}(s)+\mathrm{Cu}^{2+}(a q) \rightarrow \mathrm{Zn}^{2+}(a q)+\mathrm{Cu}(s)\end{array}[/tex]
Zinc is listed above copper on the activity series, this means that zinc is more easily oxidized than copper. That is why copper(II) ions can act as an oxidizing agent when put into contact with zinc metal. Ions of any metal that is below zinc, such as lead or silver, would oxidize the zinc in a similar reaction.
Ms. Terries was given a beautiful deep red gem. She knew she might be holding a ruby. Or, she might be holding a stone worth more than rubies, a stone rared than diamonds – a red beryl. Ms. Terries needed to be careful in her calculations. Red Beryl is a mixture of minerals and its density can be anywhere from 2.63g/cm3 to 2.92 g/cm3 Rubies can also vary in density from 3.9 g/cm3 to 4.1 g/cm3. Ms. Terries weighed the stone. It weighed 4.35 g. When put into a graduated cylinder of water, the water level rose 1.5 mL. Determine the density of the gem. Was it ruby or red beryl?
Answer:
red beryl
Explanation:
Red Beryls = Density range is 2.63g/cm3 to 2.92 g/cm3
Rubies = Density Range is 3.9 g/cm3 to 4.1 g/cm3
Mass of stone = 4.35 g
Volume of solid = change in water level = 1.5 mL = 1 cm3
Relationship between mass, volume and density is given by;
Density = Mass / Volume
Density = 4.35 / 1.5 = 2.9 g/cm3
The density of the stone falls in the red beryls range hence it is a red beryl.
Which of the following correctly describes a proton? Group of answer choices Location: nucleus, contribution to mass: usually about half, charge: positive Location: nucleus, contribution to mass: virtually none, charge: positive Location: outside nucleus, contribution to mass: usually about half, charge: positive Location: nucleus, contribution to mass: usually about half, charge: none
Answer:
Location: nucleus, contribution to mass: usually about half, charge: positive
Explanation:
Protons are a part of the nuclear particles alongside the neutrons. Protons and neutrons are all together called sub-atomic particles and they share the nucleus at the center of an atom together.
Protons carry positive charges. They determine the mass of the atom alongside the neutrons. They contribute half to the mass of an atom and the other part is lies on the mass of a neutron. Neutrons do not carry any charges.Given the equation representing a reaction: H + H --> H2, explain in terms of energy what is happening as the bond is being formed
Answer:
The formation of the bond releases energy. This is because the individual hydrogen atoms are more unstable than when they are joined together. Stability brings about the release of energy, and this would be an exothermic reaction.
14. Which of the following involves a chemical change?
A.mixing
b. melting
grinding
d. decomposing
Answer:
D. decomposing
General Formulas and Concepts:
Chemistry
Chemical vs Physical ChangesExplanation:
A would be incorrect because mixing 2 things together doesn't necessarily create a chemical change. Take oil and water for example. You can mix the 2 and it would not have a chemical change.
B would be incorrect because you are simplify changing the state of matter of the object. Iron in solid form is still iron in liquid form; there is no chemical change.
C would be incorrect for similar reasons as B. You are simply changing the state of matter.
D would be the remaining and correct answer. Decomposing changes one object into a different one by chemically changing.
Mg + 2 AgNO₃ → Mg(NO₃)₂ + 2 Ag How many grams of magnesium nitrate, Mg(NO₃)₂, are formed when 9.87 moles of silver nitrate, AgNO₃, react?
Mass of Magnesium nitrate formed : 731.86 g
Further explanationA reaction coefficient is a number in the chemical formula of a substance involved in the reaction equation. The reaction coefficient is useful for equalizing reagents and products.
Reaction
Mg + 2AgNO₃ → Mg(NO₃)₂ + 2 Ag
moles of silver nitrate, AgNO₃ = 9.87
mole ratio AgNO₃ : Mg(NO₃)₂ = 2 : 1, so mol Mg(NO₃)₂ :
[tex]\tt \dfrac{1}{2}\times 9.87=4.935[/tex]
mass of Mg(NO₃)₂(MW=148,3 g/mol) :
[tex]\tt mass=mol\times MW\\\\mass=4.935\times 148,3\\\\mass=731.86~g[/tex]
Nitrogen gas is cooled and its volume went
from 375 mL to 255 mL. If the final
temperature is -45 °C, what was the original
temperature?
For which each question , which box do I mark?
Answer:
A
B
A
B
B
Explanation:
B - MIXTURE
A - COMPOUND
In your own words, define the following terms.
1 Blood
2 Lymph
3 Alveoli
Answer:
BLOOD - the definition of blood is the fluid carries oxygen
Explanation:
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How does one determine how much of a molecule is produced in a reaction?
O A. Oxidation states are used to calculate the number of product molecules.
B. The molar masses of the molecules tell how many grams of product will form.
O c. The coefficients and molar masses are used to calculate amounts of molecules
D. The mass of the products is determined by adding the mass of the reactants.
Answer:
c
Explanation:
i doubt it
The coefficients and molar masses are used to calculate the amounts of molecules. Hence, option C is correct.
What is a molecule?The smallest particle of a substance has physical and chemical properties of that substance. Molecules are made up of one or more atoms.
A molecule can be determined by how much is produced in a reaction through the coefficients and molar masses are used to calculate the amounts of molecules.
Hence, option C is correct.
Learn more about molecules here:
https://brainly.com/question/14130817
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Which reverses the flow of current through an electric motor?
A brush
B battery
C armature
D commutator
Answer:
D
Commutator is the answer
Explanation:
The commutator systematically converts the current direction between the rotor and the outer circuit. As the shaft revolves, the commutator converts the course of current in a winding. For a separate armature winding, when a cylinder has reached one-half perfect turn, the winding is now attached so that current passes through it in the reverse of the original direction.
Answer:
D. Commutator
Explanation:
I just took the quiz. credit to the person above me.
materials that prevent the heat to flow call
Answer:
Materials that prevent heat to flow are known as heat insulators.
Explanation:
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if hydrochloride tablets and MP4 format you find the attachment photograph and signature
answer is attached in the image below
Answerme espanol amigo me
Explanation:
I will give you 100 points and mark you as brainilest if you answer the whole thing correctly.
Answer:
1.)[tex]Al_{2} O_{3}[/tex]
2.) [tex]Li_{3} N\\[/tex]
3.) 2HCl
4.) MgO
5.) Mg and [tex]O_{2}[/tex]
6.) [tex]H_{2}[/tex] and [tex]O_{2}[/tex]
7.)Na and [tex]Br_{2}[/tex]
8.) 3 aluminums and 3 chlorides
Explanation:
As you move down a group, you will recall that the radius increases. Why do you think an increase in atomic radius would result in a lower ionization energy?
Answer:
Because as we move down the group size/ radius of atom increases due to increase in shells and screening effect. The hold of nucleus on valence electrons decreases and effective nuclear charge decreases so it is easy to remove electron from greater sized atoms as compared to smaller sized aroms.
Energy required to remove electron is ionization energy so greater sized atoms have low ionization energy.
Explanation:
what is the momentum of a 3 kg bowling ball moving at 3 m/s
Answer:
9 kg.m/sExplanation:
The momentum of an object can be found by using the formula
momentum = mass × velocity
From the question we have
momentum = 3 × 3
We have the final answer as
9 kg.m/sHope this helps you
The structures of three hydrocarbons are given below : a. They have same physical properties. B.They have same structural formula. c.They have same general formula. D.They are isomers of each other.
Answer:
The correct answer is option C "They have same general formula"
Explanation:
Hydrocarbons are any of a class of natural substance intensifies made distinctly out of the components carbon (C) and hydrogen (H). The carbon particles consolidate to shape the structure of the compound, and the hydrogen molecules append to them in various arrangements.
Hydrocarbons are the chief constituents of oil and gaseous petrol. They fill in as powers and ointments just as crude materials for the creation of plastics, strands, rubbers, solvents, explosives, and modern chemical substances.
All of the compounds given are alkanes and they have the same general formula which is represented by CnH2n+2, where ‘n’ is the number of carbon atoms.
guys, how do i know whether the forces of attraction is strong or weak?
Answer:
Whether the forces of attraction is strong or weak is explained below in details.
Explanation:
There are three distinct kinds of intermolecular forces in expressions of energy. They are (strongest to weakest) dipole-dipole, hydrogen bonding, and Van der Waals' strengths. Intermolecular forces are weak related to intramolecular forces – the energies which endure a molecule collectively. For instance, the covalent bond, including distributing electron sets among atoms, is much more powerful than the forces impersonate among neighboring molecules.
Which statement is true about water's density and the survival of marine life? view attachment
Write your thoughts or ideas about the lesson on types of soil.
Answer:
There are different types of soil in the earth. Those different types of soil helps the earth stay healthy in many ways!! Just like the different layers in the earth. There are so many different layers in the earth so that the plants get the different nutrition they need. Not only that but it cleans the water that soaks in the ground.
There are 6 different types of soil, they are; sandy soil, clay soil, silt soil, peat soil, chalk soil, and loam soil.
Explanation:
Sandy soil
Sandy Soil is light, warm, dry and tend to be acidic and low in nutrients. Sandy soils are often known as light soils due to their high proportion of sand and little clay (clay weighs more than sand). These soils have quick water drainage and are easy to work with. They are quicker to warm up in spring than clay soils but tend to dry out in summer and suffer from low nutrients that are washed away by rain. The addition of organic matter can help give plants an additional boost of nutrients by improving the nutrient and water holding capacity of the soil.
Clay Soil
Clay Soil is a heavy soil type that benefits from high nutrients. Clay soils remain wet and cold in winter and dry out in summer. These soils are made of over 25 percent clay, and because of the spaces found between clay particles, clay soils hold a high amount of water. Because these soils drain slowly and take longer to warm up in summer, combined with drying out and cracking in summer, they can often test gardeners.
Silt Soil
Silt Soil is a light and moisture retentive soil type with a high fertility rating. As silt soils compromise of medium sized particles they are well drained and hold moisture well. As the particles are fine, they can be easily compacted and are prone to washing away with rain. By adding organic matter, the silt particles can be bound into more stable clumps.
Peat Soil
Peat soil is high in organic matter and retains a large amount of moisture. This type of soil is very rarely found in a garden and often imported into a garden to provide an optimum soil base for planting.
Chalk Soil
Chalk soil can be either light or heavy but always highly alkaline due to the calcium carbonate or lime within its structure. As these soils are alkaline they will not support the growth of ericaceous plants that require acidic soils to grow. If a chalky soil shows signs of visible white lumps then they can’t be acidified and gardeners should be resigned to only choose plants that prefer an alkaline soil.
Loam Soil
Loam soil is a mixture of sand, silt and clay that are combined to avoid the negative effects of each type. These soils are fertile, easy to work with and provide good drainage. Depending on their predominant composition they can be either sandy or clay loam. As the soils are a perfect balance of soil particles, they are considered to be a gardeners best friend, but still benefit from topping up with additional organic matter.
Those are the different types of soils with all of their many uses. I hope this helps!!!!! Have a wonderful day!!!