Explanation:
Calculate the "m" and "M" of a percentage concentration of 45% m / m, which has a solution D 1.25 g / ml and a mass of 125g.
Given data is:
The mass % of the solution is 45%.
The density of the solution is 1.25 g/mL.
The mass of the solution is 125 g.
Molarity of solution is:
[tex]M=\frac{number of moles of solute}{volume of solution}[/tex]
The volume of the solution is:
[tex]Volume=\frac{mass}{density} \\=125 g / 1.25 g/ml\\=100 mL[/tex]
From mass% of the solution, the mass of solute HNO_3 can be calculated.
[tex]mass percent=\frac{mass of solute}{ mass of solution} \\45=(mass of HNO_3/125 g)x100\\\\mass of solute = 56.25g[/tex]
The number of moles of HNO3 is :
[tex]n_H_N_O__3=\frac{m_H_N_O__3}{M_H_N_O__3}[/tex]
[tex]=56.25 g/63.00g/mol\\\\=0.893mol[/tex]
The molarity is:
[tex]M=n/V\\M=0.893 mol/0.1L\\M=8.93 M[/tex]
The molality is:
[tex]m=n/mass of solvent in kg\\ =0.893 mol /(0.125-0.05625)kg\\ = 12.9 m[/tex]
En una carrera de atletismo un deportista se muestra agotado sin fuerzas para continuar y decide abandonar la carrera ¿Que alimentos tomo antes de la carrera ?
Answer:
Los alimentos para evitar la fatiga durante una carrera son alimentos bajos en grasas y altos en carbohidratos, así como alimentos bajos en fibra como pan, mantequilla de maní, plátano, jugo de frutas sin pulpa, y beber hasta aproximadamente 600 ml de líquido aproximadamente 3 horas. antes de la carrera
La comida para comer unos días antes de la carrera incluye carnes magras, arroz, pasta y verduras con contenido de almidón.
Los alimentos que se deben evitar incluyen carne roja, alimentos con alto contenido de grasas saturadas, alimentos fritos, pasteles y salchichas.
Explanation:
I pls help me this is the question:
define the following terms below
Answer:
natural resources: materials or substances such as minerals, forests, water, and fertile land that occur in nature and can be used for economic gain.
renewable resources: a natural resource that is unlimited or that is naturally replenished rather quickly, such as sunlight or water
non renewable resources: (also called a finite resource) is a natural resource that cannot be readily replaced by natural means at a pace quick enough to keep up with consumption.
are these following a basic radical or acid radical?
1. Chlorate
2. Peroxide
3. Silver
4. Zinc
5. Nitrite
Answer:
chlorate=Acid
peroxide=Acid
silver=Acid
zinc= Basic
nitrite=Acid
how is electrovalent bond formed ? Describe with an example .
Answer:
For example, the bond between the sodium and chlorine atoms in sodium chloride (NaCl) is formed by the transfer of an electron from sodium to chlorine, creating Na + and Cl – ions. ... The electrostatic attraction between these ions provides the bonding in NaCl.
A reaction happens quickest during:
A. The beginning of the reaction
B. It is constant throughout the reaction
C. The end of the reaction
D. The middle of the reaction
The reaction is the formation of the product from the reactants. A reaction happens quickest during the beginning of the reaction. Thus, option A is correct.
What are the factors affecting the reaction rate?The reaction rate is the pace at which the reaction takes place and the breakdown or the combination of the reactants to produce the products. The rate of reaction depends on the concentration of the reactants.
The concentration of the reactants is in direct proportion with the rate as at the beginning of a reaction there is a higher amount of substance present than at the end.
As the reaction proceeds, the reactants get consumed and their concentration decreases. As there is a decrease in concentration the rate of the reaction converting and producing the products also decreases.
Therefore, option. the rate of reaction is fast at the beginning.
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which of the following two conditions will favor a spontaneous reaction?
a) an increase in entropy and a decrease in enthalpy
b) an increase in both entropy and in enthalpy
c) a decrease in entropy and a decrease in enthalpy
d) a decrease in entropy and an increase in enthalpy
Two metals with equal mass will absorb heat according to their heat absorbing capacity.
The increase in entropy will cause the solid substance to break into multiple pieces.
When these solute particles detach from each other they will form a solution. Entropy increase will cause the temperature to increase.
Decrease in enthalpy is an exothermic reaction which releases heat from the reaction and then desired products will be formed.
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Why does the battery give a reading of 9V even though there are no electrons flowing around the circuit?
Answer:
because battery have it's own voltage in it's composition
What type of Nuclear decay is shown by the reaction below
Answer:
bete is your answer.
have a great day.
I think c ....is write answers
If the volume of a gas is decreased by changing the shape of the container, the number of collisions per area between the molecules and the container walls will increase. This corresponds to an increase in the gas pressure, which is the force exerted per area. What gas law is kinetic molecular theory of gases (KMT) explaining in this case
Answer:
If the volume of a gas is decreased by changing the shape of the container, the number of collisions per area between the molecules and the container walls will increase. This corresponds to an increase in the gas pressure, which is the force exerted per area.
Did you know that before pencil erasers were added on in 1858. people got rid of pencil markings
with white breadcrumbs? Which would erase pencil markings better, an eraser or white bread
crumbs?
Make a hyphotesis plz
Answer:
I guess eraser is better than bread crumbs
Erasers would be better than white bread or crumbs to erase the pencil marks because they would not leave any food marks on the paper and using bread crumbs.
What is an eraser?An eraser is an object of stationary which is used to remove pencil marks from the paper. It is used during writing, when we write something wrong, we could erase or remove the writing from the paper. It is very useful for small children because they usually make mistakes while studying.
Erasers are made from the milk of rubber plants. The milk is collected from the plants, and then it is mixed with chemicals and set down, and then cut into pieces.
Thus, Erasers would be preferable to utilizing bread crumbs or white bread because they would not leave any food stains on the paper after erasing the pencil markings.
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7. In a remote area of Columbia, kids have to travel to school on a zip-line!
Would school attendance increase if all kids has to get to school on a fun
zip line?
Make a hyphotesis
Help plz!!!
Answer:
yes
Explanation:
Kids like fun things, and school is not fun , so if kids got to go to school on a zipline, attendance would be through the roof!
what is plasma in chemistry
Explanation:
Plasma is an ionized gas, a distinct fourth state of matter. “Ionized” means that at least one electron is not bound to an atom or molecule, converting the atoms or molecules into positively charged ions.but plasma is present in human body too in a liquid form.
hope this helps you
have a nice day
A student wants to separate a mixture of salt and water in a laboratory (a) Describe how the student can obtain both salt and water from the salt solution
Answer:
okay so basically what you are being tested is if you know the difference between simple and fractional distillation and okay you can evaporate the mixture but you won't obtain water so you will use simple distillation to obtain both salt and water
Arrange the steps in order to describe how photons and carbon dioxide (CO2) contribute to the warming of Earth.
CO2 in the atmosphere absorbs infrared
photons.
CO2 in the atmosphere emits infrared photons back toward Earth.
Photons from the Sun strike Earth and become infrared photons.
Earth radiates infrared photons into the atmosphere
The Sun radiates sunlight (visible)
photons
The Sun radiates sunlight (visible) photons
Photons from the Sun strike Earth and become infrared photons.
Earth radiates infrared photons into the atmosphere
CO2 in the atmosphere absorbs infrared photons.
CO2 in the atmosphere emits infrared photons back toward Earth.
Certain gases are known to contribute towards global warming. Such gases are called greenhouse gases. The infrared rays from the sun are absorbed by these gases as they are re-emitted from the earth and re-emitted.
The sun radiates photons to the earth which is re-radiated into outerspace from the earth's surface. CO2 and other greenhouse gases absorbs these gases and re-emit them to the earth thereby causing a gradually rise in the temperature of the earth called global warming.
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which best describes nuclear energy?
A the energy that matter has due to the vibrations of its particles
B the energy an object has due to its chemical bonds
C the energy generated by a flow of electrons
D the energy stored inside the center of an atom
Answer:
The correct answer is - D. the energy stored inside the center of an atom.
Explanation:
Each atom has a small center in it called the nucleus and the energy that holds the nucleus or center of the atom together in the atom is known as nuclear energy.
It is the energy that is stored in the center of the atom and normally does not come out, however, in some radioactive atoms the sends some part of the energy as radiation.
Thus, the correct answer is - D. the energy stored inside the center of an atom.
define SI unit system
Answer:
The SI base units are the standard units of measurement defined by the International System of Units (SI) for the seven base quantities of what is now known as the International System of Quantities: they are notably a basic set from which all other SI units can be derived.
H3C6H507 + H2O + H3O+ + H2C6H507
acid
base
Explanation:
an acid will give away a proton and become a conjugate base.
A base will accept a proton and become a conjugate acid.
Convert 15,000 seconds into minutes
Answer:
250 minutes
Explanation:
60 seconds = 1 minute
15000 secods = 15000 / 60
1500 secons = 250 minutes
Organisms do not adapt as a result of competition for resources.
Answer:
The given statement is False.
The organisms adapt as a result of competition for resources. Different places have different organisms suited for that particular places.
The animals living at a particular place compete for the resources available and the nature selects the organism that has won the competition for resources.
The organisms are evolved as a result of competition for resources
Answer:
I just wanted to say the other person is totally right.
this statement is false.
Câu 6: Cho 4,2 gam este đơn chức no E tác dụng hết với dung dịch KOH ta thu được 4,76
gam muối natri. Vậy công thức cấu tạo của E có thể là:
If an atom has three shell and number of valence electrons are two. Is this element metal
or non-metal and why? Name the element and it’s valency.
Answer:
Metal
Element: Calcium
Valency: 2
Explanation:
To find the element, let's use the periodic table. (Look below)
We already went past 3 shells, just need the 2 electrons after it.
Just skip to the 4th row and count 2 to the right
We end up at Calcium.
Calcium is a metal and we're also on the alkaline earth metals column.
Calcium will need to lose 2 electrons to reach stability, so the valency is 2.
PLS HELP WILL GIVE BRAINLIEST
it is a simple chemistry question
i thought F has 9 electrons, so why does this structure show 8 electrons.
Answer:
The IUPAC structure only shows bond pairs and lone pairs. In the flouromethane structure above, there is only one bond pair and three lone pairs of electrons. Therefore there is one electron remaining, but since it doesn't not make up a pair, it is ignored in the structure but theoretically it is present.
[tex].[/tex]
Answer:
therefore there is one electron remaining , but since it doesn't make up a pair . It is ignored in the structure but theoretically it is present .
What is known about a reaction with a negative enthalpy?
A. The reaction is endothermic,
B. The reaction is spontaneous,
C. The reaction is exothermic,
D. The reverse reaction is favored,
Considering the definition of enthalpy of reaction, the correct answer is option C. a reaction with a negative enthalpy indicates that the reaction is exothermic.
Definition of enthalpy of reactionThe enthalpy of a chemical reaction as the heat absorbed or released when chemicals are transformed into a chemical reaction and it occurs at constant pressure.
The enthalpy is an extensive property, that is, it depends on the amount of matter present.
Finally, it must be taken into account that:
A reaction is called exothermic if its enthalpy of reaction is negative (that is, if the system gives up heat).A reaction is called endothermic if its enthalpy of reaction is positive (that is, if the system absorbs heat).SummaryIn summary, a reaction with a negative enthalpy indicates that the reaction is exothermic.
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Energy in the amount of 420 J is added to a 35 g sample of water at a temperature of 10°C. What is the final temperature of the water?
The final temperature of the water, T2 = 38.57°C
Temperature can be defined as a measure of the degree of hotness or coldness of a physical object (body). Thus, it is measured with a thermometer and its units are degree Celsius (°C), Fahrenheit (°F) and Kelvin (°K).
A calorie refers to the amount of heat required to raise the temperature of a gram of water by one (1) degree Celsius (1°C).
Given the following data:
Quantity of energy = 420JMass = 35 gramsInitial temperature, T1 = 10°CThe specific heat capacity of water is 4.2 J/g°C.
To find the final temperature of the water (T2):
Mathematically, the quantity of energy (heat capacity) is given by the formula;
[tex]Q = mcdt[/tex]
Where;
Q represents the heat capacity or quantity of heat.M represents the mass of an object.C represents the specific heat capacity of water.dt represents the change in temperature.Substituting the values into the formula, we have;
[tex]420 = 3.5 \; * \; 4.2 \; * \; dt[/tex]
[tex]420 = 14.7 \; * \; dt\\\\dt = \frac{420}{14.7}[/tex]
Change in temperature, dt = 28.57°C
Next, we would solve for the final temperature by using this formula;
[tex]dt = T2 - T1[/tex]
[tex]28.57 = T_{2} - 10\\\\T_{2} = 28.57 \; + \; 10\\\\T_{2} = 38.57[/tex]
Final temperature, T2 = 38.57°C
Therefore, the final temperature of the water, T2 is equal to 38.57°C
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what is the requirements to obtain citizenship?
please answer it correctly
Answer:
Age. ...
Residency. ...
Residence and Physical Presence.
Good Moral Character.
Attachment to the Constitution.
Language.
U.S. Government and History Knowledge.
Oath of Allegiance.
These are some requirements for obtaining citizenship .
precautive measures taken when using pooter
I guess ensuring that you don't suck the insects or specimen collected by ensuring there is a net in the pooter
The atomic number of silicon (Si) is 14. What's the electron configuration for silicon? Question 1 options:
A) [Ar] 3p5
B) [He] 1s2 2p6
C) [Ne] 3s2 3p2
D) [He] 2s2 3p2
Answer:
D.[Ne] 3S2 3P2
Explanation:
The electron configuration for silicon is [Ne] 3s² 3p². Hence Option (C) is correct.
What is elctronic configuration ?Electronic configuration, also called electronic structure or electron configuration, the arrangement of electrons in orbitals around an atomic nucleus.
The electron configuration of an element describes how electrons are distributed in its atomic orbitals.
Electron configurations of atoms follow a standard notation in which all electron-containing atomic subshells (with the number of electrons they hold written in superscript) are placed in a sequence.
Silicon belongs to group 14th and 3rd period.Therefore, The electron configuration for silicon is [Ne] 3s² 3p². Hence Option (C) is correct.
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Is backbonding is possible in BF4- ? If no then why?
Answer:
No, because Flourine can only form 1 bond, thus backbonding is not obtainable
Patience, a popular card game in Mendeleev's time, is also known as Go Fish.
A. True
B. False
Answer:
B. False
Explanation:
step by step explanation
Answer:
False
Explanation:
the smell spreads immediately after you burn agarbatti in this example what is your condition about intermolecular force
Answer:
The aroma of agarbatti spreads quickly once you burn it because the particles in the agarbatti move endlessly in all directions. Both, the air and aroma, have large intermolecular forces which is why the molecules of air scatter immediately once agarbatti is burned.
