PLEASE HELP ASAP!!!!!!!!!!!!!!!

Answer:

The Chinese civilization really has an exact chronology, and the historical period began in the first year of the Western Zhou Dynasty in 841 BC. Before that, only the lineage records of the kings were recorded. Therefore, the earliest origin of Chinese civilization has not yet been finalized. Although there are many records about the Xia Dynasty in the traditional literature, due to the late completion of the book, there is no recognized evidence of the existence of the Xia Dynasty and its previous history. Therefore, some people in the modern and modern historical circles have always questioned the existence of the Xia Dynasty. sex.

Explanation:

Gas law refers to the relationship between the temperature, volume and pressure of a gas.

The term gas law refers to the relationship between the temperature, volume and pressure of a gas.

6a) PV =nRT

P = nRT/V

P =  0.898 * 0.082 * 293/24.5

P = 0.88 atm

6b)  Number of  moles of helium = 2.82 g/4 g/mol = 0.705 moles

Pressure =  991 mm Hg or 1.3 atm

V = nRT/P

V = 0.705 * 0.082 * 300/1.3

V = 13.3 L

8a) V = nRT/P

V = 0.814 * 0.082 * 273/1

V = 18.22 L

8b) 1 mole of oxygen occupies 22.4 L

1.21 mole of oxygen occupies   1.21 mole *  22.4 L/ 1 mole

= 27.1 l

9b) C4H10(g) + 13/2O2 -----> 4CO2 + 5H20

1 moles of butane produces 4 moles of CO2, It then follows that the volume of carbon dioxide produced is 4( 7.95 liters) = 31.8 litres

10b) CaCO3 ------> CO2 + CaO

Since the reaction is 1:1,  0.504 mol of CO2 is produced

PV =nRT

V = 0.504 * 0.082 * 273/1 atm

V = 11.3 L

Learn more about the ideal gas equation:https://brainly.com/question/79835

#SPJ1

Answer:

1. Used in many smoke detectors for homes and businesses to measure levels of toxic lead in dried paint sample to ensure uniform thickness in rolling processes like steel and paper production and to help determine where oil wells should be drilled.

2.Used to treat cancerous tumors to measure correct patient dosages of radioactive pharmaceutical to measure and control the liquid flow in oil pipelines to tell researchers whether oil wells are plugged by sand and to ensure the right fill level for packages of food, drugs, and other

products.

3.Used in medical diagnosis

4.Used to treat thyroid disorders. (Graves’s disease).

5.Used in molecular biology and genetics research.

6.Used in nuclear medicine for lung ventilation and blood flow studies.

7.Used in dental fixtures like crowns and dentures to provide a Uranium-234 natural color and brightness.

8.Used in electric blanket thermostats and to gauge the thickness of thin plastics, thin sheet metal, rubber, textile and paper.

You would have to fix the tilt of the Moon's orbit and make the Moon orbit planet Earth within the same plane that the Earth orbits the Sun.

A lunar eclipse can be defined as a phenomenon which occurs when the planet Earth comes in between the Moon and the Sun, thereby causing the Earth to cover the Moon with its shadow.

In order to have a lunar eclipse occur every month, you would have to fix the tilt of the Moon's orbit and make the Moon orbit planet Earth within the same plane that the Earth orbits the Sun, so as to block any ray of sunlight from reaching the Moon.

Read more on lunar eclipse here: https://brainly.com/question/17067406

#SPJ1

Answer:

I don't know the answer, but I can give options :)

Explanation:

A gas such as carbon monoxide would be most likely to obey the ideal gas law at:

Option 1) High temperatures and low pressure.

Option 2) Low temperatures and high pressure.

Option 3) High temperatures and high pressure.

Option 4) Low temperatures and low pressure.

Answer:

The gas must occupy 0 volume at -273°celcius

The pH of the resulting solution is 2.82.

pH is the measure of acidity and alkalinity of a solution , It has a range of 1 to 14.

HCl          +                   NaOH      →         NaCl       +         H₂O

0.0040                         .0025                 0                       0

0.0040 -0.0025             0                   0.0025          0.0025

Moles of HCl = 0.0015

As 0.0025 moles of NaOH reacts with 0.0025 moles of HCl leaving behind 0.0015 moles of HCl

Concentration of HCl = 0.0015/ 1 = 0.0015 M

[ H⁺] = 0.0015 M

pH = -log [ H⁺]

pH = -log [ 0.0015]

pH = 2.82

Therefore the pH of the resulting solution is 2.82.

To know more about pH

https://brainly.com/question/15289741

#SPJ1

Answer:

1) open system is the system through which both matter and energy and enter as well as leave

ex - open beaker

2) close system is the system through which only energy can leave but matter cannot

ex - pressure cooker.. ( energy leave as air)

3) Valency of an atom is the no. of outer most electron which can participate in a reaction.

4). Heisenberg uncertainty principal states that it is impossible to measure or calculate exactly, both the position and the momentum of an object

5) The reaction in which heat is required to make products are called endothermic reaction. it cools down the surrounding .

Answer:

The answer is B, to convert kelvin to temperature you :

Subtract 273 (k - 273)

Answer:

Π = 21.9 atm

Explanation:

The equation used to find osmotic pressure is:

Π = iMRT

In this formula,

   >> Π = osmotic pressure (atm)

   >> i = van't Hoff factor

   >> M = molarity (M)

   >> R = constant (0.0821 atm*L/mol*K)

   >> T = temperature (K)

Remember, van't Hoff factor is the amount of ions the species (MgCl₂) dissociates into while in solution. MgCl₂ dissociates into 3 ions. These ions are Mg²⁺ and 2 Cl⁻.

The temperature needs to be in Kelvin....

37.0 °C + 273.15 = 310.15 K

You now know the value of all the variables.

Π = iMRT

Π = (3)(0.287 M)(0.0821 atm*L/mol*K)(310.15 K)

Π = 21.9 atm

6.349 g mass of anhydrous magnesium sulfate will remain.

A mole is defined as 6.02214076 × 1023 of some chemical unit, be it atoms, molecules, ions, or others. The mole is a convenient unit to use because of the great number of atoms, molecules, or others in any substance.

Molar mass MgSO₄.7 H₂O = 246.52 g/mol

[tex]Moles =\frac{mass}{molar \;mass}[/tex]

[tex]Moles =\frac{13.0 g}{246.52}[/tex]

0.0527 moles

Molar mass MgSO₄ = 120.4 g/mol

Mass of anhydrous magnesium sulfate :

( 0.0527 x 120.4 ) => 6.349 g

Learn more about moles here:

https://brainly.com/question/8455949

#SPJ1

The molar mass of the unknown gas is determined as 17.75 g.

The rate of gas diffusion is given by Graham's law.

R₁√M₁ = R₂√M₂

where;

[tex]\frac{R_1}{R_2} = \sqrt{\frac{M_2}{M_1} } \\\\\frac{2R_2}{R_2} = \sqrt{\frac{71}{M_1} }\\\\2 = \sqrt{\frac{71}{M_1} }\\\\2^2 = \frac{71}{M_1} \\\\M_1 = \frac{71}{4} \\\\M_1 = 17.75 \ g[/tex]

Learn more about rate of diffusion here:  https://brainly.com/question/11197959

#SPJ1

The hazard symbol that pesticides have are skull and cross bones.

Hazard symbols represent those symbols that are used as a warning sign towards materials that are dangerous to health.

Example of symbols used are:

Therefore, the hazard symbol that pesticides have are skull and cross bones.

Learn more about pesticides here:

https://brainly.com/question/6589507

#SPJ1

The hazard symbol of pesticides is a picture of the skull and crossbones.

Pesticides are known as  substances that are meant to control or destroy pests. They include herbicide, insecticide, nematicide, avicide, rodenticide, bactericide, insect repellent, etc.

The hazard symbol of pesticides is a picture of the skull and crossbones

Thus, the hazard symbol of pesticides is a picture of the skull and crossbones.

Read more about pesticides here:

https://brainly.com/question/6662547

#SPJ1

Answer:

kliujhygfdsalikumjyhbtgvf

Explanation:

The answer is:

28

I just got this answer so I don't know how to work it out but i hope it helps.

HgS will precipitate first when tiny amounts of sulfide ion are slowly added to the solution.

The solubility product constant, Ksp​, is the equilibrium constant for a solid substance dissolving in an aqueous solution. It represents the level at which a solute dissolves in solution.

If Solubility product is greater than the ionic product then no precipitate will form on adding more solute because unsaturated solution is formed.

If Solubility product is lower than the ionic product then excess solute will precipitate out because of the formation of super saturated solution.

Here, Ksp value of HgS is very low. Hence, HgS will precipitate first when tiny amounts of sulfide ion are slowly added to the solution.

Learn more about Ksp here:

https://brainly.com/question/4637627

#SPJ1

Answer:

Brainly or Chegg tutors.

Explanation:

Try those!

Answer:

15

Explanation:

I got it right I just had the answer

They are converted into a single “o” when "ao" or "oo" are together when naming covalent bonds.

A covalent bond consists of the mutual sharing of one or more pairs of electrons between two atoms.

Sometimes, while naming the chemical compounds, a problem arises when compounds with “ao” and “oo” are written with -ide name. Conventionally, they are converted into a single “o”.

For example, the “ao” in the dichlorine hept-ao-xide ([tex]Cl_2O_7[/tex]). This “ao” in the [tex]Cl_2O_7[/tex] can be converted into “o”. As the result, the correct name of this compound would be dichlorine hept-o-xide.

Hence, they are converted into a single “o” when "ao" or "oo" are together when naming covalent bonds.

Learn more about the covalent bond here:

https://brainly.com/question/12661797

#SPJ1

There are three sigma bonds, so hybridization of the molecule will be sp²

The frequency of the green light emitted by a hydrogen atom with a wavelength of 525 nm is [tex]5.71[/tex]×[tex]10^{14} s^{-1}[/tex]

What is wavelength?

What is a frequency?

Wavelength=525nm

The relation between wavelength and frequency

[tex]v=\frac{c}{lambda}[/tex]

[tex]v=[/tex]frequency

[tex]c=[/tex]speed of light = [tex]3.0[/tex]×[tex]10^{8}[/tex][tex]m/sec[/tex]

λ(lambda)=wavelength

substitute the value in the equation mentioned above

[tex]v=3.0[/tex]×[tex]10^{8}[/tex][tex]/525[/tex]×[tex]10^{-9}[/tex]

[tex]=5.71[/tex]×[tex]10^{14}[/tex][tex]s^{-1}[/tex]

hence, the frequency of the green light emitted by a hydrogen atom with a wavelength of 525 nm is [tex]5.71[/tex]×[tex]10^{14} s^{-1}[/tex]

learn more about hydrogen emission here:

https://brainly.com/question/27231030

#SPJ10

c option is correct answer

The experimental investigations allow for the control of variables.

The control of variables is the experimental element that remains constant and unchanged throughout the experiment of the investigation.

The control of variables is held constant during the experiment to test the relation between the dependent and independent variables.

Thus, An experimental investigation allows the control of variables all the time.

Learn more about the experimental investigation, then click here to visit;

https://brainly.com/question/11934994

#SPJ1

The percent of water in the hydrated salt will be 55.08 %

Mass is a numerical measure of quantity, which is a basic feature of all matter. The kilogram is the international system of units of mass.

Given data;

Mass of crucible, cover, and contents before heating = 23.4 g.

Mass of empty crucible and cover = 18.82 g.

Mass of crucible, cover, and contents after heating to constant mass = 20.94 g.

⇒Mass of hydrated salt used =  Mass of the crucible, cover, and contents before heating - Mass of the empty crucible and cover                    

⇒Mass of hydrated salt used =   = 23.54 g – 18.82 g

⇒Mass of hydrated salt used =  = 4.72 g

⇒Mass of dehydrated salt after heating = Mass of the crucible, cover, and contents after heating to constant mass-Mass of the empty crucible and cover

⇒Mass of dehydrated salt after heating = 20.94 g – 18.82 g

⇒Mass of dehydrated salt after heating = 2.12 g

⇒ Mass of water liberated from salt = Mass of hydrated salt used -   Mass of dehydrated salt after heating

⇒  Mass of water liberated from salt = 4.72 g – 2.12 g    

⇒  Mass of water liberated from salt = 2.60 g  

Water % in the hydrated salt is found as;

% water =(mass of water/  mass of hydrated salt)× 100

% water =(2.60/4.72) × 100

% water =55.08 %

Hence the percent of water in the hydrated salt will be 55.08 %

To learn more about the mass, refer to the link.\

https://brainly.com/question/13073862

#SPJ1

The hybrid orbital of this molecule is [tex]sp^3[/tex]. Hence, option C is correct.

Hybridization is defined as the concept of mixing two atomic orbitals to give rise to a new type of hybridized orbitals.

In this compound, [tex]sp^3[/tex] a hybrid orbital makes I-O bonds. Due to [tex]sp^3[/tex]hybridization iodate should have tetrahedral geometry but because of the presence of lone pair of electrons the shape of [tex]IO^{3-}[/tex] the ion is pyramidal.

The hybrid orbital of this molecule is [tex]sp^3[/tex]. Hence, option C is correct.

Learn more about hybridisation here:

https://brainly.com/question/23038117

#SPJ1

The equilibrium constant K for the following reaction at 25°C from standard electrode potentials is Antilog (37.5).

Chemical equilibrium is the condition in the course of a reversible chemical reaction in which no net change in the amounts of reactants and products occurs.

Reduction Half-Reaction

[tex]Fe^{3+}[/tex](aq)+[tex]e^-[/tex] →[tex]Fe^{2+}[/tex](aq)

Standard reduction electrode potentials = +0.77

Oxidation Half-Reaction

Cu(s) = [tex]Cu^{+2}[/tex](aq) + 2[tex]e^-[/tex]

Standard reduction electrode potentials = -0.34

E° cell= E°cathode- E°anode

E° cell= +0.77+0.34

E° cell=1.11

E°cell= 0.0592÷n logK

From the redox reaction equations above, n=2

1.11 V= 0.0592÷2 logK

37.5 =  logK

K= Antilog (37.5)

Hence,  the equilibrium constant K for the following reaction at 25°C from standard electrode potentials is Antilog (37.5).

Learn more about chemical equilibrium here:

https://brainly.com/question/4289021

#SPJ1

Answer:

organic chemistry is chemistry focused on structure and composition, extending to recations and properties of compounds.

often centered around compounds with carbon.

alcohols, amines, and aldehydes are some groups that are studied on organic chemistry

SHORT ANSWER:

a) chemistry focused on the structure qnd composition of compounds

b) alcohols, amines, aldehydes

Explanation:

Organic compounds, which are the compounds associated with life processes, are the subject matter of organic chemistry. Among the numerous types of organic compounds, four major categories are found in all living things: carbohydrates, lipids, proteins, and nucleic acids.

Answer:

It depends on how high you are above sea level

Explanation:

I did an experiment in my Scince class that showed, the less air that is around water will lessen it’s boiling level. We put water in a glass beaker inside of our vacuum chamber, we made a vacuum in he chamber. Making a vacuum is like being on a mountain, the less air the lower the boiling point. The water then began to boil due to the water evaporating. When we reached to maximum vacuum that we could the water started to boil at 61°C. No the water was not very hot, it was just warm water that just so happened to also be boiling, cool right!!! Anyways, we played with dry ice the next day.

Hoped this helped.

Hope I earned your star rating or helpful rating from this.

the air pressure around the experiment is lower than at sea level