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Answer:

Hydroxide concentration of the sample is 1.3x10⁻⁶M

Explanation:

The equilibrium constant of water, Kw, is:

H₂O(l) ⇄ H⁺(aq) + OH⁻(aq)

Kw is defined as:

Kw = 1.7x10⁻¹² = [H⁺] [OH⁻]

As the sample is of pure water, both H⁺ and OH⁻ ions have the same concentration because come from the same equilibrium, that is:

[H⁺] = [OH⁻]

We can write the Kw expression:

1.7x10⁻¹² = [OH⁻] [OH⁻]

1.7x10⁻¹² = [OH⁻]²

1.3x10⁻⁶M = [OH⁻]

Answer:

21 molecules of water.

Explanation:

The polymerization of a 22-monomer long cellulose molecule will require 21 molecules of water. This is because the polymer bond is formed when the -OH group from the 1st monomer of the glucose unit and the H group from the 2nd monomer gets removed as a water molecule. This process is termed to be a condensation reaction.

Answer:

A, D, E

Explanation:

a. "A dog panting to stay cool on a hot day" is a mechanism the dog employs to maintain it's body temperature. This is homeostasis.

d. "A bear hibernates in order to reduce their metabolism and conserve energy during the winter" is also all about keeping the internal condition of the bear's body constant. So this is also an example of homeostasis.

e. The lizard trying to keep regulate it's body temperature is also part of homeostasis.

Answer: Its all of them

Explanation: I just took the test

Answer:

this question is badly formatted. CO2

Explanation:

the answer is CO2 because C and O are both anions/nonmetals. the other examples contain a cation/metal, so they're ionic compounds

Answer:

- C6H12O6 is not an empirical formula because it can be simplified to CH2O.

- CaCO3 is an empirical formula as well as molecular formula because it has been simplified up to the smallest subscript per atom.

- NaMnO4 is an empirical formula as well as molecular formula because it has been simplified up to the smallest subscript per atom.

- Ba3(PO4)2 is an empirical formula as well as molecular formula because it has been simplified up to the smallest subscript per atom.

- K2C2O4 is not an empirical formula because it can be simplified to KCO2.

Explanation:

Hello!

In this case, since the empirical formulas are referred to those formulas that have been simplified up to the smallest whole number for each subscript per atom, we can see that:

- C6H12O6 is not an empirical formula because it can be simplified to CH2O.

- CaCO3 is an empirical formula as well as molecular formula because it has been simplified up to the smallest subscript per atom.

- NaMnO4 is an empirical formula as well as molecular formula because it has been simplified up to the smallest subscript per atom.

- Ba3(PO4)2 is an empirical formula as well as molecular formula because it has been simplified up to the smallest subscript per atom.

- K2C2O4 is not an empirical formula because it can be simplified to KCO2.

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Answer:

mercury (I) silicate

Explanation:

Answer:

[tex]m_{N_2}=56.04 gN_2[/tex]

Explanation:

Hello!

In this case, since nitrogen diatomic gas is a molecule that has the following molar mass:

[tex]M_{N_2}=14.01*2\\\\M_{N_2}=28.02g/mol[/tex]

Thus, since we have two moles of this molecule, we can compute the referred mass as shown below:

[tex]m_{N_2}=2molN_2*\frac{28.02gN_2}{1molN_2}\\\\m_{N_2}=56.04 gN_2[/tex]

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Explanation:

Used to separate one reactant or product from another

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Answer: 55.56 moles of MgO

Explanation:

1 mole = avogadro number

if 6.21x10^25 atoms then molecules of MgO (equal numbers of Mg and O atoms)

= 0.5*6.21x10^25 = 3.105 molecules of MgO

So moles of MgO = 0.5*6.21*10^25/avogadro number = 55.56

Answer:

i think it is 1.27 x1024

Explanation:

i don't really know though

Answer:

(160/28+48)=(160/76)*6.022x10²³

Answer:

[tex]V=202mL[/tex]

Explanation:

Hello!

In this case, considering we have a 5.11-molar solution (5.11 M) that contains 175. g of silver nitrate, we first need to compute the moles of solute as its molar mass is 169.87 g/mol:

[tex]n=175g*\frac{1mol}{169.87 g} =1.03mol[/tex]

Next, since the definition of molarity is moles over volume:

[tex]M=\frac{n}{V}[/tex]

We solve for the volume and plug in the molarity and moles as shown below:

[tex]V=\frac{n}{M} =\frac{1.03mol}{5.11mol/L}\\\\V =0.202L[/tex]

However, as it is needed in milliliters, we convert the L to mL:

[tex]V=0.202L*\frac{1000mL}{1L}\\\\V=202mL[/tex]

Best regards!

Answer:

11 molecules of CH4.

23 atoms of C is the leftover.

Explanation:

Hello!

In this case, for the formation of methane:

[tex]C+2H_2\rightarrow CH_4[/tex]

We can see there is an excess of carbon based on their stoichiometry, because the needed amount of hydrogen gas molecules would be:

[tex]molecules _{H_2}=34atomC*\frac{2molec\ H_2}{1atomC} =68molec\ H_2[/tex]

Thus, the formed molecules of methane are computed below:

[tex]molec\ CH_4=22molec\ H_2 *\frac{1molec\ CH_4}{2molmolec\ H_2} \\\\molec\ CH_4=11molec\ CH_4[/tex]

In such a way, the leftover of carbon atoms are:

[tex]atoms \ C^{left over}=34-22molec\ H_2*\frac{1atoms C}{2molec\ H_2} \\\\atoms \ C^{left over}=23 atoms C[/tex]

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Answer:

See explanation and images attached

Explanation:

The complete question his shown in the image attached to this answer.

This reaction is a substitution reaction. We identify it as a substitution reaction because one specie replaced another in the substrate.

The organic product and inorganic products were also shown in the image. The bond was breakage is a hetereolytic fission since the two electrons of the bond reside on only one of the species.

Answer:

Primary

Explanation:

Succession is a series of progressive changes in the composition of an ecological community over time. In primary succession, newly exposed or newly formed rock is colonized by living things for the first time.

C₆H₁₂O₆ has the greatest molar mass (180 g/mol)

Given

Compounds of A. H2O B. C6H12O6 C. HNO3 D. C2H6

Required

The greatest molar mass

Solution

The molar mass(molecular mass-formula mass) of a compound is the sum of the relative atomic mass (Ar) of the constituent elements of the compound

A. H₂O : 2.1+16 = 18 g/mol

B. C₆H₁₂O₆ : 6.12+12.1+6.16=180 g/mol

C. HNO₃ : 1.1+1.14+3.16=63 g/mol

D. C₂H₆ : 2.12+6.1 = 30 g/mol

Answer:

See explanation

Explanation:

Let the rate of diffusion of the unknown gas be x

Let the rate of diffusion of nitrogen be y

Let molecular mass of unknown gas be MX

Let molecular mass of nitrogen be My

Hence;

x/y = √My/MX

0.936/1 = √28/MX

(0.936/1)^2= 28/MX

MX= 28/0.876096

MX= 32 g/mol

MX is O2 gas

Answer:

The Saffir-Simpson Hurricane Wind Scale is a 1 to 5 rating based on a hurricane's sustained wind speed. This scale estimates potential property damage. Hurricanes reaching Category 3 and higher are considered major hurricanes because of their potential for significant loss of life and damage.

Explanation:

Please mark me as brilliant and thank you.

Answer:

ptic fiber communication and satellite communication are the leading technologies which are revolutionizing the world of telecommunications. Both technologies have their advantages and limitations which make them suitable for certain type of applications. This article will provide an overview of optic fiber and satellite communication technologies and present a comparison of the features and related issues.

Optic Fiber Communication

Optic Fiber communication transmits information by sending pulses of light (using laser) through an optic fiber. The low signal loss in optic fibers and high data rate of transmission systems, allow signals with high data rates (exceeding several Gbps) to travel over long distances (more than 100 km) without a need of repeater or amplifier. Moreover, using wavelength division multiplexing (WDM) allows a single fiber to carry multiple signals (upto 10 different signals) of multi-Gbps transmissions. Optic Fiber communication offers extremely high bandwidth, immunity to electromagnetic interference, non-existent delays and immunity from interception by external means. In the 1980s and 1990s, the continents were linked together using undersea optic fiber bringing about a paradigm shift in the global telecommunications.

These advancements in optic fiber communication has resulted in decrease of satellite communications for several types of communications. For instance, transmission between fixed locations or point-to-point communications, where large bandwidths are required (such as transoceanic telephone systems) are made through optic fiber instead of using satellite communication. Optic Fiber communication is also used to transmit telephone signals, Internet communication, LAN (Gigabit LAN) and cable television signals.

Satellite Communication

Satellite communications use artificial satellites as relays between a transmitter and a receiver at different locations on Earth. Satellite systems allow users to bypass typical carrier offices and to broadcast information to multiple locations. Communications satellites are used for radio, TV, telephone, Internet, military and other applications. There are more than 2,000 satellites around Earth’s orbit, being used for communication by both government and private organizations.

Communication Satellites are LOS (line-of-sight) microwave systems with a repeater. These satellites rotate around the earth with the speed of earth and are known as geostationary satellites. The limitations of antenna size also limits focusing capability making the coverage for a single satellite transmitter very large. This makes satellite communication ideal for TV and radio services as the signal has to flow from a single point to many points in a single direction. The large distance of satellites from the earth (about 22,300 miles) results in delays which adversely effects two-way communication like mobile conversations. Low earth orbit satellites can be used for two-way mobile communication because less power is required to reach those satellites.

Explanation:

Answer:

0.5195 liters of water

Explanation:

First we convert 15.4 grams of barium sulfide (BaS) into moles, using its molar mass:

Then we calculate the required volume of water, using the definition of molarity:

Answer:

P.E for the 4kg bowling ball held 2.5 meters above head is 100j, while the other is 60j so the 4kg ball has more potential energy

Answer:

a

Explanation:

its too much of a solid to be broken down

The substance can not be broken down by a chemical change is A)magnesium.

substance can be regarded as a  particular kind of matter which posses a uniform properties.

Therefore, during a chemical change all the given substance can be broken down because they are compounds, but magnesium is an element which cannot be broken down.

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Answer: A physical property that will be the same regardless of the amount of matter. Extensive Properties:  A physical property that will change if the amount of matter changes.

2.49 × 10⁻¹² moles Pb

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Atomic Structure

Step 1: Define

1.50 × 10¹² atoms Pb

Step 2: Identify Conversions

Avogadro's Number

Step 3: Convert

Step 4: Check

Follow sig fig rules and round. We are given 3 sig figs.

2.49087 × 10⁻¹² moles Pb ≈ 2.49 × 10⁻¹² moles Pb

Answer:

A. 20.5 atm

Explanation:

Using the formula Pv=.nRt

Answer:

PV=nRT

P(56.4)=45.3×0.08206×310.5

P=1154.227/56.4

=20.4650

Approximately 20.5 then A is the answer

Answer:148.31 Grams per mol

Explanation: It has been a long time since I took chemistry.

I believe you add up all the elements molar mass.

magnesium nitrate is Mg(NO3)2 so you add

MG  24.30

N 14.01 * 2 = 28.01

O 16.00 * 6 = 96.00

total is 148.31 grams per mol

I hope this helps.  

The molar mass of magnesium nitrate is 148.31 grams per mol.

The term molar mass is defined as the ratio between the mass and the amount of substance of any sample of the known compound. A mole of any substance is 6.022 × 10²³ molecules.

1 mole = 6.022 × 10²³ elementary entities.

The molar mass of a substance is calculated by adding the quality atomic masses in g/mol of the constituent atoms. Molar mass is represented by the symbol "M".

For calculating molar mass of magnesium nitrate is Mg(NO3)2

Mg =  24.30

Nitrogen = 14.01 × 2

= 28.01

Oxygen = 16.00 × 6

= 96.00

Therefore, molar mass of magnesium nitrate is Mg(NO3)2

=  24.30 + 28.01 + 96.00

=  148.31 grams per mol.

Thus, The molar mass of magnesium nitrate is 148.31 grams per mol.

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Answer and Explanation:

The balanced chemical equations are as follows:

The chemical formula of oxalic is  [tex]H_2C_2O_4[/tex]

In the case when oxalic acts reacted with the water so here the oxalic acid eliminates one proton that leads to the development of mono acids

After that, the second step derives that when oxalic acid is in aqueous solution eliminates other proton so it represent the polyprotic acid

Now the chemical equations are as follows:

Elimination of one proton

[tex]H_2C_2O_4(aq)+H_2O(l) \rightarrow H_2C_2O_4^-(aq) + H_3O^+(aq)[/tex]

Now the elimination of other proton

[tex]HC_2O_4^-(aq)+H_2O(l) \rightarrow C_2O_4^2^-(aq) + H_3O^+(aq)[/tex]