I NEED HELPPPPPP ASAP

Answer:

4.031×[tex]10^{23}[/tex]

Explanation:

You first need to calculate the number moles of NO2.  To do this use PV=nRT

STP stands for standard temperature and pressure which is 0 degrees C and 1 atm.

due to that:

P = 1 atm

V = 15 L

R = 0.08206 L*atm/mol*K

T = 273 K

n = unknown moles

solve for n to make the equation n=PV/RT

n=(1atm*15L)/(0.08206 Latm/molK*273K)

n=0.6696 mol of NO2

Then to find the number of molecules we use Avogadro's number which tells us the number of molecules per mol of a molecule or atom.

Avogadro's number is  6.02x10^23 molecules/mol

number of molecules = 0.6696mol × 6.02x10^23 molecules/mol

number of molecules = 4.031×10^23 molecules of NO2

Let me know if anything is not clear or if you get something else in the comments so that we can work it out.

Answer:

2

Explanation:

Nobel gasses are not reactive and are the far right group on the periodic table.  This is because they have a full valence electron shell which is the most stable electron configuration.  Most reactions occur in order for an atom to fill its valence shell and since they already have a full valence shell there is no reason for them to react.

Answer:

the sun would reflect off of the windows causing less heat to travel into the building

Explanation:

Answer:

D and A

Explanation:

D is a Mitochondria (the powerhouse of the cell)

A is a Choroplast (the part that takes in the sun)

Answer:

a phrase that describes how elements what do be stable and non reactive like the noble gas elements are.

longitudinal

all sound waves are longitudinal

Answer:

Fe2O3

Explanation:

Answer:

Fe2O3

This is the chemical formula for iron(iii) oxide.

Answer:

false

Explanation:

Answer:

FALSE ...

Explanation:

However, unlike plants, fungi do not contain the green pigment chlorophyll and therefore are incapable of photosynthesis. That is, they cannot generate their own food — carbohydrates — by using energy from light. This makes them more like animals in terms of their food habits

Answer:

[tex]$Na_2O + H_2O \rightarrow 2NaOH$[/tex]

Explanation:

When solid sodium oxide reacts with water in a room temperature, it forms sodium hydroxide.

The one word equation of the reaction will show or represent the reactants on the left hand side of the arrow and the products on the reaction on the right hand side of the reactants.

Thus the equation of the reaction is :

[tex]$Na_2O(s) + H_2O(l) \rightarrow 2NaOH(aq)$[/tex]

Sodium oxide + water ----[tex]$\rightarrow$[/tex] sodium hydroxide.

The equation for the chemical reaction should be [tex]Na_2O + H_2O \rightarrow 2NaOh[/tex]

At the time when the solid sodium oxide reacted with the water in room temperature so it created the sodium hydroxide.

Here the one-word equation represents that the reactant should be on the left-hand side while on the other hand, the product should be on the right-hand side.

Also, it should be like

Sodium oxide + water ---- sodium hydroxide.

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Answer:

Im pretty sure its none of these

Explanation:

Orbitals are spaces that have a high probability of containing an electron. ... The s sublevel has just one orbital, so can contain 2 electrons max. The p sublevel has 3 orbitals, so can contain 6 electrons max. The d sublevel has 5 orbitals, so can contain 10 electrons max.

Answer:

There are different energy levels in atoms. There are also different orbitals: there is 1s orbital, 3p orbitals, 5d orbitals and 7f orbitals. Not sure about sub levels...

Explanation:

Answer:

Neutrons

Explanation:

let me know if it is right or not:)

Answer:

маликулярная масса ровна  23

Answer:

B. Respiratory System

Answer:

B, Respiratory

Explanation:

Answer:

Concentration of the original [tex]\rm KOH[/tex] solution: approximately [tex]1.05\; \rm mol \cdot dm^{-3}[/tex].

Explanation:

Notice that the concentration of the [tex]\rm HCl[/tex] solution is in the unit [tex]\rm mol\cdot dm^{-3}[/tex]. However, the unit of the two volumes is [tex]\rm cm^{3}[/tex]. Convert the unit of the two volumes to [tex]\rm dm^{3}[/tex] to match the unit of concentration.

[tex]\begin{aligned} V(\mathrm{NaOH}) &= 25.0\; \rm cm^{3} \\ &= 25.0\; \rm cm^{3} \times \frac{1\; \rm dm^{3}}{1000\; \rm cm^{3}} \approx 0.0250\; \rm dm^{3} \end{aligned}[/tex].

[tex]\begin{aligned} V(\mathrm{HCl}) &= 35.0\; \rm cm^{3} \\ &= 35.0\; \rm cm^{3} \times \frac{1\; \rm dm^{3}}{1000\; \rm cm^{3}} \approx 0.0350\; \rm dm^{3} \end{aligned}[/tex].

Calculate the number of moles of [tex]\rm HCl[/tex] molecules in that [tex]0.0350\; \rm dm^{3}[/tex] of [tex]0.75\; \rm mol \cdot dm^{3}[/tex] [tex]\rm HCl\![/tex] solution:

[tex]\begin{aligned}n(\mathrm{HCl}) &= c(\mathrm{HCl}) \cdot V(\mathrm{HCl}) \\ &= 0.00350\; \rm dm^{3} \times 0.75\; \rm mol \cdot dm^{3} \\ &\approx 0.02625\; \rm mol\end{aligned}[/tex].

[tex]\rm HCl[/tex] is a monoprotic acid. In other words, each [tex]\rm HCl\![/tex] would release up to one proton [tex]\rm H^{+}[/tex].

On the other hand, [tex]\rm KOH[/tex] is a monoprotic base. Each [tex]\rm KOH\![/tex] formula unit would react with up to one [tex]\rm H^{+}[/tex].

Hence, [tex]\rm HCl[/tex] molecules and [tex]\rm KOH\![/tex] formula units would react at a one-to-one ratio.

[tex]{\rm HCl}\, (aq) + {\rm NaOH}\, (aq) \to {\rm NaCl}\, (aq) + {\rm H_2O}\, (l)[/tex].

Therefore, that [tex]0.02625\; \rm mol[/tex] of [tex]\rm HCl[/tex] molecules would neutralize exactly the same number of [tex]\rm NaOH[/tex] formula units. That is: [tex]n(\mathrm{NaOH}) = 0.02625\; \rm mol[/tex].

Calculate the concentration of a [tex]\rm NaOH[/tex] solution where [tex]V(\mathrm{NaOH}) = 0.0250\; \rm dm^{3}[/tex] and [tex]n(\mathrm{NaOH}) = 0.02625\; \rm mol[/tex]:

[tex]\begin{aligned}c(\mathrm{NaOH}) &= \frac{n(\mathrm{NaOH})}{V(\mathrm{NaOH})} \\ &= \frac{0.02625\; \rm mol}{0.0250\; \rm dm^{3}}\approx 1.05\; \rm mol \cdot dm^{-3}\end{aligned}[/tex].

Answer:

True

Explanation:

Whenever something loses thermal energy, it contracts and becomes smaller.

Answer: it might be true

Explanation:

Answer:

actually there are 6 of them

Explanation:

heres the list:

They are beryllium, magnesium, calcium, strontium, barium, and radium.

hope it helpssss :)

Answer/Explanation:

Alkaline earth metals are similar to Alkali Metals, but they tend to to be harder, denser, and less reactive. However it is too reactive to be found in nature. It is commonly found in batteries, fireworks, flashlights, and cameras. It has Valence Electrons of 2 and the elements in this category are:

Answer:

CuSO4(aq)

Explanation:

The aqueous for of CuSO₄ is an electrolyte and it will conduct electricity.

CuSO₄ is an ionic substance and in solid state, it will not have the ability to conduct electricity.

Answer:

the surface may become etheir scratchy and soft and that the surface may also be come heated up due to friction

When a surface is experiencing friction with another surface, the surface may become either scratchy and soft and that the surface may also be come heated up due to friction.

When a surface is experiencing friction with another surface, the surface may become either scratchy and soft and that the surface may also be come heated up due to friction.

Projectile motion is a type of motion in which a object is thrown from the surface earth at some angle it will take projectile projection .

In above question a man thrown a object 14 m/sec an it will moves 2 meter.

Then

vsinθ×t−1/2×gt^2=25

where v = initial velocity in m/sec

t = time in sec

g = acceleration due to gravity

14sinθ×1−5×12=25

14sin=30

sin=30/14

sinθ>2 not possible

vsinθt−1/2×gt^2=2

14×sinθ−5=2

14xsinθ=7

Sinθ=7/14

Sinθ=1/2

θ=30 degree

Therefore, When a surface is experiencing friction with another surface, the surface may become either scratchy and soft and that the surface may also be come heated up due to friction.

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Answer:

A

Explanation:

bc inorganic compoud refers to all compound that do not contain carbons.

Answer:

yes I do

But I can't see the question very well

Explanation:

Answer:

In a polar covalent bond, the more electronegative atom pulls electrons closer and gains a slightly negative charge, while the less electronegative atom has a slightly positive charge.

Explanation:

The covalent bond is the chemical bond between two atoms where electrons are shared. This makes the atoms behave as a unit, which we call a molecule. Atoms interact with each other through the outermost electrons forming bonds.

In other words, the covalent bond is formed by sharing a pair of electrons between the two atoms, one coming from each atom. The shared pair of electrons is common to the two atoms and holds them together. So molecules are formed: small groups of atoms linked together by covalent bonds.

In covalent bonds a dipole forms. The atom with the highest electronegativity attracts electrons towards itself, forming a negative dipole around it since the electrons have a negative charge. In the atom with lower electronegativity, the dipole formed is positively charged, since it partially gives up its electrons.

This is, in a polar covalent bond, the more electronegative atom pulls electrons closer and gains a slightly negative charge, while the less electronegative atom has a slightly positive charge.

Answer:

Basee is the answer hope its write xd

Answer:

B: Base

Explanation:

An acid will increase the concentration of hydrogen (H+) ions in a solution, and a base would increase the concentration of hydroxide (OH–) ions in a solution. So, Base is the answer.  :)

Answer:

C

Explanation:

Just look at the reactants.

2AgCl + BaBr2

The first reactant is made of 2 elements.

The second reactant is made of 2 elements.

It can't be a decomposition. At this level there is only one reactant made of 2 elements. Something like

2MgO ===> 2Mg + O2

is a decomposition.  One compound breaking down into 2 elements Mg and O.

It can't be a combustion. One of the reactants in a combustion is oxygen. Those equations look like

C3H8 + 5O2 ==> 3CO2 + 4H2O

That would be what a combustion looks like

It can't be a single replacement. They look like

Mg + CuO ===> Cu + MgO

There are elements on both sides of the reaction.

that leaves a double replacement which I wrote about how you distinguish it.

Answer:

c

Explanation:

Answer:

C

Explanation:

When a hammer strikes and exerts force on a nail, the nail exerts an equal force back on the hammer. Option C. This is further explained below.

Generally, According to Newton's third law, when two bodies contact, they apply forces to each other that are equal in magnitude and opposing in direction.

In conclusion, Newton’s third law of motion certifies that the nail exerts an equal force back on the hammer.

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Answer:

D)  single replacement

Explanation:

Given reaction:

         Mg       +           2HCl      →      MgCl₂        +        H₂

The reaction shown above is a single displacement reaction.

In a single displacement reaction, a more reactive atom displaces another from a given compound.

The comparison here is between Mg and H.

On the activity series, Mg is higher and more reactive, it will displace H from the solution of HCl. This

This reaction type is called a single replacement reaction.