Which is the correct Lewis dot structure of NH2-?

Answer: The mass of lead (II) nitrate required is 74.52 g

Explanation:

The number of moles is defined as the ratio of the mass of a substance to its molar mass.

The equation used is:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)

Given mass of lead (II) chloride = 62.6 g

Molar mass of lead (II) chloride = 278.1 g/mol

Plugging values in equation 1:

[tex]\text{Moles of lead (II) chloride}=\frac{62.6g}{278.1g/mol}=0.225 mol[/tex]

The chemical equation for the reaction of lead (II) chloride and sodium nitrate follows:

[tex]Pb(NO_3)_2+2NaCl\rightarrow PbCl_2+2NaNO_3[/tex]

By the stoichiometry of the reaction:

1 mole of lead (II) chloride is produced from 1 mole of lead (II) nitrate

Then, 0.225 moles of lead (II) chloride will react with = [tex]\frac{1}{1}\times 0.225=0.225mol[/tex] of lead(II) nitrate

Molar mass of lead (II) nitrate = 331.2 g/mol

Plugging values in equation 1:

[tex]\text{Mass of lead (II) nitrate}=(0.225mol\times 331.2g/mol)=74.52g[/tex]

Hence, the mass of lead (II) nitrate required is 74.52 g

Answer:

4000mL

Explanation:

Using the combined gas law equation as follows:

P1V1/T1 = P2V2/T2

Where;

P1 = initial pressure (atm)

P2 = final pressure (atm)

V1 = initial volume (mL)

V2 = final volume (mL)

T1 = initial temperature (K)

T2 = final temperature (K)

According to the information given in this question:

V1 = 1000mL

T1 = 20K

P1 = 1.0atm

V2 = ?

P2 = 0.5atm

T2 = 40K

Using P1V1/T1 = P2V2/T2

1 × 1000/20 = 0.5 × V2/40

1000/20 = 0.5V2/40

50 = 0.5V2/40

50 × 40 = 0.5V2

2000 = 0.5V2

V2 = 2000/0.5

V2 = 4000mL

Answer:

In chemistry, neutralization or neutralisation is a chemical reaction in which acid and a base react quantitatively with each other. In a reaction in water, neutralization results in there being no excess of hydrogen or hydroxide ions present in the solution.Neutralization reactions are the reaction between acid and base. The products formed are water and salt. It is called so because the acid and base neutralize each other to form water and salt.Hint: The neutralization reaction is the one in which an acid reacts with an equimolar amount of base to give salt and water. The example could be a reaction between any strong acid and a base. The sodium chloride formed is a result of neutralization reaction.

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Answer: 0.0016 moles of copper are present in copper gluconate

Explanation:

The number of moles is defined as the ratio of the mass of a substance to its molar mass.

The equation used is:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)

Given mass of copper = 0.1 g

Molar mass of copper = 63.55 g/mol

Plugging values in equation 1:

[tex]\text{Moles of copper}=\frac{0.1g}{63.55g/mol}=0.0016 mol[/tex]

Hence, 0.0016 moles of copper are present in copper gluconate

Answer:

External stimulus of thirst

Answer:

your answer is:         the external stimulus of thirst

Explanation:

I took the test :)) hope this helps!!!!!!

put the glass lid on and turn or turn down the heat

Answer:

The energy absorbed in the first move is greater than the energy released in the second move

Explanation:

Electrons require (absorb) energy to move to a higher energy level when there is a large external heat source, the presence of an electric field or by colliding with other electrons

And the amount of energy absorbed by the electron is exactly equal to the change in the energy state between the initial energy level of the electron and the destination energy level

Therefore, given that the energy level of the electron at level 2 is higher than the energy level of the electron when at level 1, we have;

The difference in the energy level between level 4 and level 1 is greater than the difference in the energy level between level 4 and level 2 and more energy is absorbed and therefore, released when the electron moves from level 1 to level 4 than when the electron drops from level 4 to level 2.

The most likely result is that 'the energy absorbed in the first move is greater than the energy released in the second move'.

Answer:

4.65 g x 1 mol/4.0026 g/mol = 1.162 mol helium

Explanation:

Fluorine has the highest electronegativity in comparison to other elements therefore, the F atom attracts electrons most strongly.

The electronegativity of an atom measures the tendency of an element to attract the bonded electrons pairs towards itself. The electronegativity of an atom is determined with respect to another bonded atom.

Electronegativity can be described as a chemical property of an atom or a functional group to attract electrons toward itself. The electronegativity of an atom depends on the atomic number and the distance of valence electrons from the charged nuclei.

When two different atoms are bonded through a bond. More electronegative will attract the electron density of the bond towards itself.

As we know, the electronegativity decreases as we move down the group in the periodic table. Fluorine is the most electronegative element in the periodic table therefore, Fluorine (F) will attract the electrons toward it most strongly.

Learn more about electronegativity, here:

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Answer:

Explanation:

a ) If N₂(g) and 3H₂(g) is added to the system , 2 moles of additional  ammonia will be produced .

b ) If pressure is decreased , less amount of ammonia will be formed, because forward reaction reduces the pressure. So, reaction will take place in reverse direction.

c ) Keq = [ NH₃ ] ² / [ N₂ ] [ H₂]³

d ) Substituting the given values in the equation ,

Keq = [ 6M ] ² / [ 3M] [ 4M]³

= 36 / 3 x 64 M⁻²

= 18.75 x 10⁻² M⁻² .

Taking into account the molar mass of each elemente and ammonia, the correct answer is the first option: the percentage composition of each element in ammonia, NH₃ is 82.35% N; 17.65% H

First of all, molar mass is the mass of one mole of a substance, which can be an element or a compound. In the case of a compound, it is calculated by adding the atomic masses of the atoms that make up the molecule.

In this case, being the atomic mass of N equal to 14 and the atomic mass of H equal to 1, the molar mass of NH₃ is calculated as:

NH₃= 14 + 3* 1= 17

Now, to obtain the percentage composition of each element, you must divide each individual atom with the mass of ammonia and multiply by 100 to obtain the percentage:

N: [tex]\frac{14}{17} x100[/tex]

H: [tex]\frac{1x3}{17} x100[/tex] In this case, the atomic mass of hydrogen H is multiplied by 3 because 3 hydrogens are present in ammonia.

Solving:

N: [tex]\frac{14}{17} x100[/tex]= 0.8235×100= 82.35 %

H: [tex]\frac{3}{17} x100[/tex]= 0.1765×100= 17.65 %

Finally, the correct answer is the first option: the percentage composition of each element in ammonia, NH₃ is 82.35% N; 17.65% H

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Answer:

Tussar silk

Charmeuse

Explanation:

Hope this helps! :)

Answer:

As the kinetic energy of the gaseous solute increases, its molecules have a greater tendency to escape the attraction of the solvent molecules and return to the gas phase. Therefore, the solubility of a gas decreases as the temperature increases.

Explanation:

As the kinetic energy of the gaseous solute increases, its molecules have a greater tendency to escape the attraction of the solvent molecules and return to the gas phase. Therefore, the solubility of a gas decreases as the temperature increases

Answer:

1.89 nol Cu(NO3)2

Explanation:

if you calculate it it will be 1.89

Answer:

Because metal can not decompose!

Answer:

Contrasting Nuclear Fission and Nuclear Fusion

Nuclear FissionByproducts of the reaction: Fission produces many highly radioactive particles.Conditions: Critical mass of the substance and high-speed neutrons are required.Energy Requirement: Takes little energy to split two atoms in a fission Explanation:

Answer:

d. pOH = 12 => pH = 14 - 10 = 2 => most acidic

Explanation:

pH = -log[H⁺] => [H⁺] = 10^-pH

By definition, if ...

[H⁺] > 10⁻⁷ > [OH⁻] => pH < -log(10⁻⁷) < 7 => pOH > 14 - 7 > 7 => acidic solution

[H⁺] = 10⁻⁷ = [OH⁻]  => pH = -log(10⁻⁷) = 7 => pOH = 14 - 7 = 7 => neutral solution

[H⁺] < 10⁻⁷ < [OH⁻]  => pH > -log(10⁻⁷) > 7 => pOH < 14 - 7 < 7 => basic solution

∴ From most basic to most acidic ...

a. pH = 12 => most basic

b. pOH = 5 => pH = 14 - 5 = 9

c. [H⁺] = 1 x 10⁻⁸ => pH = -log(10⁻⁸) = -(-8) = 8

d. pOH = 12 => pH = 14 - 10 = 2 => most acidic

Answer: A

Explanation:

the melting point or boiling point of a substance at a specific pressure

Answer:

75.9 grams of salt

Explanation:

The reaction is the following:  

2Na(s) + Cl₂(g) → 2NaCl(s)   (1)

We have:

m(Na): the mass of sodium = 30 g

V(Cl₂): the volume of the chlorine gas at STP = 60 L

So, to find the mass of NaCl we need to calculate the number of moles of Na and Cl₂.

[tex] n_{Na} = \frac{m}{A_{r}} = \frac{30 g}{22.99 g/mol} = 1.30 moles [/tex]

The number of moles of Cl₂ can be found by the Ideal gas law equation:

[tex] PV = n_{Cl_{2}}RT [/tex]

Where:

P: is the pressure = 1 atm (at STP)

R: is the gas constant = 0.082 L*atm/(K*mol)

T: is the temperature = 273 K (at STP)

[tex] n_{Cl_{2}} = \frac{PV}{RT} = \frac{1 atm*60 L}{0.082 L*atm/(K*mol)*273 K} = 2.68 moles [/tex]

Now we need to find the limiting reactant. From the stoichiometric relation between Na and Cl₂ (equation 1), we have that 2 moles of Na react with 1 mol of Cl₂, so:

[tex] n_{Na} = \frac{2 moles Na}{1 mol Cl_{2}}*2.68 moles Cl_{2} = 5.36 moles [/tex]

Since we have 1.30 moles of Na, the limiting reactant is Na.  

Finally, we can find the number of moles of NaCl and its mass.

[tex] n_{NaCl} = n_{Na} = 1.30 moles [/tex]

[tex] m_{NaCl} = n_{NaCl}*M = 1.30 moles*58.44 g/mol = 75.9 g [/tex]

Therefore, would be formed 75.9 grams of salt.

I hope it helps you!                

Answer:

potential and chemical

Explanation:

Answer:

Gold and pyrite both have a brilliant metallic luster, but are different tones of yellow. Gold is golden to silvery yellow, whereas pyrite is a pale to medium brassy yellow that sometimes tarnishes.

Explanation:

Answer:

sry, dk

Explanation:

Answer:

your awnser would be 72.1

Explanation:

hope this helps have a good day :]

Answer:

A. Fusion

Explanation:

Answer:

your simpal answer is 177.32

Answer:

3132 is the answer

Explanation:

3BaCl2 + Al2S3 → 3BaS + 2AlCl3

Answer:

Explanation:

Hope this helps u !!

Answer:

2.34 %

Explanation:

Since the density of the Jello, ρ = 1.14 g/mL and ρ = m/v where m = mass of jello and v = volume of jello = 475 mL.

So, m = ρv

substituting the values of the variables into the equation, we have

m = ρv

m = 1.14 g/mL × 475 mL = 541.5 g

Since we have 13 g of sugar in the jello, the total mass present is 13 g + 541.5 g = 554.5 g

So, the percentage by mass of sugar present % m/m = mass of sugar present/total mass × 100 %

= 13 g/554.5 g × 100 %

= 0.0234 × 100 %

= 2.34 %

So, the percentage by mass of sugar present % m/m = 2.34 %