From this value, and assuming that air contains only molecular nitrogen and molecular oxygen gases, calculate the mass percent of N2 and of O2 in air.

Answer:

6.2 × 10^-2

Explanation:

Given the reaction:

------------2N2O(g) N2H4(g) <---> 3N2(g) 2H2O(g)

Initial: N2O = 0.1, N2H4 = 0.25-- 0 - - - - - 0

Then: N20 = -2x, N2H4= - x - - - +3x, +2x

Equ : 0.1 - 2x ; 0.25 - x ; +3x ; +2x

At equilibrium :

Add both:

N2O = 0.1 - 2x ;

N2H4 = 0.25 - x;

3N2 = 3x

2H2O = 2x

Moles of N2O at equilibrium = 0.059

Then;

0.1 - 2x = 0.059

-2x = 0.059 - 0.1

-2x = - 0.041

x = 0.041 / 2

x = 0.0205

Moles of N2 present at equilibrium ;

3N2 = 3x

3N2 = 3(0.0205)

= 0.0615

= 0.062 = 6.2 × 10^-2

Answer:

229%

Explanation:

The equation of the reaction is;

4Al(s) + 3O2(g) ----> 2Al2O3(s)

We must first determine the limiting reactant;

Number of moles of Al2O3 produced = mass/molar mass = 72.4g/101.96 g/mol = 0.71 moles

For Al

Number of moles reacted = mass/molar mass = 49.2g/27 g/mol = 1.8 moles

If 4 moles of Al yields 0.71 moles of Al2O3

1.8 moles of Al will yield 1.8 × 0.71/4 = 0.32 moles of Al2O3

For O2

Number of moles reacted = mass/molar mass = 42.6g/32g/mol = 1.33 moles

If 3 moles of O2 yields 0.71 moles of Al2O3

1.33 moles of O2 will yield 1.33 × 0.71/3 = 0.31 moles of Al2O3

Oxygen is the limiting reactant.

% yield = actual yield/ theoretical yield × 100/1

% yield = 0.71 moles/0.31 moles × 100

% yield = 229%

Answer:

The Earth is divided into two halves by the prime meridian, forming two half spheres divided vertically. The Earth is also divided into two halves by the equator, creating two half spheres divided horizontally.

Explanation:

I took it on edge ( :

Answer:

two of them are chemical changes

Explanation:

1.) the copper roof turns green over time: it forms a new substance which is the green deposit known as verdigris .

2.) baking soda is dissolved in vinegar and bubbles form: it forms a new substance which is carbon dioxide gas.

   I hope it helps:)

Answer:

Electrons occupy orbitals with the lowest energy first.

Explanation:

The Aufbau Principle states that electrons will fill the atomic orbitals with the lowest energy levels first, before occupying others with higher energy levels.

For example, electrons will fill the 1s orbital before filling the 2s orbital.

Answer:

It is Filled sublevels are more stable than partially filled sublevels.

Explanation:

Just took the test and this was right.

Answer:

B. S° > 0, ?H° < 0.

Explanation:

Expression for change in free energy is

     ΔG = ΔH - TΔS

For a reaction to be spontaneous , ΔG should be negative . When we watch the relation above , we find that for  ΔG will be negative at any temperature , if ΔH is negative and  ΔS is positive . Then both the terms on the right hand side will be negative and then   ΔG will become negative.

So option B is correct .

Answer:

FCC.

Explanation:

Hello,

In this case, since the density is defined as:

[tex]\rho =\frac{n*M}{Vc*N_A}[/tex]

Whereas n accounts for the number of atoms per units cell (2 for BCC and 4 for FCC), M the atomic mass of the element, Vc the volume of the cell and NA the Avogadro's number. Thus, for both BCC and FCC, the volume of the cell is:

[tex]Vc_{BCC}=(\frac{4r}{\sqrt{3} } )^3=(\frac{4*0.1345x10^{-7}cm}{\sqrt{3} } )^3=2.997x10^{-23}cm^3\\\\Vc_{FCC}=(2\sqrt{2}r)^{3} =(2\sqrt{2} *0.1345x10^{-7}cm)^3=5.506x10^{-23}cm^3[/tex]

Hence, we compute the density for each crystal structure:

[tex]\rho _{BCC}=\frac{n_{BCC}*M}{Vc_{BCC}*N_A}=\frac{2*102.9g/mol}{2.337x10^{-23}cm^3*6.022x10^{23}/mol} =14.62g/cm^3\\\\\rho _{FCC}=\frac{n_{FCC}*M}{Vc_{FCC}*N_A}=\frac{4*102.9g/mol}{5.506x10^{-23}cm^3*6.022x10^{23}/mol} =12.41g/cm^3[/tex]

Therefore, since the density computed as a FCC crystal structure matches with the actual density, we conclude rhodium has a FCC crystal structure.

Regards.

Answer:

[H₂SO₄] = 4.56 M

Explanation:

35.2 % by mass of H₂SO₄ means that in 100 g of solution, we have 35.2 grams of solute.

We convert the mass of solute to moles.

35.2 g / 98 g/mol = 0.359 moles

These moles are contained in 100 g of solution, so we use density to determine the volume.

1.27 g/mL = 100 g / volume

Volume = 100 g / 1.27 g/mL = 78.74 mL

Molarity is mmol /mL (either we can say, moles in 1L of solution).

We convert the moles to mmoles → 0.359 mol . 1000 = 359 mmoles

M = 359 mmoles/74.74 mL = 4.56 M

Answer:

Explanation:

The pH of the solution can be found by using the formula

pH = - log [H+]

From the question

[H+] = 10^-5 M

Substitute the value into the above formula and solve for the pH

That's

[tex]pH = - log( {10}^{ - 5} ) [/tex]

We have the final answer as

pH = 5

Hope this helps you

Answer:

A

Explanation:

The measurement represents the largest quantity among the given options is 47.3 mg Hence, Option (A) is correct.

An arithmetical multiplier for converting a quantity expressed in one set of units into an equivalent expressed in another.

Therefore comparing all the four options it can be concluded that,The measurement represents the largest quantity among the given options is 47.3 mg Hence, Option (A) is correct.

Learn more about measurement here ;

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Answer:1.6989

Explanation:

The pH of the solution prepared by mixing NaOH and [tex]\rm HNO_3[/tex] has been 1.69.

The moles of NaOH can be given by:

Moles = Molarity × Volume (L)

Moles of NaOH = 0.002 mol

Moles of [tex]\rm HNO_3[/tex] = 0.003 mol

Since,  [tex]\rm HNO_3[/tex] has been remaining in the solution after neutralization, the moles of [tex]\rm HNO_3[/tex] has been :

[tex]\rm HNO_3[/tex] = 0.003 - 0.002 mol

[tex]\rm HNO_3[/tex] = 0.001 mol.

The moles of [tex]\rm HNO_3[/tex] has been equivalent to the moles of hydrogen ion.

The hydrogen ion has been 0.001 mol.

The concentration of Hydrogen ions can be given by:

Hydrogen ion concentration = [tex]\rm \dfrac{Moles}{Volume(L)}[/tex]

Hydrogen ion concentration = [tex]\rm \dfrac{0.001}{0.03\;+\;0.02}[/tex]

Hydrogen ion concentration = 0.02 M.

pH can be defined as the negative log of the hydrogen ion concentration.

pH = - log ([tex]\rm H^+[/tex])

pH = - log (0.02)

pH = 1.69

The pH of the solution prepared by mixing NaOH and [tex]\rm HNO_3[/tex] has been 1.69.

For more information about the pH of the solution, refer to the link:

https://brainly.com/question/4975103

Explanation:

Chromatography = It is a method in which a drop of mixture is spot is spotted at one of the end of the paper. After some time whenever it gets dried, it is then dipped into solvent without toushing the spot. As a result the mixtures gets separated.

Hence, the correct option is (c) "The separation of substances in a mixture by differences in their attraction to a substance over which they are passed"

Answer:

Sebacic acid is a naturally occurring dicarboxylic acid with the formula (CH2)8(CO2H)2. It is a white flake or powdered solid. Sebaceus is Latin for tallow candle, sebum is Latin for tallow, and refers to its use in the manufacture of candles.

Explanation:

pls mark as brainliest!!!!!

Answer:

Keep a close eye on her in case she starts giving birth to the next pup at the same time. A greenish/brown discharge may suggest a placenta has separated. If you see this, a puppy should be born within the next 2-4 hours.

Answer: 1×10^11

Explanation:

concept to know: scientific notation must be written in the form of a × 10^b

where 0<a<10.

100 billion= 100,000,000,000

there are 11 zeros after 1

1 × 10^11

Hope this helps!! :)

Answer:

yes it is as it has a chemical formula which cannot be changed

Explanation:

1 mile = 1.61 km and 1 km = 1000 m

The speed of light is [tex]3\times 10^8\ m/s[/tex]. We need to convert it into miles per hour.

1 m = (1/1000) km

[tex]3\times 10^8\ m=\dfrac{3\times 10^8}{1000}\\\\=3\times 10^5\ km[/tex]

1 km = (1/1.61) miles

[tex]3\times 10^5\ km =\dfrac{3\times 10^5}{1.61}\\\\=1.86\times 10^5\ \text{miles}[/tex]

So, [tex]v=1.86\times 10^5\ \text{miles/s}[/tex]

Hence, this is the required solution.

Answer:

Explanation:

Hello,

In this case, considering the given specific gravity we are to compute the density of the 64% HNO3 solution:

[tex]\rho=1.24*1g/mL=1.24g/mL[/tex]

In such a way, since the given solution of nitric acid is 64 % by mass, we've got:

[tex]\frac{64gHNO_3}{100g\ solution}[/tex]

Thus, by using the previously computed density and the molar mass of HA (90.2 g/mol) we can compute the required molar concentration as follows:

[tex]M=\frac{(100g-64g)HA}{100g\ solution}*\frac{1.24g\ solution }{1mL \ solution}*\frac{1000mL\ solution}{1L\ solution}*\frac{1molHA}{90.2gHA} \\\\M=4.95M[/tex]

Regards.

Answer:

The specific heat capacity is the heat that a body or a system needs to administer so that it can increase its internal temperature.

Explanation:

The calorific capacity is measured in several units, it varies a lot between products, reactants or the same systems since each one is independent in its composition and this conditions it.

As for its mathematical calculation, it is the quotient, that is, the division between the dose of energy transferred to a body and the change in temperature that it experiences.

Answer:

i try to solve it for you, and i aplode a similer question for you

Explanation:

Answer:

107.55 J, 88.67 cal

Explanation:

1 Joule = 0.239 Calories

450 cal x 0.239 = 107.55 J

3.5 x 106 = 371

371 J = 371 x 0.239 cal

371 J = 88.67 cal

Answer:

20 drops

Explanation:

Step 1: Given data

Step 2: Calculate the volume of water added

We calculate the volume of water added by subtracting the initial volume to the final volume.

36.0 mL - 23.0 mL = 13.0 mL

Step 3: Calculate the number of drops in 1 mL

We will divide the number of drops of water added by the volume they represent.

265 drops / 13.0 mL = 20.4 drops/1 mL ≈ 20 drops/1 mL

Answer:

115g

Explanation:

100*8=800

800+150+200=1150

1150/10=115

Answer:

[tex]M=4.00\frac{mol}{L}=4M[/tex]

Explanation:

Hello.

In this case, we should remember that a molar concentration is defined in terms of the moles and volume in liters as shown below:

[tex]M=\frac{mol}{L}[/tex]

Thus, for the given information we obtain:

[tex]M=\frac{8.000mol}{2.00L}\\ \\M=4.00\frac{mol}{L}=4M[/tex]

Best regards.

The question is missing parts. The complete question is as follows.

Consider the two gaseous equilibria involving SO2 and the corresponding equilibrium constants at 298K:

[tex]SO_{2}_{(g)} + \frac{1}{2}O_{2}[/tex] ⇔ [tex]SO_{3}_{(g)}[/tex]; [tex]K_{1}[/tex]

[tex]2SO_{3}_{(g)}[/tex] ⇔ [tex]2SO_{2}_{(g)}+O_{2}_{(g)}; K_{2}[/tex]

The values of the equilibrium constants are related by:

a) [tex]K_{1}[/tex] = [tex]K_{2}[/tex]

b) [tex]K_{2} = K_{1}^{2}[/tex]

c) [tex]K_{2} = \frac{1}{K_{1}^{2}}[/tex]

d) [tex]K_{2}=\frac{1}{K_{1}}[/tex]

Answer: c) [tex]K_{2} = \frac{1}{K_{1}^{2}}[/tex]

Explanation: Equilibrium constant is a value in which the rate of the reaction going towards the right is the same rate as the reaction going towards the left. It is represented by letter K and is calculated as:

[tex]K=\frac{[products]^{n}}{[reagents]^{m}}[/tex]

The concentration of each product divided by the concentration of each reagent. The indices, m and n, represent the coefficient of each product and each reagent.

The equilibrium constants of each reaction are:

[tex]SO_{2}_{(g)} + \frac{1}{2}O_{2}[/tex] ⇔ [tex]SO_{3}_{(g)}[/tex]

[tex]K_{1}=\frac{[SO_{3}]}{[SO_{2}][O_{2}]^{1/2}}[/tex]

[tex]2SO_{3}_{(g)}[/tex] ⇔ [tex]2SO_{2}_{(g)}+O_{2}_{(g)}[/tex]

[tex]K_{2}=\frac{[SO_{2}]^{2}[O_{2}]}{[SO_{3}]^{2}}[/tex]

Now, analysing each constant, it is easy to see that [tex]K_{1}[/tex] is the inverse of [tex]K_{2}[/tex].

If you doubled the first reaction, it will have the same coefficients of the second reaction. Since coefficients are "transformed" in power for the constant, the relationship is:

[tex]K_{2}=\frac{1}{K_{1}^{2}}[/tex]

Answer:

London forces only

Explanation:

Dimethyl ether is a nonpolar organic compound. Remember that for nonpolar organic substances, London forces are the primary intermolecular forces present.

Since dimethyl ether is a nonpolar organic compound, then it has London forces as its major intermolecular force. Intermolecular forces hold molecules of a substance together in a given state of matter.

Answer:

1219.5 kj/mol

Explanation:

To reach this result, you must use the formula:

ΔHºrxn = Σn * (BE reactant) - Σn * (BE product)

ΔHºrxn = [1 * (BE C = C) + 2 * (BE C-H) + 5/2 * (BE O = O)] - [4 * (BE C = O) + 2 * (BE O-H).

The BE values are:

BE C = C: 839 kj / mol

BE C-H: 413 Kj / mol

BE O = O: 495 kj / mol

BE C = O = 799 Kj / mol

BE O-H = 463 kj / mol

Now you must replace the values in the above equation, the result of which will be:

ΔHºrxn = [1 * 839 + 2 * (413) + 5/2 * (495)] - [4 * (799) + 2 * (463) = 1219.5 kj/mol

Based on the bond energies, the reaction

HC≡CH(g) + 5/2 O₂(g) → 2 CO₂(g) + H₂O(g) has a standard enthalpy of reaction of - 1222 kJ/mol.

The bond energies (E) of the reactions can help to calculate the standard enthalpy of the reaction (ΔH°rxn) using the following expression.

[tex]\triangle H_ \degrees {rxn} = \sum E_{reactants} - \sum E_{products}[/tex]  

Solution:

bond energies in the formula:

[tex]\triangle H_ \degrees {rxn} = 835+ 2(411) + 2.5(494) - 4(799) - 2(459)[/tex]

= 1222 kJ/mol  

Thus, Based on the bond energies, the reaction:

HC≡CH(g) + 5/2 O₂(g) → 2 CO₂(g) + H₂O(g) has a standard enthalpy of reaction of -1222 kJ/mol.  

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Answer:

Explanation:

The density of a substance can be found by using the formula

[tex]Density = \frac{mass}{volume} [/tex]

From the question

mass = 52 g

volume = 26 mL

Substitute the values into the above formula and solve for the density

That's

[tex]Density = \frac{52}{26} [/tex]

We have the final answer as

Hope this helps you