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Answer:

Q = -33.6kcal .

Explanation:

Hello there!

In this case, according to the equation for the calculation of the total heat of reaction when a fixed mass of a fuel like ethane is burnt, we can write:

[tex]Q=n*\Delta _cH[/tex]

Whereas n stands for the moles and the other term for the enthalpy of combustion. Thus, for the required total heat of reaction, we first compute the moles of ethane in 3 g as shown below:

[tex]n=3g*\frac{1mol}{30.08g}=0.1mol[/tex]

Next, we understand that -337.0kcal is the heat released by the combustion of 1 mole of ethane, therefore, to compute Q, we proceed as follows:

[tex]Q=0.1mol*-337.0\frac{kcal}{mol}\\\\Q=-33.6kcal[/tex]

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Answer:

4.80×10³ years

Explanation:

Let the original amount (N₀) of ²²⁶Rn = 1 g

Therefore,

12.5% of the original amount = 12.5% × 1 = 12.5/100 × 1 = 0.125 g

Next, we shall determine the number of half-lives that has elapse. This can be obtained as follow:

Original amount (N₀) = 1

Amount remaining (N) = 0.125 g

Number of half-lives (n) =?

N = 1/2ⁿ × N₀

0.125 = 1/2ⁿ × 1

0.125 = 1/2ⁿ

Cross multiply

0.125 × 2ⁿ = 1

Divide both side by 0.125

2ⁿ = 1/0.125

2ⁿ = 8

Express 8 in index form with 2 as the base

2ⁿ = 2³

n = 3

Thus, 3 half-lives has elapsed.

Finally, we shall determine the time taken for only 12.5% of the original sample of ²²⁶Rn to remain.

This can be obtained as follow:

Half-life (t½) = 1.60×10³ years

Number of half-lives (n) = 3

Time (t) =?

t = n × t½

t = 3 × 1.60×10³

t = 4.80×10³ years.

Thus, it will take 4.80×10³ years for 12.5% of the original sample of ²²⁶Rn to remain.

Answer:

We will Multiply the number of moles with Avagadro's number

So it will be (2.04×1023)×6.022×10^23

NA means Avagadro's number

Answer:  

A i took the quiz

Explanation:

Answer:

oxygen = 4.7 * 10^-6

Nitrogen = = 9.7 * 10^6

Explanation:

partial pressure of oxygen = 0.20 atm

partial pressure of Nitrogen = 0.80 atm

calculate the mole fractions of oxygen and Nitrogen in water

Temp = 298k

applying henry's law

molar conc of oxygen in water ( Coxygen )

= Kp = 1.3 * 10^-3 Mol/L.atm * 0.20 atm = 2.6 * 10^-4 Mol

molar conc of Nitrogen in water ( Cnitrogen )

= Kp = 6.8 * 10^-4 Mol/L.atm * 0.80 atm = 5.4 * 10^-4

next Given that the number of moles in 1 liter of water = 55.5 mol  

therefore the mole fraction of oxygen

= 2.6 * 10^-4 / 55.5

= 4.7 * 10^-6

mole fraction of Nitrogen

= 5.4 * 10^-4  / 55.5

= 9.7 * 10^6

4.0 moles NaHCO

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Atomic Structure

Stoichiometry

Step 1: Define

[Given] 2.4 × 10²⁴ molecules NaHCO

[Solve] moles NaHCO

Step 2: Identify Conversion

Avogadro's Number

Step 3: Convert

Step 4: Check

Follow sig fig rules and round. We are given 2 sig figs.

3.98539 moles NaHCO ≈ 4.0 moles NaHCO

Answer:

pretty sure its B but if not I'm sorry

2 moles of O₂ is equal to 64 g of O₂ is the only correct statement among the given statements. Hence, Option (A) is correct. It can be solved by mole concept

The mole, symbol mol, is the SI base unit of amount of substance.

The quantity amount of substance is a measure of how many elementary entities of a given substance are in an object or sample.

formula ;

n = given weight / molecular weight

  = 64 / 32

  = 2 moles

Therefore, 2 moles of O₂ is equal to 64 g of O₂ is the only correct statement among the given statements. Hence, Option (A) is correct.

Learn more about mole concept here ;

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Answer:

d

Explanation:

The order of decreasing the acidity of the given compounds:

Benzoic acid > Benzyl alcohol > Methylbenzene.

The acidic strength of an acid can be described as the ability of the acid to lose its H⁺ ion. In general, the dissociation of acid can be represented as:

HA  →  H⁺  +  A⁻

Some examples of strong acids are hydrochloric acid, sulfuric acid (H2SO₄), perchloric acid  (HClO₄), etc.

The benzoic acid is a very strong acid with pka value of 4.5 as it contains the (-COOH) group. The Benzyl alcohol with pka value of 15.4 as it contains the (-CH₂OH) group attached to the benzene ring. The methylbenzene with pka value of 41 has the lowest acidity as it contains the methyl group attached to the benzene ring.

Therefore, the order of acidic strength for the given compounds is  Benzoic acid > Benzyl alcohol > Methylbenzene.

Learn more about acidic strength, here:

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Answer: 1:16

Explanation:

Answer: m-%(Ca) = 40.08 / 110.98

Explanation: molar mass of CaCl2 is 40.08+ 2·35.45 = 110.98

Think you have one mole substance. It contains 40.08 g Ca

Answer:

It’s Photosynthesis

Explanation:

Don’t click the file it’s a virus ! Also I hope I helped!

Answer:

Explanation:

First we convert the given masses of each element into moles, using their respective molar masses:

Now we divide them in order to calculate the molar ratio of S to Fe:

Meaning that for each 1 Fe mol, there's 1.5 S moles. We can write that as Fe₁S₁.₅

Finally we double those subscripts so that they become the lowest possible integers: Fe₂S₃.

Answer:

Compound

Explanation:

H2O is made up of multiple types of atoms, which makes it a compound. It isn't an element because they only consist of one type of atom.

Answer:

Explanation:

Answer:

C. Chemical change

Explanation:

A physical change is where something is changed but it doesnt affect the build up of the chemical. For example, if you broke sticks and threw them on the ground, that would be a physical change because the change is happening to the physical being of the object and not its chemical buildup. However, if you lit those sticks on fire, that would be considered a chemical change because you end up with two substances, ash and the remnants of the stick. A nuclear reaction would result in something blowing up so its not that. And a physical property is like what it looks like or how it smells. Hope I helped you!

Answer:

Follows are the solution to this question:

Explanation:

Methane inlet humidity content of [tex]=7.00\%[/tex]

Methane moisture outlet content [tex]=0.05\%[/tex]

Zeolite absorption humidity [tex]= 6.95\%[/tex]

Dry zeolite 1 kg will accommodate water[tex]= 0.1000 \ kg[/tex]

One kilogram of Dry Zeolite will carry water from [tex]=0.1000\ kg[/tex]

The water can contain 1000 kg of zeolite [tex]= 100 \ kg[/tex]

Methane which would be made [tex]=\frac{100}{6.95\%}= 1,439 \ kg[/tex]

That's why it will be producing 1439 kg of methane.

The amount of methane that can be produced before the regeneration of zeolite is 1,439 kg.

What is zeolite?

Zeolite belongs from the family of hydrated aluminosilicate minerals, in which alkali and alkaline earth metals are present.

In the question, it is given that:

Capacity of 1kg of zeolite to hold water = 0.100kg

Capacity of 1000kg of zeolite to hold water = 100kg

Inlet moisture content of the methane = 7.00 % (by mass)

Outlet moisture content of the methane = 0.05% (by mass)

Capacity of zeolite to absorb methane content = 6.95 %

Amount of methane before the regeneration of zeolite = 100kg / 6.95% = 14.39% of kg = 1,439 kg

Hence, 1,439 kg methane will be produced before the zeolite must be regenerated.

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Answer:

See explanation

Explanation:

When (S)-2-methylcyclopentanone is treated with an acid, the carbonyl oxygen atom is protonated.

This leads to the emergence of a positive charge on the cabonyl oxygen. Then the C=O bond is now transformed into H-C-OH where C is a carbocation which leads to a racemic mixture. Loss of a proton from the adjacent carbon atom completes the mechanism.

In this process, the optically active (S)-2-methylcyclopentanone is converted to a pair of diastereomers thereby loosing its optical activity.

Answer:

C) Mercury based thermometer

Explanation:

Answer:

Mercury based thermometer

Explanation:

When you touch a lightbulb it is warm. Hairdryer produces heat to dry your hair. Stove heats up to warm food and liquids up.

Answer: curiosity?

Explanation:

Answer:

1 mole = 28.0101

Hence,

82.4 = around 2.8 mole

Have a great day <3

Answer:

13.5 %

Explanation:

First we calculate the mass of 500 mL of water, using its density:

Then we calculate the mass percent of potassium sulfate, using the formula:

Mass of Potassium Sulfate / Total Mass * 100%

Explanation:

Gold (AU)................