All changes in chemistry are chemical? True or false?

When 48.6 g of water vaporizes at its boiling point (100.0 °C), the change in the entropy is 0.292 kJ/K.

First, we will calculate the change in the enthalpy (ΔH) when 48.6 g of water vaporizes considering the following relationships.

[tex]\Delta H = 48.06 g \times \frac{1mol}{18.02g} \times \frac{40.7kJ}{mol} = 109kJ[/tex]

Then, we will convert 100.0 °C (T) to Kelvin using the following expression.

[tex]T = K = \° C + 273.15 = 100.0\° C + 273.15 = 373.2 K[/tex]

Finally, we will calculate the change in the entropy (ΔS) for this process using the following expression.

[tex]\Delta S = \frac{\Delta H }{T} = \frac{109kJ}{373.2K} = 0.292kJ/K[/tex]

When 48.6 g of water vaporizes at its boiling point (100.0 °C), the change in the entropy is 0.292 kJ/K.

Learn more: https://brainly.com/question/13146879

Final answer:

To determine the actual yield of ammonia gas, convert the mass of nitrogen gas to moles, calculate the theoretical yield using stoichiometry, and then apply the percent yield. The actual yield for a 68.2% percent yield from 2.00 kg of nitrogen is 1658.41 g NH3.

Explanation:

To calculate the actual yield of ammonia gas (NH3) production from nitrogen (N2) and hydrogen (H2) gases when given the percent yield and mass of nitrogen gas, we'll first need to convert the mass of nitrogen to moles, then calculate the theoretical yield of ammonia based on stoichiometry, and finally use the percent yield to find the actual yield.

Step-by-step Calculation:

Calculate moles of nitrogen: Molecular weight of N2 is 28.02 g/mol. 2.00 kg of N2 is 2000 g. Moles = 2000 g / 28.02 g/mol = 71.38 mol N2.

Using the balanced chemical equation (N2 + 3H2 → 2NH3), we see the stoichiometry is 1:2 for nitrogen to ammonia. So, moles of NH3 = 2 moles NH3/mole N2 × 71.38 mol N2 = 142.76 mol NH3.

Convert moles of NH3 to grams: Molecular weight of NH3 is 17.03 g/mol. The theoretical yield in grams = 142.76 mol NH3 × 17.03 g/mol = 2431.89 g NH3.

Calculate actual yield using the percent yield: Actual Yield = Percent Yield / 100 × Theoretical Yield = 68.2% / 100 × 2431.89 g = 1658.41 g NH3.

Therefore, the actual yield of ammonia when starting with 2.00 kg of nitrogen gas and a percent yield of 68.2% is 1658.41 g.

To convert atoms of magnesium to moles, divide the given number of atoms by Avogadro's number. For 1.2×10^24 atoms it results in 1.99 moles of magnesium.

To convert 1.2×1024 atoms of magnesium into moles, we use Avogadro's number, which is 6.022×1023 atoms per mole. This conversion factor allows us to change the number of atoms into moles since one mole of any substance contains Avogadro's number of atoms, ions, or molecules.

Therefore, 1.2×1024 atoms of magnesium is equal to 1.99 moles of magnesium.

Answer: The correct answer is A) Use an inclined plane of 8 m

Work :

Work is defined as force applied to an object to move it to some distance . It is calculated as product of force and displacement .

W = F* d

Where : W =work (N-m) F = force (N) d = displacement (m)

When a body is lifted , work can be expressed as :

W = m*g*h ( h = height )

Also force due to gravitation can be given as

F = m* g

where :

g = gravitational acceleration ([tex] 9.8 \frac{m}{s^2} [/tex]

Hence Work can be written as : W = F * h

Given :

Force on load due to gravitation = 100 N Height = 2 m

Force applied = 25 N displacement = ?

Work done to lift the load to 2 m = F * h

= 100 N * 2 m = 200 N-m

Plugging W = 200 N-m in work formula

W = F* d

200 N-m = 25 N * d

Dividing both side by 25 N

[tex] \frac{200N-m}{25 N} = \frac{25 N * d}{25 N} [/tex]

d = 8 m

Hence, to lift the load using 25 N , the inclined plane of 8 m can be used .

Answer:

Two nonmetals with the same electronegativity will form a non polar covalent bond.

Explanation:

The type of bond between atoms is classified in 3 big groups:

Apart from that, depending on the electronegativity difference, the covalent bonds are clasified in polar and non polar:

- Polar covalent bond: the difference of electronegativity is important but less than an ionic bond (between 0 and 2).

- Non polar covalent bond: this occurs when the atoms forming bonds have the same electronegativity.

So, analyzing the statement, if we have two nonmetals it is a covalent bond, and if the two nonmetals atoms have the same electronegativity the bond will be non polar.

Answer:

Geiger counter and scintillation counter

Explanation:

The Geiger counter was invented by Hans Geiger in 1908 to measure the levels of radiation in bodies and the environment, so it is one of the indispensable equipment for the inspector to detect radiation leaks in a nuclear power plant. It contains a tube with argon, which ionizes by being crossed by alpha and beta particles of radiation, closing the electric circuit and triggering the counter.

Similarly, a scintillation detector is an apparatus used to detect ionizing radiation. When something in the environment has been reached by radiation, this detector emits a small ray of light, indicating the radiation contamination.

Answer:

A. Geiger counter and scintillation counter

Explanation:

The amount of the excess reactant remaining after the limiting reactant is consumed can be found by subtracting the amount used in the reaction from the initial amount, using stoichiometry to calculate these values.

To determine the amount of the excess reactant remaining after the limiting reactant is completely consumed, you will need to perform some calculations. First, it is necessary to determine which reactant is the limiting one. This can be done by comparing their mole ratios in the balanced chemical equation. Then, you should calculate the amount of product that the limiting reactant can make.

Next, you can use the stoichiometry of the reaction to figure out how much of the excess reactant was needed to react with the limiting reactant. Subtract this from the total amount of the excess reactant present at the start to get the amount remaining, expressed in grams. Remember that your answer should be reported to two significant figures.

https://brainly.com/question/35053254

#SPJ2

To find the  moles equivalent to 2.50x10²⁰ atoms of Fe, you divide the given number of atoms by Avogadro's number (6.022x10²³ atoms/mole). This yields approximately 0.415 moles of Fe.

To calculate the number of moles equivalent to 2.50x10²⁰ atoms of Fe (Iron), you can use Avogadro's number, which is 6.022x10²³ atoms/mole. Let's divide the given no. with Avogadro's number. Let's do the computation:

2.50x10²⁰ atoms Fe * (1 mol Fe / 6.022x10²³ atoms Fe) = ~0.415 moles of Fe

This means that 2.50x10²⁰ atoms of Fe is equivalent to 0.415 moles. Avogadro's number is a fundamental constant in chemistry and is used to convert between the atomic scale and macroscopic scale.

https://brainly.com/question/33720401

#SPJ12

2.50x10^20 atoms of Fe are equivalent to approximately 4.15x10^-4 moles. This is calculated by dividing the number of atoms by Avogadro's number (6.022x10^23 atoms per mole).

To calculate how many moles are equivalent to 2.50x10^20 atoms of Fe, we use Avogadro's number, which states that one mole of any substance contains 6.022x10^23 elementary entities (like atoms). Therefore, to convert the number of atoms to moles, we divide the number of atoms by Avogadro's number.

In this case, (2.50x10^20) / (6.022x10^23), which equals approximately 4.15x10^-4 moles of Fe.

https://brainly.com/question/8512069

#SPJ12

Answer:

Concentration of solution in percent by mass is 13.3% CaO

Explanation:

% by mass = [tex]\frac{mass of solute}{mass of solution}\times 100[/tex]

Here solute is CaO and solvent is water.

So, mass of solution = (mass of solute)+(mass of solvent)

                                  = (mass of CaO)+(mass of water)

                                   = 32.5 g + 212 g

                                    = 244.5 g

So, Concentration of solution by percent mass = [tex]\frac{mass of CaO}{mass of solution}\times 100[/tex] = [tex]\frac{32.5}{244.5}\times 100[/tex] = 13.3 %

Final answer:

The daughter nuclide produced when ¹°Sr undergoes beta decay is ¹°Y (yttrium-90), which is represented by the nuclear equation ¹°Sr → ¹°Y + β⁻.

Explanation:

When ¹°Sr undergoes beta decay, it emits an electron (beta particle) and transforms into a different element. The loss of the electron results in an increase of the atomic number by one while the mass number remains the same. Therefore, the new atomic number will be 39 (as strontium has atomic number 38), and the mass number stays at 90. The daughter nuclide produced from this decay is ¹°Y (yttrium-90).

The nuclear equation for this ß-decay process is:
¹°Sr → ¹°Y + β⁻

Using the Clausius-Clapeyron equation, we can derive that the boiling point of water at 880 torr is closest to 90°C. Thus, among the given options, the boiling point of water at 880 torr is most likely to be 92°C.

The subject question is considering the boiling point of water at differing pressures. The standard boiling point of water is 100°C at 1 atmospheric pressure (or 760 torr). However, boiling point changes with changes in atmospheric pressure.

 By using the Clausius-Clapeyron equation, which establishes a relationship between the vapor pressure and temperature of a substance, we can establish that at 880 torr, the boiling point is likely to be close to 90°C, given that the vapor pressure of water is 68kPa at about this temperature. Therefore, among the options given, 92°C is the most likely boiling point of water at 880 torr.

https://brainly.com/question/2153588

#SPJ3

The molecule 2,2-dimethyl-4-propyloctane has five secondary carbons which are those bonded to two other carbon atoms.

The hydrocarbon 2,2-dimethyl-4-propyloctane belongs to the class of alkanes, characterized by single bonds between carbon atoms. This molecule consists of an 8-carbon chain (octane), with three side branches: two methyl groups (-CH3) on the second carbon and a propyl group (-CH2-CH2-CH3) on the fourth carbon. When identifying secondary carbons, which are carbon atoms bonded to two other carbon atoms, it becomes evident that 2,2-dimethyl-4-propyloctane contains five secondary carbons.

The two carbons on either end of the main chain don't fit the criteria of secondary carbons as they are bonded to only one other carbon atom. The five secondary carbons are as follows: two from the main chain (excluding the ends); two found at the ends of the propyl branch; and one where the methyl branches connect to the main chain.

https://brainly.com/question/35559152

#SPJ11

Answer:

C  

Low frequency                                     High frequency

Long wavelength                                 Short wavelength

Low radiant energy                              High radiant energy

Explanation:  

I took the k-12 4.04 quiz, let me know if I am wrong.

The electromagnetic spectrum is the distribution of electromagnetic radiation. The third image's low frequency, wavelength, and radiant energy are correctly labeled.

An electromagnetic wave spectrum is the distribution of electromagnetic radiations based on frequency and wavelength. In electromagnetic radiation, energy is given by Planck's constant and frequency.

Also, the relation between the frequency and the wavelength is given as,

[tex]\nu = \rm \dfrac{c}{\lambda}[/tex]

From these relations, it can be said that the frequency is directly proportional to energy, and is inversely proportional to the wavelength.

Therefore, if on the left side low frequency, low radiant energy, and long-wavelength are present then, on the right side opposite will be observed.

Learn more about the electromagnetic spectrum here:

https://brainly.com/question/3914212

The given reaction of metallic sodium with sulphur involves two electrons which are lost  from two sodium atoms and gained by the sulphur atom. Thus sodium atom oxidizes from 0 to +1 and sulphur reduces from 0 to -1.

A redox reaction involves oxidation of one reactant species and reduction of other species. The species which loss or donate electrons are oxidized to higher oxidation states whereas, the species which gain one or more electrons are reduced to lower oxidation states.

Metals are electron rich and will lose electrons easily to a non-metal during chemical bonding. Here the valency of sulphur is two thus it needs to gain 2 electrons. One sodium donate one electrons and thus two sodium atoms are needed to react with sulphur.

The oxidation reaction here is :

[tex]\rm 2 Na \rightarrow 2Na^{+} + 2 e^{-}[/tex]

Reduction of sulphur is written as:

[tex]\rm S + 2e ^{-} \rightarrow S^{2-}[/tex]

Therefore, the number of electrons involved in this oxidation -reduction reaction is 2.

To find more on redox reactions, refer here:

https://brainly.com/question/13978139

#SPJ2

Final answer:

The internal energy (u) of one mole of air at 35°C is approximately 6400 J when calculated using the ideal gas law and assuming air is a diatomic gas.

Explanation:

The internal energy (u) of one mole of air on a very hot summer day, which is 35°C, can be estimated using the ideal gas law and the concept of heat capacity at constant volume (Cv). To find the internal energy, we must convert the given temperature to Kelvin by adding 273.15 to the Celsius temperature, which gives us 308.15 K (35°C + 273.15). Air is typically considered to be a diatomic molecule, particularly for dry air, which mainly consists of nitrogen and oxygen molecules. The approximate molar heat capacity at constant volume (Cv) for a diatomic gas like air is about 5R/2, where R is the universal gas constant (8.314 J/(mol·K)). Therefore, the internal energy (U) of one mole of air at this temperature is U = Cv × T = (5/2) × R × T. Plugging in the numbers, we get U = (5/2) × (8.314 J/(mol·K)) × (308.15 K). This would yield an internal energy of approximately 6412.5 J, which can be rounded to 6400 J to two significant figures.

The number of moles of tin needed to react with 8.4 moles of hydrogen fluoride are 4.2 Moles. It can be founded with the help of limiting reagent concept.

The limiting reactant (or limiting reagent) is the reactant that gets consumed first in a chemical reaction and therefore limits how much product can be formed.

Given Balance Chemical Equation ;

                                Sn (s)  +  2 HF (g)   →    SnF₂ (s)  +  H₂ (g)

According to Equation,

                      2 Moles of HF requires  =  1 Mole of Sn

Therefore,

                8.4 Moles of HF will require  =  X Moles of Sn

Solving for X,

                           X  =  (8.4 mol × 1 mol) ÷ 2 mol

                           X  =  4.2 Moles of Sn

Hence, The number of moles of tin needed to react with 8.4 moles of hydrogen fluoride are 4.2 Moles.

Learn more about Limiting reagent here ;

https://brainly.com/question/20070272

#SPJ1

The rock and roll station at [tex]107.0 MHz[/tex] has higher energy photons with approximately [tex]\(7.09 \times 10^{-26}\) joules[/tex]

The opera station at [tex]90.5 MHz[/tex] has lower energy photons with approximately [tex]\(5.99 \times 10^{-26}\) joules.[/tex]

To determine which radio station's signal has longer wavelengths and which has higher energy, we need to use the relationships between frequency, wavelength, and energy for electromagnetic waves.

1. Wavelength

The wavelength (\(\lambda\)) of a wave is related to its frequency ([tex]\(f\)[/tex]) and the speed of light ([tex]\(c\)[/tex]) by the equation:

[tex]\[ \lambda = \frac{c}{f} \][/tex]

Where:

[tex]\(c\)[/tex] is the speed of light ([tex]\(3 \times 10^8\) meters per second[/tex]).

[tex]\(f\)[/tex] is the frequency of the wave.

Opera Station ([tex]90.5 MHz[/tex])

Frequency: [tex]\(90.5 \times 10^6\) Hz[/tex]

[tex]\[ \lambda_{\text{opera}} = \frac{3 \times 10^8 \, \text{m/s}}{90.5 \times 10^6 \, \text{Hz}} = \frac{3 \times 10^8}{90.5 \times 10^6} = 3.31 \, \text{meters} \][/tex]

Rock and Roll Station ([tex]107.0 MHz[/tex])

Frequency: [tex]\(107.0 \times 10^6\) Hz[/tex]

[tex]\[ \lambda_{\text{rock}} = \frac{3 \times 10^8 \, \text{m/s}}{107.0 \times 10^6 \, \text{Hz}} = \frac{3 \times 10^8}{107.0 \times 10^6} = 2.80 \, \text{meters} \][/tex]

The opera station at [tex]90.5 MHz[/tex] has a longer wavelength of approximately [tex]3.31 meters[/tex].

The rock and roll station at [tex]107.0 MHz[/tex] has a shorter wavelength of approximately [tex]2.80 meters[/tex]

2. Energy

The energy ([tex]\(E\)[/tex]) of a photon is related to its frequency ([tex]\(f\)[/tex]) by the equation:

[tex]\[ E = h f \][/tex]

Where:

[tex]\(h\)[/tex] is Planck's constant ([tex]\(6.626 \times 10^{-34}\) Joule seconds[/tex]).

[tex]\(f\)[/tex] is the frequency of the wave.

Opera Station ([tex]90.5 MHz[/tex])

[tex]\[ E_{\text{opera}} = 6.626 \times 10^{-34} \, \text{Js} \times 90.5 \times 10^6 \, \text{Hz} = 5.99 \times 10^{-26} \, \text{J} \][/tex]

Rock and Roll Station ([tex]107.0 MHz[/tex])

[tex]\[ E_{\text{rock}} = 6.626 \times 10^{-34} \, \text{Js} \times 107.0 \times 10^6 \, \text{Hz} = 7.09 \times 10^{-26} \, \text{J} \][/tex]

Final answer:

Butanoic acid can be converted to butanal via a reduction process using a reducing agent such as lithium aluminum hydride, followed by hydrolysis.

Explanation:

Converting butanoic acid to butanal involves a reduction process, which can be carried out using reducing agents such as lithium aluminum hydride (LiAlH₄) or borane (BH₃). The reaction with LiAlH₄ is usually carried out in dry ether as a solvent, and it can be followed by careful hydrolysis to give the aldehyde, butanal. The overall reaction can be summarized as:

Butanoic acid (C₄H₈O₂) is treated with the reducing agent LiAlH₄.

The acid is reduced to the corresponding aldehyde, butanal (C₄H₈O).

After the reduction, the reaction mixture is hydrolyzed, which involves adding water to the reaction mixture.

This is different from esterification, which is the reaction between an acid and an alcohol, as described in the esterification of ethanol and butanoic acid to form ethyl butanoate and water.

The biochemical production of butanol from butyric acid is similarly not a direct route for synthesizing butanal, but it is an important process for biomass conversion.