Refrigerators make use of the heat absorption required to vaporize a volatile liquid. a fluorocarbon liquid being investigated to replace a chlorofluorocarbon has a molar heat of vaporization of 26 kj/mol at 250 k and 750 torr. calculate

Answers

Answer 1
Final answer:

Refrigerators utilize the principle of heat absorption to vaporize a refrigerant, removing heat from the interior of the refrigerator and releasing it outside. The process involves the cycle of vaporization and condensation, powered by electricity, which maintains the cool temperature inside the fridge.

Explanation:

Refrigerators work based on the principle of

heat absorption

required to vaporize a volatile liquid. In this case, the volatile liquid being used as a refrigerant is a

fluorocarbon

. This liquid absorbs heat from the inside of the refrigerator (at the evaporator), causing it to vaporize. This heat is then released outside the refrigerator (at the condenser) when the vaporized refrigerant is condensed back to a liquid. The heat of vaporization for any substance is the amount of heat required to convert 1 mole of that substance from liquid to gas at constant temperature and pressure. Here, your fluorocarbon has a molar heat of vaporization of 26 kJ/mol. To complete the cycle, work is done on the refrigerant (which we pay for in our electricity bills) to move it through the coils in the refrigerator and begin the cycle again. This overall process is what keeps the refrigerator cool.

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Related Questions

Which laws can be combined to form the ideal gas law?
A. Boyle’s law and Charles’s law
B. Gay-Lussac’s law and Avogadro’s law
C. Charles’s law, Avogadro’s law, and Boyle’s law
D. Dalton’s law, Gay-Lussac’s law, and Avogadro’s law

Answers

Answer: Charles's law, Avogadro's law and Boyle's law.

Justification:

Boyle's law states that at constant temperature  PV = constant

Charles law states that at constant pressure V/T = constant

Avogadro's law states that at constant pressure ant temperature, equal volume of gases contain equal number of moles: V/n = constant

Ideal gas law states PV/nT = constant => PV = nT*constant = PV = nTR

Answer:

Charles's law, Avogadro's law and Boyle's law.

Explanation:

I think

which example is a homogeneous mixture
a fruit salad
b apple juice
c granite
d sand at the beach

Answers

The correct answer is b apple juice.A homogeneous mixture is chemicals that dissolve in water. Because apples are mixed in water, it is homogeneous. Hope I explained that well.

Final answer:

Apple juice is a homogeneous mixture due to its uniform composition throughout, making it visually the same, unlike the other given options.

Explanation:

Among the options given, apple juice is an example of a homogeneous mixture. A homogeneous mixture, or solution, has a uniform composition throughout and does not contain visibly distinguishable parts. Apple juice's uniform composition makes it visually the same throughout, unlike a fruit salad, granite, or sand at the beach, which are examples of heterogeneous mixtures where the composition is not uniform and the different parts can be seen. Other examples of homogeneous mixtures include sports drinks, air, and solutions of salt in water.

G oil of wintergreen, c8h8o3 is prepared when methanol, ch3oh, is reacted with salicylic acid, c7h6o3. what is the percent yield of a reaction in which 15.3 g of oil of wintergreen is collected after 16.3 g salicylic acid is reacted with an excess of methanol? ch3oh + c7h6o3 c8h8o3 + h2o

Answers

One mole or 138 g of salicylic acid produces one mole or 152 g of wintergreen oil. Thus, theoretically 16.3 g of the acid will produce 17.9 g of oil but only 15.3 g is produced. Therefore, the percent yield of the reaction is 85.4 %.

What is percent yield?

Percent yield of a reaction is the ratio of the actual yield to the theoretical yield of the product in a reaction multiplied by 100.

Molar mass of salicylic acid = 138 g/mol

Molar mass of winter green oil = 153=2 g/mol

one mole of salicylic acid produces one mole of oil. Thus, mass of oil produced from 16.3 g of acid = (16.3 × 152 )/ 138 = 17.9g

Thus, theoretical yield = 17.9 g.

Actual yield = 15.3 g

Percent yield = actual / theoretical yield ×  100

                      = 15.3 /17.9 ×  100 = 85.4 %.

Therefore, the percent yield of the reaction is 85.4%.

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The per cent yield of the reaction to produce oil of wintergreen from salicylic acid and methanol is approximately 93.87% given that 15.3 g of the product is collected and 16.3 g of the reactant is used.

The per cent yield of oil of wintergreen (methyl salicylate) reaction can be calculated using the formula: per cent yield = (actual yield / theoretical yield) imes 100%. To find the theoretical yield, we would first need the balanced chemical equation for the reaction, which is CH₃OH + C₇H₆O₃------>C₈H₈O₃ + H₂O. Given that 16.3 g of salicylic acid is reacted, we assume a 100% conversion based on the stoichiometry of the reaction, which yields 16.3 g of oil of wintergreen. Therefore, the per cent yield (15.3 g actual / 16.3 g theoretical) imes 100%, which equals approximately 93.87%.

Hydrogen bonding is necessary for
bonding carbon to oxygen.
forming double-stranded DNA molecules.
decreasing the boiling point of liquids such as water.
causing van der Waals interactions.

Answers

The correct option is FORMING DOUBLE STRANDED DNA MOLECULES.
The DNA molecule is a very important molecule in living organism; it is the basis of inheritance in living organisms. Each DNA molecule has two strands and these strands are held together by hydrogen bonding. Thus, hydrogen bonding is crucial to the structure of the DNA molecule. 

Hydrogen bonding is vital for forming DNA's double helix structure and impacts proteins' 3D shapes. It's not involved in direct carbon-oxygen bonds or in causing van der Waals interactions, and contrary to decreasing it, hydrogen bonding actually increases water's boiling point.

Hydrogen bonding is necessary for forming double-stranded DNA molecules. It occurs when hydrogen forms a polar covalent bond, gaining a slight positive charge that attracts it to the negative charge on more electronegative atoms like oxygen or nitrogen. This interaction is fundamental in DNA, where hydrogen bonds between complementary nucleotides hold the strands together, and in proteins, where they influence the three-dimensional structure.

Hydrogen bonding contributes to the high boiling point of water (100 0C). Importantly, hydrogen bonds are not involved in bonding carbon to oxygen directly - those are typically covalent bonds - nor do they cause van der Waals interactions or decrease the boiling point of liquids; in fact, they generally increase it due to the additional energy required to break these bonds.

Hydrogen bonds and van der Waals interactions are both types of weak intermolecular forces, with the former playing a critical role in the structure and function of biological macromolecules such as DNA and proteins.

A container filled with gas is connected to an open-end manometer that is filled with mineral oil. the pressure in the gas container is 753 mm hg and atmospheric pressure is 724 mm. how high will the level rise in the manometer if the densities of hg and mineral oil are 13.6 g/ml and 0.822 g/ml respectively?

Answers

To calculate the height mineral oil will rise in a manometer to balance a pressure difference of 29 mm Hg, we use the ratio of densities between mercury and mineral oil. The mineral oil level will rise approximately 479.82 mm to balance the pressure difference.

To find out how high the level will rise in the manometer when it is filled with mineral oil instead of mercury, we must first understand the relationship between pressure, height, and density in a manometer. Given that the pressure of the gas is 753 mm Hg and atmospheric pressure is 724 mm Hg, the pressure difference that the mineral oil needs to balance is the pressure of the gas minus the atmospheric pressure (753 mm Hg - 724 mm Hg = 29 mm Hg).

Since mercury has a density of 13.6 g/ml, the same pressure difference can be formulated in terms of the mineral oil by using the following ratio:

Pressure difference in terms of mercury (mm Hg) = Pressure difference in terms of mineral oil (height in mm) * (Density of mineral oil / Density of mercury)

Substituting the given density values:

29 mm Hg = height in mm × (0.822 g/ml / 13.6 g/ml)

height in mm = 29 mm Hg / (0.822 g/ml / 13.6 g/ml)

height in mm = 29 mm Hg × (13.6 g/ml / 0.822 g/ml)

height in mm = 29 mm Hg × (13.6 / 0.822)

height in mm = 29 mm Hg × 16.5455

height in mm = 479.82 mm

The level of mineral oil in the manometer will rise approximately 479.82 mm to balance the pressure difference.

To find the height mineral oil will rise in the manometer, calculate the pressure difference between the gas and atmosphere, convert it to mercury's equivalent, and then find the corresponding height in mineral oil based on its density. The mineral oil level will rise approximately 479.8 mm in the manometer.

The student is asking about the rise in mineral oil level in an open-end manometer connected to a gas container when the pressure inside the container and the atmospheric pressure are known. To find the height that the mineral oil would rise in the manometer, we need to equalize the pressures exerted by the mineral oil and mercury (Hg), given that the mercury pressure is 753 mmHg and the atmospheric pressure is 724 mmHg.

First, we calculate the pressure difference the gas is exerting over atmospheric pressure:

Pressure difference = Pressure of gas - Atmospheric pressurePressure difference = 753 mmHg - 724 mmHgPressure difference = 29 mmHg

Next, we convert this pressure difference to the equivalent height of mineral oil, using the densities provided:

Height in mineral oil = (Pressure difference in mmHg * Density of Hg) / Density of mineral oilHeight in mineral oil = (29 mmHg * 13.6 g/ml) / 0.822 g/mlHeight in mineral oil = (394.4 g/ml) / 0.822 g/mlHeight in mineral oil = 479.8 mm

So, the mineral oil level will rise approximately 479.8 mm in the open-end manometer.

The diagram shows the movement of particles from one end of the container to the opposite end of the container.



Which event is most likely occurring?
diffusion because particles move from regions of high concentration to regions of low concentration
diffusion because particles move from regions of low concentration to regions of high concentration
effusion because there is a movement of a gas through a small opening into a larger volume
effusion because there is a movement of a gas through a large opening into a smaller volume

Answers

Answer:
diffusion because particles move from regions of high concentration to regions of low concentration.

Difusión refers to the movement of the particles through a material. The driven force  for the diffusion is the gradient (difference) of concentration.

Diffusion, for example, is what happens if you open a bottle of perfume in a corner of your bedroom and later the smell fills all the room. The particles will spread along all the space until the concentration of the perfume in uniform.

if a balloon containing 12.2L of gas at 298K is heated so the balloon expands to 17.4L, what is the final temperature if the pressure remains constant?

Answers

Data:

Volume 1, V1 = 12.2 liter
Temperature 1, T 1= 298 K
Volume 2, V2 = 17.4 liter
Temperature 2, T2 = ?
Pressure: constante

Formula:

V1 / T1 = V2 / T2

Solution:

T2 = V2 * T1 / V1 = 17.4 liter * 298 K / 12.2 liter

=> T2 = 425 K

Answer: 425 K

Consider a 1260-kg automobile clocked by law-enforcement radar at a speed of 85.5 km/h. If the position of the car is known to within 2.0 m at the time of the measurement, what is the uncertainty in the velocity of the car?

Answers

The expected speed is v = 85.5 km/h
 v = 85.5 km/h = (85.5 km/h)*(0.2778 (m/s)/(km/h)) = 23.75 m/s

If there is an uncertainty of 2 meters in measuring the position, then within a 1-second time interval:
The lower measurement for the speed is v₁ = 21.75 m/s,
The upper measurement for the speed is v₂ = 25.75 m/s.
The range of variation is
Δv = v₂ - v₁ = 4 m/s

The uncertainty in measuring the speed is
Δv/v = 4/23.75 = 0.1684 = 16.84%

Answer: 16.8%

How many moles of cobalt atoms are there in 6.00x10^9 Co atoms?

Answers

6.00x10^9 Co atoms / 6.022x10^23 Co atoms = 9.96x10^-15 moles of Co

Which of these properties is the best one to use for identification of an element?
the number of neutrons in the atomic nucleus
the number of protons in the atomic nucleus
the number of isotopes that are formed by the element
the number of charges on ions of the element

Answers

Answer:

B

Explanation:

Number of protons in the atomic nucleus

The number of protons in the atomic nucleus  is the best one to use for identification of an element. Therefore, the correct option is option B.

An element is a chemical compound which can be changed into another chemical component. The amount of protons in the atoms' nucleus, the basic building block of a chemical element, allows us to distinguish between different chemical elements.

Most of the baryonic material in the universe is composed of chemical components. When different elements undergo chemical reactions, particles get rearranged into new compounds that are held together by chemical bonds. The number of protons in the atomic nucleus  is the best one to use for identification of an element.

Therefore, the correct option is option B.

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Which of the following is a branch of chemistry? biology microbiology all of the above none of the above biophysics

Answers

There are five main branches of chemistry including, physical, analytical, biochemistry, organic and inorganic chemistry. I would have to say that the answer to this question is none of the above. The answers given to this multiple choice question are some of the branches of biology. If the question asked for the branches of biology then the answer would be all of the above.

Problem 5.32 - enhanced - with feedback the rolling resistance for steel on steel is quite low; the coefficient of rolling friction is typically μr=0.002. suppose a 180,000 kg locomotive is rolling at 22 m/s on level rails. you may want to review ( pages 138 - 142) . part a if the engineer disengages the engine, how much time will it take the locomotive to coast to a stop?

Answers

The frictional force can be calculate as:

Ff = μr * N

where μr is the frictional constant while N is the normal force which is also equivalent to weight, hence:

Ff = 0.002 * 180,000 kg * 9.81 m/s^2

Ff = 3,531.6 N

 

The frictional force is also equivalent to the product of mass and acceleration, so we can find a:

Ff = m * a

a = 3,531.6 N / 180,000 kg

a = 0.01962 m/s^2 (in negative direction)

 

We can solve for time using the formula:

v = vi + a t

where v is final velocity = 0, vi is initial velocity = 22 m/s, t is time

0 = 22 - 0.01962 * t

t = 1,121.3 seconds

A complete circuit contains two parallel-connected devices and a generator for providing the
electromotive force. The resistance of the first device is 12 ohms, the resistance of the second device is 4
ohms, and the voltage developed by the generator is 40 V. What is the magnitude of the current flowing
through the first device?
A. 10 A
B. 13.32 A
C. 8 A
D. 3.33 A

Answers

Parallel circuits are circuits when placed in a parallel position. Meaning that for each device, they have their own branch. The voltage that is received in the circuit is equal to the individual devices. The total current is equal to the current of each device. The resistance is the reciprocal of the resistances of each device combined.  

Given:
Device 1 = 12 ohms
Device 2 = 4 ohms
Voltage total = 40V  

Required:
Current at 12 ohms  

Solution:
40V = V1 =V2  

Since V =IR
I1 = V1/R1
I1 = (40V)/(12 ohms)
I1 = 3.334 A(Amperes)

The following chemical reaction takes place in aqueous solution: 2FeBr3 (aq) + 3Na2S (aq) → Fe2S3 (s) + 6NaBr (aq) Write the net ionic equation for this reaction.

Answers

net ionic equation simply means to cancel out any ions which appear on both sides of the chemical equation that are not involved in the reaction - they're called spectator ions
We'll first write out the full ionic equation, showing all ions and compounds formed, then rewrite and not include spectator ions.

2FeBr3(aq) + 3Na2S(Aq) --> Fe2S3(s) + 6NaBr(aq)   [original eqation]

2Fe3+(aq) + 6Br-(aq) + 3Na+(aq) + 3S2-(aq)--> Fe2S3(s)+6Na+(aq) + 6Br-(aq)
[full ionic equation]

2Fe3+(aq) + 3S2-(aq)--> Fe2S3(s)   [net ionic equation]

notice that Br- and Na+ appear unreacted on both sides of the full ionic equation, so they cancel out and do not appear in the net ionic.

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Final answer:

In the reaction given, the net ionic equation is derived by removing the spectator ions, resulting in the net ionic equation: 2Fe3+ (aq) + 3S2- (aq) → Fe2S3 (s).

Explanation:

The net ionic equation is derived by eliminating the spectator ions from the total ionic equation. The first step is to break all the strong electrolytes into their ions. In the reaction 2FeBr3 (aq) + 3Na2S (aq) → Fe2S3 (s) + 6NaBr (aq), we have the following ions:

2Fe3+ (aq) + 6Br- (aq)6Na+ (aq) + 3S2- (aq)

These combine to form Fe2S3 (s) and 6Na+ (aq) + 6Br- (aq). The ions that appear on both sides of the equation are the spectator ions (Na+ and Br-), and we can remove them to get the net ionic equation:

2Fe3+ (aq) + 3S2- (aq) → Fe2S3 (s)

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At 1.00 atm and 0 °c, a 5.04 l mixture of methane (ch4) and propane (c3h8) was burned, producing 19.4 g of co2. what was the mole fraction of each gas in the mixture? assume complete combustion.

Answers

First, we will use the ideal gas law to determine the number of moles of the mixture that was present.

n = PV/RT

n = 1 * 5.04 / 0.082 * (273.15 + 0)
n = 0.225 moles


Let the moles of propane be P and the moles of methane be M.


P + M = 0.225

Next, we find the moles of carbon dioxide formed:

Moles = mass / Molecular weight
Moles = 19.4 / 44 = 0.441

Each mole of propane produces 3 moles of carbon dioxide and each mole of methane produces one mole of carbon dioxide. So:

3P + M = 0.441

Subtracting the first equation from the second, we get:

2P = 0.216
P = 0.108 moles

M = 0.225 - 0.108
M = 0.117

Fraction of propane = 0.108/0.225 = 0.48
Fraction of methane = 0.52

Final answer:

To find the mole fraction of each gas in the mixture, calculate the number of moles of methane and propane using the Ideal Gas Law. Then, divide the moles of each gas by the total moles to find the mole fraction.

Explanation:

To find the mole fraction of each gas in the mixture, we need to first calculate the number of moles of methane and propane in the mixture. From the given information, we know that the mixture has a volume of 5.04 L. Using the Ideal Gas Law, we can calculate the number of moles of each gas:

Methane (CH4):

1 mole of gas at STP (Standard Temperature and Pressure) occupies 22.4 L

Molar mass of methane (CH4) = 12.01 g/mol + (4 * 1.008 g/mol) = 16.04 g/mol

Number of moles of methane = (5.04 L / 22.4 L) * (19.4 g / 16.04 g/mol) = 0.454 moles

Propane (C3H8):

1 mole of gas at STP occupies 22.4 L

Molar mass of propane (C3H8) = (3 * 12.01 g/mol) + (8 * 1.008 g/mol) = 44.11 g/mol

Number of moles of propane = (5.04 L / 22.4 L) * (19.4 g / 44.11 g/mol) = 0.469 moles

Now, to find the mole fraction of each gas:

Mole fraction of methane = moles of methane / total moles of gas = 0.454 / (0.454 + 0.469) ≈ 0.492

Mole fraction of propane = moles of propane / total moles of gas = 0.469 / (0.454 + 0.469) ≈ 0.508

Which of the following elements is the most reactive?    A. Arsenic (As)    B. Sulfur (S)    C. Fluorine (F)    D. Carbon (C)

Answers

im not that smart but i think it c

Final answer:

Fluorine (F) is the most reactive among the elements listed. It is part of the halogen group (Group 17) and is the most reactive nonmetal due to its high electronegativity.

Explanation:

Among the given elements, Fluorine (F) is the most reactive. Reactivity varies across the periodic table, but generally, elements in the same group (vertical column) have similar chemical characteristics. Fluorine sits in Group 17 and is the lightest member of the halogen group which makes it the most reactive nonmetal, because it has the greatest electronegativity of all the elements and thus is very eager to gain an extra electron. Compare that to Arsenic (As), Sulfur (S), and Carbon (C) which are significantly less reactive than Fluorine.

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Which statement is true according to the quantum model of the atom?

Answers

A, when it drops down from a high energy level...
When an electron drops down from a high energy level to a lower one, light energy is emitted.

The most common cooling mechanism for cloud formation is ________.

Answers

The answer is "Rising and expanding air or atmosphere cooling".
To form a cloud the air must be cooled to the temperature of dew point. when there is expansion of air, it cools to the dew point and thus the formation of cloud happens. This process is very common and used for the formation of clouds.

What is the absorbance of the permanganate in the diluted waste solution?

Answers

Not to be confused with tetration. This article is about volumetric titration. For other uses, see Titration (disambiguation). Acid–base titration is a quantitative analysis of concentration of an unknown acid or base solution. Titration, also known as titrimetry,[1] is a common laboratory method of quantitative chemical analysis that is used to determine the unknown concentration of an identified analyte. Since volume measurements play a key role in titration, it is also known as volumetric analysis. A reagent, called the titrant or titrator[2] is prepared as a standard solution. A known concentration and volume of titrant reacts with a solution of analyte or titrand[3] to determine concentration. The volume of titrant reacted is called titration volume

How many grams of chlorine gas must react to give 3.52g of BiCl3 according to the equation in exercise 23?
2Bi+3Cl2---->2BiCl3

Answers

3.52g BiCl3 × 1 mol BiCl3/ 315.34g BiCl3 × 3 mol Cl/ 2 mol BiCl3 × 70.906g Cl/ 1 mol Cl= 1.187 g Cl

The correct answer is 1.19 g of chlorine.

The following reaction is:

2Bi (s) + 3Cl₂ (g) ⇒ 2BiCl₃ (s)

In the reaction, it can be witnessed that 3 mol Cl₂ is equal to 2 mol BiCl₃

The molecular weight of BiCl₃ = 315.33

Thus,

3.52 g BiCl₃ = 3.52 g BiCl₃ × 1.00 mol BiCl₃ / 315.33 g BiCl₃

= 0.0112 mol BiCl₃

The mole ratio of Cl₂ and BiCl₃ is,

3 mol Cl₂ / 2 mol BiCl₃

Therefore, the amount of chlorine needed to form 0.0112 mol BiCl₃ is,

0.0112 mol BiCl₃ × 3 mol Cl₂ / 2 mol BiCl₃ = 0.0168 mol Cl₂

Now, the molecular weight of Cl₂ = 70.90

Thus,

0.0168 mol Cl₂ = 0.0168 mol Cl₂ × 70.90 g Cl₂ / 1.00 mol Cl₂

= 1.19 gm Cl₂

Hence, in the mentioned reaction, there is a need of 1.19 g of chlorine to react to produce 3.52 g of BiCl₃.

Nai(aq)+hg2(no3)2(aq)→ express your answer as a chemical equation. identify all of the phases in your answer. enter noreaction if no precipitate is formed.

Answers

Final answer:

Mercury(II) nitrate and Sodium iodide don't react with each other in water, so no precipitate is formed. If a reaction were to occur, it would be a double displacement reaction, like the example provided.

Explanation:

The student is asking to write a balanced chemical equation for the reaction between Sodium iodide (NaI) and Mercury(II) nitrate (Hg(NO3)2). However, these two substances do not react with each other, because both of them are soluble in water. Thus, there will be no precipitate formed, and the answer is no reaction. Nevertheless, it is essential to take note that if these ions were to react to form a precipitate, a double displacement reaction would occur, similar to example: Ba(OH)2 (aq) + 2HNO3(aq) → Ba(NO3)2(aq) + 2H₂O(1), where water and a salt are formed as the products.

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The reaction between NaI(aq) and Hg₂(NO₃)₂(aq) results in the formation of NaNO₃(aq) and a precipitate, Hg₂I₂(s). This confirms that a reaction occurs. The balanced chemical equation is provided with phases identified.

The reaction between sodium iodide (NaI) and mercury(I) nitrate (Hg₂(NO₃)₂) in aqueous solutions can be described using the chemical equation:

2NaI(aq) + Hg₂(NO₃)₂(aq) → 2NaNO₃(aq) + Hg₂I₂(s)

In this reaction, the products include aqueous sodium nitrate (NaNO₃) and a precipitate of mercury(I) iodide (Hg₂I₂). Therefore, a precipitate is formed, and the reaction proceeds.

HURRRRRRRRRRRY 50 PNTSSS


How many grams of Hydrogen (H) would need to react with 190 grams of Fluorine (F) to make 200 grams of HF (Hydrofluoric Acid)?

Answers

I think 10 i'm not entirely sure

Each degree on the Kelvin scale equals:
1°C
10°C
no relationship (different scale)
100°C

Answers

A change of 1 Kelvin is exactly the same as a change of 1 degree Celsius.

Answer is: 1°C.

A change of 1 Kelvin is the same as a change of 1 degree Celsius.

The temperature T in degrees Celsius (°C) is equal to the temperature T in Kelvin (K) minus 273,15: T(°C) = T(K) - 273.15.

For example:

T(He) = 4,2 K.

T(He) = 4,2 K - 273,15.

T(He) = -268,95°C.

The Celsius scale was based on 0°C for the freezing point of water and 100°C for the boiling point of water at 1 atm pressure.


A 4.36 g sample of an unknown alkali metal hydroxide is dissolved in 100.0 ml of water. an acid-base indicator is added and the resulting solution is titrated with 2.50 m hcl (aq) solution. the indicator changes color signaling that the equivalent point has been reached after 17.0 ml of the hydrochloric acid solution has been added. (a) what is the molar mass of the metal hydroxide? (b) what is the identity of the metal cation?

Answers

Answer:

(a) [tex]102.6g/mol[/tex]

(b) Rubidium

Explanation:

Hello,

This titration is carried out by assuming that the volume of base doesn't have a significant change when the mass is added, thus, we state the following data a apply the down below formula to compute the molarity of the base solution:

[tex]V_{base}=0.1L; M_{acid}=2.5M, V_{acid}=0.017L\\V_{base}M_{base}=V_{acid}M_{acid}[/tex]

Solving for the molarity of base we've got:

[tex]M_{base}=\frac{M_{acid}*V_{acid}}{V_{base}}=\frac{2.50M*0.017L}{0.1L} =0.425M=0.425mol/L[/tex]

Now, we can compute the moles of the base as:

[tex]n_{base}=0.425mol/L*0.1L=0.0425mol[/tex]

(a) Now, one divides the provided mass over the previously computed moles to get the molecular mass of the unknown base:

[tex]\frac{4.36g}{0.0425mol} =102.6g/mol[/tex]

(b) Subtracting the atomic mass of oxygen and hydrogen, the metal's atomic mass turns out into:

[tex]102.6g/mol-16g/mol-1g/mol=85.6g/mol[/tex]

So, that atomic mass dovetails to the Rubidium's atomic mass.

Best regards.

When a connector is marked with "al-cu," the connector is suitable for use with copper, copper-clad aluminum, and aluminum conductors?

Answers

The statement given is True. The connectors marked with AL-Cu can be used with copper, copper clad cadmium and aluminum conductors.

Connectors are used to perform different functions that is to connect or disconnect the path of an electric current.

Wire connectors which are used to connect copper-clad aluminum conductors to copper conductors should be rated for copper and aluminum (“CUAL” or “AL-CU”) connections or rated for copper to aluminum, intermixed (terminated in the same twist-on connector), and in direct physical contact.

CU is used with copper only, AL with aluminum wire only, AL-CU can be used with aluminum, copper and, copper-clad cadmium.

Hence, the answer is true. The connectors marked with AL-Cu can be used with copper, copper clad cadmium and aluminum conductors.

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Final answer:

An 'AL-CU' designation on a connector signifies that it is safe for use with copper, copper-clad aluminum, and aluminum conductors. These connectors are essential for effective conductivity in a variety of electrical systems.

Explanation:

Yes, a connector marked with 'AL-CU' is indeed suitable for use with copper, copper-clad aluminum, and aluminum conductors. This designation means that the connector has been specifically designed and tested for safe use with these types of electrical conductors. These connectors ensure safe and effective conductivity and are, therefore, vital components in many electrical appliances and systems.

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Find the total number of atoms in a sample of cocaine hydrochloride, c17h22clno4, of mass 20.5 mg .

Answers

Final answer:

The total number of atoms in a 20.5 mg sample of cocaine hydrochloride (C17H22ClNO4) is approximately 1.83 × [tex]10^2^1[/tex] atoms, calculated by determining the number of moles in the sample first and then using Avogadro's number to find the number of molecules and atoms.

Explanation:

To find the total number of atoms in a 20.5 mg sample of cocaine hydrochloride (C17H22ClNO4), you first need to calculate the number of moles in the sample and then use Avogadro's number to convert it to the number of molecules, and finally multiply by the total atoms in one molecule of the compound.

First, calculate the molar mass of cocaine hydrochloride:
C (12.01 g/mol) × 17 + H (1.01 g/mol) × 22 + Cl (35.45 g/mol) × 1 + N (14.01 g/mol) × 1 + O (16.00 g/mol) × 4 = 303.36 g/mol

Next, determine the number of moles in the 20.5 mg sample:
20.5 mg × (1 g / 1000 mg) / 303.36 g/mol = 6.76 × [tex]10^-^5[/tex] moles

Now, utilizing Avogadro's number (6.02 × 10^23 molecules/mol), calculate the number of molecules in the sample:
6.76 × 10^-5 moles × 6.02 × 10^23 molecules/mol = 4.07 × [tex]10^1^9[/tex] molecules

Since each molecule of cocaine hydrochloride contains 45 atoms (17 C + 22 H + 1 Cl + 1 N + 4 O), multiply the number of molecules by the number of atoms per molecule:
4.07 × [tex]10^1^9[/tex] molecules × 45 atoms/molecule = 1.83 × [tex]10^2^1[/tex] atoms

Therefore, a 20.5 mg sample of cocaine hydrochloride contains approximately 1.83 × [tex]10^2^1[/tex] atoms.

Arrange the following in order of increasing boiling point: RbF, CO2, CH3OH, CH3Br. Explain your reasoning.

Answers

The following is the order from lowest boiling point to highest based on the types of forces these compounds have: CO2 CH3Br CH3OH RbF CO2 is a nonpolar molecular compound. The only intermolecular force present is a relatively weak dispersion force, because of the small molar mass. CO2 will have the lowest boiling point. ď‚· CH3Br is a polar molecule. Dispersion forces (present in all matter) and dipoleâ’dipole forces will be present. This compound has the next highest boiling point. ď‚· CH3OH is a polar molecule, which can form hydrogen bonds; these are especially strong dipole-dipole attractions. Dispersion forces and hydrogen bonding are present to give this substance the next highest boiling point. ď‚· RbF is an ionic compound. Ionâ’ion attractions are much stronger than any intermolecular force. RbF has the highest boiling point

We can arrange the given compound in order of increasing boiling point as CO2 <CH3Br <CH3OH <RbF.

The compound with the highest boiling point is RbF, since it has the strongest intermolecular force.

CH3OH, CH3Br can doesn't posses strong intermolecular force compare to RbF, and they can form hydrogen bond.

CO2 can form weak dispersion force and it's a non polar compound and it posses the boiling point.

What is boiling point?

This is the temperature at whereby the vapor pressure of a liquid equals the pressure.

At this temperature, the liquid changes into a vapor and the weaker the force of attraction the lower the boiling point.

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How many grams of naoh are needed to prepare 500 ml of 0.125 m naoh?

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First let us calculate for the number of moles needed:

moles NaOH = 0.125 M * 0.500 L = 0.0625 mol

 

The molar mass of NaOH is 40 g/mol, hence the mass is:

mass NaOH = 0.0625 mol * 40 g/mol

mass NaOH = 2.5 grams

To prepare the solution of  500 ml of 0.125 m NaOH, the mass of 2.5 g of sodium hydroxide is required.

What is the molarity?

The concentration of the solution can be calculated if we have the molecular formula and molecular weight. We can easily calculate the concentration of a substance in a solution.

The molarity of a solution can be determined from the number of moles of a solute in a liter of a solution.

The Molarity of the solution is determined in the following way.

Molarity (M) = Moles of solute (n)/Volume of the Solution ( in L)

Given, the molarity of NaOH solution = 0.125 M

The volume of the NaOH solution, V = 500 ml = 0.5 L

The number of moles of NaOH = 0.125 × 0.5 = 0.0625 mol

The mass of the NaOH is required = 0.0625 ×40 =2.5 g

Therefore, 2.5 grams of NaOH are needed to prepare 500 ml of 0.125 m NaOH.

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Solid potassium hydroxide koh decomposes into gaseous water and solid potassium oxide . write a balanced chemical equation for this reaction.

Answers

Answer:

2KOH(s) ---> K2O(s) + H2O(g)

Explanation:

potassium hydroxide = KOH

water = H2O

potassium oxide = K2O

since KOH decomposes into H2O and K2O there is an arrow after KOH then after that you balance it. Without doing anything, KOH ----> H2O + K2O on the left side of the arrow there is only one K, one O, and one H atoms while on the other side there are 2 H, 2O, and 2K which means we have to put the two in front of the KOH. so then you will have 2K, 2O, 2H on the left-handed side which will equal the number of atoms there are on the right-handed side.

Also dont forget to put whether it is g, s, or aq.

In the instructions it tells you which one is s , g, or aq.

Final answer:

The balanced chemical equation for the decomposition of solid potassium hydroxide (KOH) into solid potassium oxide (K2O) and gaseous water (H2O) is: 4 KOH(s) → 2 K2O(s) + 2 H2O(g).

Explanation:

The balanced chemical equation for the decomposition of solid potassium hydroxide (KOH) into gaseous water (H2O) and solid potassium oxide (K2O) is:

4 KOH(s) → 2 K2O(s) + 2 H2O(g)

This reaction showcases the breakdown of potassium hydroxide into simpler substances when it decomposes. Notice that the total number of atoms for each element is conserved on both sides of the equation, fulfilling the Law of Conservation of Mass.

if 15.0 g of a solid dry ice (Co2) is placed into an evacuated 5.00 L container and allowed sublime until it is entirely in the gas phase, what pressure (in atm) will the gas exert at 299 K?

Answers

Data:

mass, m = 15.0 grams

Molecule = CO2

volume, V = 5.00 liter

temperature, T = 298 K

pressure, P = ?

Formulas:

PV = nRT

n = m / molar mass

Solution:

molar mass of CO2 = 44.01 g/mol

n = 15.0 g / 44.01 g/mol = 0.3408 mol

P = nRT / V = 0.3408 mol * 0.0821 atm*liter/K*mol * 299K / 5.00 liter

P = 1.67 Pa

Answer: P = 1.67 Pa
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