If the boiling point of ethanol went up 6. 8 degrees, how many grams of PbCl4 were added to 2700 grams of ethanol? round to nearest tenth

i) The possible event that the sample is undergoing at 232°C is melting and it can be measured using the DSC technique.

ii) If the sample is now cooled from 270 °C to room temperature, the DSC curve would show a reversed peak at 232°C as compared to the heating curve.

i. The possible event that the sample is undergoing at 232°C is melting and it can be measured using the DSC technique because Differential Scanning Calorimetry (DSC) is used to determine the amount of energy absorbed or released by a sample when heated or cooled under controlled conditions. It measures the heat flow, which is the difference in the amount of heat required to heat a sample and a reference (inert) material as a function of temperature.

When a material undergoes a phase change, it absorbs or releases heat, which is detected by DSC. The technique provides information about the thermal behavior of the material.

ii. If the sample is now cooled from 270 °C to room temperature, the DSC curve would show a reversed peak at 232°C as compared to the heating curve.

This is because the enthalpy of fusion during the cooling process will be released to the environment (surroundings) as heat. Thus, the peak will be negative as the material releases heat rather than absorbing it.

Additionally, there will be no other peaks as the material is cooling from a higher temperature to a lower temperature and no phase changes occur during the cooling process.

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The volume of the ethane sample at STP will be 27.6 L given that volume of the sample at 440 torr and 29°C is 2.98 L.

STP means Standard Temperature and Pressure. The standard temperature is 273 K and the standard pressure is 1 atm or 760 torr.1 atm = 760 torr1 L at STP = 22.4 L at 440 torr and 29°C

The volume of a sample of ethane at STP can be calculated as follows:

PV = nRTAt 440 torr and 29°C:V1 = 2.98 L, P1 = 440 torr, T1 = 29°C + 273 = 302 K

At STP:V2 = ?, P2 = 1 atm, T2 = 273 K

From the ideal gas law:

PV = nRTFor both the initial and final states, the number of moles remains the same.n1 = n2Let's substitute all the values.P1V1/T1 = P2V2/T2

We are solving for V2.V2 = (P1V1T2)/(P2T1)V2 = (440 torr × 2.98 L × 273 K)/(1 atm × 302 K)V2 = 27.6 L

The volume of the ethane sample at STP will be 27.6 L.

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Answer:

The answer will be false.

Explanation:

because it is not balanced.

Answer:

Explanation:

The volume of the inner cylinder = πr^2h

                                             = π*4*18

                                            = 72π

The volume of the big cylinder= πr^2h

                                                  = π*16*18

                                                  = 288π

The volume of the cone= \(\frac{1}{3}\) πr^2h

                                       = 1/3 * π*16*5

                                      = 1/3*80π

The total volume= 1/3*80π - 72π+288π

                           = 1/3*80π+116π

                           = (80+348)π/3

                           = 428π/3

                          = 428 * 3.14/3

                         = 1343.92/3

                         =447.9733cubic inches

the mistake that the student might have done is adding the whole volume of the cylinder without subtracting the volume of the hollow.

Answer:

Watson and Crick were also aided in their discovery by Maurice Wilkins (1916-2004) and Rosalind Franklin (1920-1958). Franklin had taken X-ray photographs of DNA that her colleague, Wilkins, showed to Watson

Explanation:

Answer:

Rosalind Franklin. She discovered DNA as a double helix form. But men got jealous of her and stole her work just because she is a woman. How cruel! That's why there is something called feminism in this world.  

Explanation:

Hope it helped!

The change in color might indicating the formation of a new product. Hence, the color change indicates a chemical change.

A chemical change involves the breaking/ making or both of chemical bonds. Chemical changes results in formation of new products that have different properties and structure from the initial substances.

A physical change include change in size, shape, state etc. All phase changes such as melting, boiling, freezing are physical changes. Evolution or absorption of heat, conductivity, solubility etc are physical changes.

A change in color indicates that a new product with different color is formed in the system. Therefore, option c color change indicates a chemical change.

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Answer:

boiling water

Explanation:

its hotter

Answer:

There is nothing with data to help us complete this chart

THIS IS BAD. THIS IS REALLY BAD

The increase in temperature of the embedded bullet is approximately 112.6 °C.

We will find the increase in temperature of the embedded bullet using the given mass, speed, specific heat, and energy conversion factors.
- Mass of the bullet (m) = 3.00 g = 0.003 kg (convert grams to kilograms)
- Speed of the bullet (v) = 240 m/s
- Specific heat of lead (c) = 0.0305 kcal/kg×°C = 0.0305 × 4186 J/kg×°C (convert kcal to Joules)
- Half of the heat energy remains with the bullet

1. Calculate the initial kinetic energy (KE) of the bullet using the formula KE = 1/2 × m × v²
2. Divide the initial KE by 2 to find the heat energy absorbed by the bullet
3. Use the heat energy (Q), mass (m), and specific heat (c) to calculate the increase in temperature (ΔT) using the formula Q = m × c × ΔT

Now let's calculate:

1. KE = 1/2 × 0.003 kg × (240 m/s)² = 86.4 J
2. Heat energy absorbed by the bullet = 86.4 J / 2 = 43.2 J
3. 43.2 J = 0.003 kg × (0.0305 × 4186) J/kg×°C × ΔT

Solving for ΔT:

ΔT = 43.2 J / (0.003 kg × 127.673 J/kg×°C) ≈ 112.6 °C

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1.chloride

2.sulfate

3.ferric

4.bromide

5.binary

6.ammonium

7.nirate

8.fluroide

give me brainliest as per your question ok

Answer:

6; barium sulfate

7; chromium (III) carbonate

The mass, in grams, of the sample of methanol (CH₃OH) is 64 grams.

Mass of any substance can be calculated by using moles as:

n = W/M, where

W = required mass

M = molar mass

In the question that:

Moles of methanol = 2mole

Molar mass of methanol = 32g/mole

On putting these values in the above equation, we get

W = n × M

W = 2mole × 32g/mole = 64g

Hence, 64 grams is the mass of the sample.

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Answer:

C. 17

Explanation:

The question above is related to the "Periodic Table of Elements." The Halogen group is located on the right side of the table. It consists of six elements: Fluorine, Chlorine, Bromine, Iodine, Astatine and Tennessine.

The "atomic number" of an element refers to the number of protons that can be found in the element's nucleus. Among the halogens, "Chlorine" is the only one with an atomic number of 17. Halogens do not have an atomic number of 10, 136 and 13.

Answer:

1.2 cm^3

Explanation:

5.74 grams of a something occupies a volume of 1.2 cm^3 .

In electrolysis the flow of electrons occurs from Anode (Positively Charged electrode) towards Cathode (Negatively charged electrode).

Therefore Diagram A shows the correct flow of electron in an electrolysis

Chemical decomposition produced by passing an electric current through a Electrolytic (Salt) solution containing ions.

Anode is located at the left hand side of the electrolytic cell where as cathode is located at the right hand side of the electrolytic cell.  

Therefore, In the given diagrams, Diagram A follows the above mentioned pattern.

Hence, It shows the correct direction of electron flow in an electrolytic cell.

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Answer:

The second student is right.

Explanation:

The coyote feed on not only phalaropes but many other organisms present in the environment for its survival. There are many other organisms present in the ecosystem such as mice, squirrel, cactus fruit etc. The coyote feeds on phalaropes, the phalaropes feeds on brine shrimp and the brine shrimp feeds on algae for its survival so in this way the ecosystem moves in the forward direction. The coyote feeds on phalaropes so the energy that is present in phalaropes transferred into coyote which only 10 % while the remaining is released in the atmosphere in the form of heat energy.

When exposed to atmospheric oxygen and salt water, aluminum will react to form aluminum oxide which causes bumps and depressions (pitting) on the aluminum surface. This is an example of corrosion.

Corrosion is the destruction of materials by chemical and/or electrochemical reactions with their environment. Corrosion of metals is a major problem in all industries. The chemical reaction results in the formation of metal oxides or salts. It's a natural process that reduces the durability of metal parts and materials. When exposed to atmospheric oxygen and saltwater, aluminum will corrode and form aluminum oxide. As a result, the surface of the aluminum will be pitted. Corrosion of aluminum can be prevented by using coatings such as paints, powder coatings, or anodizing, as well as by avoiding exposure to saltwater. In general, corrosion prevention is an important consideration for the longevity of equipment, structures, and components.

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A. only volume (cm³) is the independent variable

B. both volume (cm³) and mass (grams) are independent variable

C. not enough information

D. the slope of the trend line

E. only mass (grams) is the independent variable

Answer:

the independent variable

Explanation:

just took the test

The density (density equals mass divided by volume) and percent error of aluminum would be 2.64g/ml and 2.59% respectively.

Percent error is a way to express the difference between a measured value and the true value of a quantity as a percentage. It is commonly used in science and engineering to quantify the degree of accuracy or error in a measurement or calculation. The formula for percent error is:

(Experimental value - actual value| / actual value) x 100%

Density is mass divided by volume, so the density of the aluminum pellets is:

12.8 g / 4.85 mL = 2.64 g/m

To find the percent error, we can use the formula:

(Experimental value - actual value| / actual value) x 100%

Placing in the values, we get:

(2.64 g/mL - 2.71 g/mL| / 2.71 g/mL) x 100% = 2.59%

So, the density of the aluminum pellets is 2.64 g/mL and the percent error is 2.59%.

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The mass of the silver sample is approximately 77.9 grams.

To solve this problem, we can utilize the equation for heat transfer:

q = m * c * ΔT

where q represents the heat transferred, m is the mass of the substance, c is the specific heat capacity, and ΔT is the change in temperature.

Initially, we calculate the heat transferred from the silver to the water:

q silver = m silver * c silver * ΔT silver

q water = m water * c water * ΔT water

For thermal equilibrium between the silver and water, we equate the two equations as they reach the same temperature:

q silver = q water

m silver * c silver * ΔT silver = m water * c water * ΔT water

Rearranging the equation allows us to solve for the mass of the silver:

m silver = (m water * c water * ΔT water) / (c silver * ΔT silver)

Substituting the given values:

m silver = (250g * 4.184 J/g°C * (23.35°C - 6.5°C)) / (0.235 J/g°C * (98.75°C - 23.35°C))

As a result:

m silver = 77.9 g

Thus, the mass of the silver sample is approximately 77.9 grams.

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Answer:

Alkylation reaction help in formation of thiol R-SH

Say lets take sodium hydrosulfide (NaSH) and alkyl chloride (R-Cl)/ any acid like chloroaceic acid or choloro or potassim acetates.

R-Cl + NaSH --> R-SH + NaCl

Such reactions are seen in the production of paper from wood pulp and in the production of organic compounds like thioglycolic acids (TGA)

Answer:

temperature

Explanation:

The initial pH of a 25.00 mL sample of 0.340 M KOH titrated with 0.750 M HI at 25 °C can be calculated by considering the reaction between KOH and HI. The titration involves the neutralization of a strong base (KOH) with a strong acid (HI). Before any titrant is added, the solution consists of only KOH. KOH is a strong base that dissociates completely in water, releasing hydroxide ions (OH⁻). Since OH⁻ is a basic species, the initial pH can be calculated by using the pOH equation and converting it to pH.  The initial pH of the 25.00 mL sample of 0.340 M KOH before any titrant is added is approximately 11.93.

In the case of KOH, it dissociates into K⁺ and OH⁻ ions. The initial concentration of OH⁻ ions can be calculated by multiplying the volume of the solution (25.00 mL, which is equivalent to 0.02500 L) by the molarity of KOH (0.340 M). This gives us 0.0085 moles of OH⁻ ions. As the volume of the solution is known, we can directly calculate the pOH using the equation pOH = -log[OH⁻]. Plugging in the value, we have pOH = -log(0.0085) ≈ 2.07. To find the initial pH, we subtract the pOH from 14 (since pH + pOH = 14), giving us an initial pH of approximately 11.93.

Therefore, the initial pH of the 25.00 mL sample of 0.340 M KOH before any titrant is added is approximately 11.93. This pH is calculated by considering the concentration of hydroxide ions (OH⁻) in the solution, which arises from the complete dissociation of KOH. By applying the pOH equation and converting it to pH, we determine that the concentration of OH⁻ ions results in a pOH value of approximately 2.07. Subtracting the pOH from 14, we find the initial pH to be approximately 11.93.

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The pH of the resulting mixture is approximately 4.73. Option C is correct.

Lactic acid is a weak acid and will react with NaOH to form a salt, sodium lactate, and water.

The balanced equation for the reaction is;

C₃H₆O₃ + NaOH → C₃H₅O₃Na + H₂O

The initial concentrations of lactic acid and NaOH are;

[HA] = 0.2 M x 0.055 L = 0.011 mol

[OH⁻] = 0.1 M x 0.1 L = 0.01 mol

Since NaOH is strong base, it will completely dissociate in water to produce OH⁻ ions.

The reaction between lactic acid and NaOH can be treated as a buffer solution. The pH of the buffer solution can be calculated using Henderson-Hasselbalch equation;

pH = pKa + log([A⁻]/[HA])

where pKa is dissociation constant of the weak acid, [A⁻] is concentration of the conjugate base, and [HA] is concentration of the weak acid.

In this case, the conjugate base is sodium lactate (C₃H₅O₃Na) and the weak acid is lactic acid (C₃H₆O₃). The concentration of the conjugate base can be calculated from the amount of NaOH that reacts with lactic acid;

[Na⁺]= [OH⁻] = 0.01 mol

[A⁻] = 0.01 mol/0.055 L = 0.182 M

Therefore,

pH = pKa + log([A⁻]/[HA])

pH = 3.86 + log(0.182/0.011)

pH = 4.73

Therefore, the pH is 4.73.

Hence, C. is the correct option.

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Answer:

The liquid state sometimes is described simply as the state that occurs between the solid and gaseous states. Some examples of liquids are:

- Water

- Milk

- Vinegar

Unlike a liquid, a solid object does not flow to take on the shape of its container, nor does it expand to fill the entire available volume like a gas. Some examples of solids are:

- Rocks

- Brick

- Coin

What distinguishes a gas from liquids and solids is the vast separation of the individual gas particles. This separation usually makes a colorless gas invisible to the human observer. Some examples of gases are:

- Helium

- Oxygen

- Neon

Answer:

9

Explanation:

neutrons = atomic mass - atomic number

neutrons = 15 - 6

Answer:

U A G C C A U C G G A U C C G A U

Explanation:

In DNA, A=T, C=G, and vice versa. RNA has U instead of T. So dna to rna: adenine = uracil, thymine = adenine, cytosine = guanine, and guanine = cytosine.

The three components of light Nature combines the soft, scattered light from the sky with the vibrant, focused light from the sun. Units are Candela, Lumen, Lux.

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The final value for the enthalpy of reaction used for the intermediate reaction would be -572 kJ. Option D is correct.

If we need to multiply a reaction by a certain factor in a Hess's law problem, we also need to multiply the enthalpy change (ΔH) by the same factor to maintain the same stoichiometry. In this case, we need to multiply the given reaction by 2 to use it as an intermediate reaction.

The balanced equation after multiplying by 2 would be:

2H₂ + O₂ → 2H₂O

The enthalpy change (ΔH) for this reaction would be:

ΔH = 2(-286 kJ/mol) = -572 kJ/mol

Therefore, the final value for the enthalpy of reaction used for the intermediate reaction would be -572 kJ. Option D is correct.

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Answer:

Acceleration is defined as the rate of change of velocity. ... For a particular interval, the average acceleration is defined as the change in velocity for that particular interval. Unlike acceleration, the average acceleration is calculated for a given interval.