Two identical blocks are heated to different temperatures. The blocks are placed so that they touch, and heat begins to flow between the blocks. The pair of blocks is insulated, so no energy escapes. Later, the temperature of each block is measured again. Which pair of temperatures is possible.
PLEASE HURRY.

Volume of the 0.45 m solution of HCl would just to neutralize 210 ml of a solution containing 4.7 g of the Ba(OH)₂ is 0.12 L.

The reaction is given as :

2HCl(aq)   + Ba(OH)₂(aq)   --->   BaCl₂(aq)   +   2H₂O

1 mole of Ba(OH)₂ react with the 2 mole HCl

Molarity of  HCl, C1 = 0.45 M

Volume of HCl, V1 =.?

The mass of  Ba(OH)₂ = 4.7 g

Moles = mass / molar mass

Moles = 4.7 / 171.34

Moles = 0.027 mol

The moles of HCl = 2 × 0.027

                             = 0.054 mol

Volume = moles / molarity

Volume = 0.054 / 0.45

Volume = 0.12 L

To learn more about volume here

https://brainly.com/question/17277081

#SPJ4

A phylogenetic tree constructed from gene sequence data is based on similarities in, the correct option is (D) nucleotide substitutions in homologous genes.

Phylogenetic tree are constructed from gene sequence data by comparing the sequences of homologous genes (genes that have a similar function and evolutionary origin) from different organisms. The similarities and differences in the nucleotide sequences of these genes are used to infer evolutionary relationships among the organisms. The tree is built based on the principle of common descent, which states that organisms that share a common ancestor will have more similar gene sequences than those that do not. By comparing the sequence similarities and differences, it is possible to infer the evolutionary relationships among different organisms and construct a branching diagram, known as a phylogenetic tree, that illustrates these relationships.

To know more about phylogenetic tree please refer: https://brainly.com/question/13577065

#SPJ4

Among the compounds listed, a) CH3CH2F has the lowest intermolecular forces, meaning it has the lowest boiling point.

This is because the fluorine atom has the smallest atomic radius, meaning it has the weakest dipole-dipole interactions.

The other compounds (CH3CH2NH2, CH3CH2CH2OH, CH3CH(OH)CH3, and CH3CH2COOH) all have higher boiling points due to the fact that they have larger atomic radii, resulting in stronger dipole-dipole interactions.

This is because the fluorine atom is the smallest in size and has the strongest intermolecular force, thus giving it the lowest boiling point.

To learn more about boiling point, click here:

https://brainly.com/question/2153588

#SPJ4

An elimination reaction having two possible reaction mechanisms i.e, E₁ and E₂ mechanisms.

It is a type of reaction which is mainly used to transform saturated compounds (organic compounds which contains only single C-C bonds) to unsaturated compounds (compounds which feature double or triple carbon-carbon bonds).

Mechanism of elimination reaction: 1) Removal of proton 2) Formation of C-C pi bond 3) Removal of leaving group.

E₁-Reaction: It s also known as unimolecular elimination, They are having two steps-ionization and deprotonation. During the ionization, there is a formation of carbocation as an intermediate. In deprotonation, a proton will be lost by the carbocation. This will happen in the presence of a base which further leads to the formation of a pi-bond in the molecule. It exhibits first-order kinetics.

E₂-Reaction:  E₂ mechanism refers to bimolecular elimination which is basically a one-step mechanism. Here, the C-H as well as carbon-halogen bonds mostly break off to form a new double bond. However, in E₂ mechanism, a base is the part of the rate-determining step. The reaction rate is mostly proportional to the concentrations of both the eliminating agent as well as the substrate. It exhibits second-order kinetics.

To know more about E₂-Reaction here

https://brainly.com/question/28239179

#SPJ4

Strategy:

Use the mole ratio and find the number of moles of oxygen formed by 6 moles of potassium chlorate. 6 moles of KClO3 (735.3 grams of KClO3) produce 9 moles of O2 gas. Technically, this is the theoretical yield, but the answer becomes more useful when you convert moles to grams.

Answer: Caesium

Explanation:

Caesium has the lowest ionization energy. With the lowest ionization energy, it is the one that will most easily give up electrons.

Answer: cesium

Explanation:(cs)

The balanced equation for the reaction is: 2 NH3 + 3 CuO ---> 3 Cu + 3 H2O + N2, when 42 moles of CuO are consumed, 14 moles of N2 can be made.

From this equation, we can see that for every 3 moles of CuO that are consumed, 1 mole of N2 is produced.

To find the number of moles of N2 that can be made when 42 moles of CuO are consumed, we can use the stoichiometry of the reaction. We can use the following formula:

moles of product = moles of reactant x (moles of product / moles of reactant)

In this case, we can use the following equation to find the number of moles of N2 that can be produced:

= moles of N2

= 42 moles x (1 mole N2 / 3 moles CuO)

= 14 moles of N2

So, when 42 moles of CuO are consumed, 14 moles of N2 can be made.

To know more about moles please refer: https://brainly.com/question/26416088

#SPJ4

The theoretical value for the temperature increase would be negligible, as the reaction between hydrochloric acid (HCl) and sodium hydroxide (NaOH) is exothermic but also dilute.

When HCl and NaOH are mixed together, they react to form water and salt (sodium chloride). This reaction is exothermic reaction, which means it releases heat. However, because the solutions are dilute (1.0 M), the amount of heat released will be small and may not be measurable. Additionally, the heat released during the reaction would be quickly dissipated due to the small volume of the solutions. Thus, the theoretical temperature increase would be negligible.

To learn more about exothermic reaction visit: https://brainly.com/question/24808802

#SPJ4

Your question seems incomplete, but I suppose the question was:

"we mixed 30 ml of 1.0 m hcl with 70 ml of 1.0 m naoh. what is the theoretical value for the temperature increase?"

For a first order reaction, the time taken to reduce the initial concentration by a factor of 1/4 is 10 min.

calculate the time it takes for the concentration of ab to reduce to 1/4 of its original concentration?

To learn more about concentration   refers to:

https://brainly.com/question/17206790

#SPJ4

Carbon dioxide and methane are the atmospheric gases which absorbs more than one type of electromagnetic radiations or light.

The electromagnetic radiation consists of waves made up of electromagnetic field which are capable of propogating through space and carry the radiant electromagnetic energy.

The radiation are composed of electromagnetic waves which are synchronized oscillations of electric and magnetic fields . They are created due to change which is periodic in electric as well as magnetic fields.

In vacuum ,all the electromagnetic waves travel at the same speed that is with the speed of air.The position of an electromagnetic wave in an electromagnetic spectrum is characterized by it's frequency or wavelength.

Learn more about electromagnetic radiation,here:

https://brainly.com/question/10759891

#SPJ1

Answer:

Hummingbird

Explanation:

A hummingbird’s long, curved bill (or beak) is perfectly designed to sip the nectar deep inside trumpet-shaped flowers. In fact, the types of flowers a species will visit are closely tied to the shape of the birds’ beaks. Long, narrow flowers, for instance, are visited by hummers with equally long bills.

During the light reactions water is oxidized to O2. hydrogen go to Used in the reduction of NADP+.

The photolysis process, sometimes referred to as the light reaction, occurs when light is present. Typically, it occurs in the chloroplasts' grana. Pigment molecules are present in photosystems. One of the key pigments in plants that actively participates in light-related processes like photosynthesis is chlorophyll. In the chloroplast of the mesophyll cells of the leaves, a light-dependent process takes place. The stacked disc-like structures known as thylakoids make up the double-membraned cell organelles known as chloroplasts. The membrane of these thylakoids contains the pigment chlorophyll, which is necessary for the process and is where the light reaction takes place.

learn more about molecules Refer:brainly.com/question/29755819

#SPJ4

The solvents used to generate this and only this product are DMF, DMSO, i-PrOH.

1-bromopropane reacts with sodium propan-2-olate to form 1-isopropoxypropane. The mechanism of this reaction follows SN2 pathway.

Polar aprotic solvents like DMF, DMSO favors SN2 reaction and provides an ease to carry the reaction.

If the nucleophile is dissolve in less polar solvent, then SN2 reaction goes faster to form required product.

The nucleophile sodium propan-2-olate is dissolve in less polar solvent i-propanol (i-PrOH).

Thus, the solvents used to generate the only product are shown below:

DMF (dimethyl formamide)

i-PrOH (iso-propanol)

DMSO (dimethyl sulfoxide)

The synthesis reaction is given in the image.

Learn more about solvents from the link given below.

https://brainly.com/question/25988535

#SPJ4

Give an example of where a scientist might be: a. accurate but not precise. b. precise but not accurate. c. both precise and accurate, are listed below.

What is accurate?

Accuracy is the measure of how closely a measurement resembles the actual or accepted value. How closely two measurements of the same thing differ is referred to as precision.

What is precise?

The precision of an object is defined as the similarity between two or more measurements. If you weigh an object five times and it weighs 2 kg each time, the measurement has precision but not necessarily accuracy, or it might be the other way around.

Therefore, Give an example of where a scientist might be: a. accurate but not precise. b. precise but not accurate. c. both precise and accurate, are listed below.

Learn more about accurate from the given link.

https://brainly.com/question/1695072

#SPJ1

a. Accurate but not precise:

An example of a scientist being accurate but not precise could be a situation where a scientist measures the boiling point of a substance and obtains a series of measurements consistently close to the accepted value but with a wide range of variation among the measurements. Although the measurements may not be precise (due to the variability), they are accurate because they are close to the true value.

b. Precise but not accurate:

An example of a scientist being precise but not accurate could be a scenario where a scientist uses a faulty instrument to measure the length of an object. The measurements obtained may consistently show the same value (high precision) but differ significantly from the actual length (low accuracy). In this case, the measurements are precise (consistent) but not accurate (far from the true value).

c. Both precise and accurate:

An example of a scientist being both precise and accurate could be a situation where a scientist measures the weight of an object using a highly calibrated and accurate weighing scale. The scientist obtains several measurements that are all very close to each other (high precision) and also very close to the true weight of the object (high accuracy). In this case, the measurements are both precise and accurate, indicating a high level of reliability and validity.

learn more about Accurate here:

https://brainly.com/question/30350489

#SPJ11

2.5 moles pf pb3O4 are produced from 1.25 moles of oxygen

The reaction is shown below.

6PBo+ O2------> 2 PB3O4

here 1 mole of O2(oxygen) -----> 2 moles PB3O4

1 for 1.2 moles of O2------> ?(x)

x= 1.2* 2/ 1

x= 2.5 moles of PB3O4

As the amount of reactants increases, the molecular distance between the reacting particles decreases, increasing the likelihood of subsequent collisions. The four key variables that influence reaction rate are reactant concentration, the reactants' physical state, surface area, temperature, and the presence of a catalyst. The disproportionately significant increase in the frequency of high energy collisions causes an increase in reaction rates as temperature rises.

Learn more about oxygen here:

https://brainly.com/question/13370320

#SPJ4

The Gibbs free energy ΔG for the following chemical reaction:

6Cl2 + P4 -> 4PCl3 is 82.764kJ

Given the pressure of chlorine gas (P1) = 1.32atm = 1.32 x 10^5Pa

The pressure of phosphorous gas (P2) = 7.56atm = 7.56 x 10^5Pa

The pressure of phosphorous trichloride (P3) = 3.30atm = 3.30x10^5Pa

The temperature of vessel containing these gases (T) = 25°C = 298K

We know that from Gibbs equation ∆ = ∆° + () here R is the universal gas constant = 8.314

∆ = ∆° + (P3^4/P1^6 x P2)

For equilibrium condition ∆ = 0

So,  ∆° = (P3^4/P1^6 x P2)

∆°  = -8.314x298 x 2.303 x log[(3.30x10^5)^4/(1.32 x 10^5)^6(7.56 x 10^5)]

∆° = -5.7 x 10^3log[118.5/39.91x10^15]

∆° = -5.7 x 10^3 x log[2.96/10^15]

∆° = -5.7 x 10^3 x (-14.52)

∆° = 82.764 x 10^3 = 82.764kJ

Hence the required Gibbs free energy is 82.764kJ

To learn more about Gibbs free energy click here https://brainly.com/question/20358734

#SPJ4

Answer:

there are approximately 5.5 x 10^23 molecules in 16.5 grams of water

Explanation:

To calculate the number of molecules in a certain mass of a substance, you need to know the molar mass of the substance and convert the mass to moles.

The molar mass of water is 18.015 g/mol. To convert the mass of water to moles, we can use the equation:

moles = mass / molar mass

So, moles of water = 16.5 g / 18.015 g/mol = 0.916 mol

Avogadro's number is 6.022x10^23. To calculate the number of molecules, we can multiply Avogadro's number by the number of moles.

So the number of molecules = (6.022x10^23) * (0.916 mol) = 5.5x10^23 molecules

Therefore, there are approximately 5.5 x 10^23 molecules in 16.5 grams of water

The mass of water in the calorimeter is 7.98 g when The temperature of the water is increased from 21. 7˚C to 56. 4˚C.

We can use the equation Q = mcΔT to calculate the heat transfer between the lead and the water.

Q is the heat transfer, m is the mass of the substance, c is the specific heat of the substance, and ΔT is the change in temperature.

The heat absorbed by the water is equal to the heat lost by the lead, so we can set the two heat transfer equations equal to each other:

Qwater = Qlead

mwater * cwater * ΔTwater = mlead * clead * ΔTlead

where mwater is the mass of the water, cwater is the specific heat of water (4.184 J/g°C), ΔTwater is the change in temperature of the water, mlead is the mass of the lead (200.0 g), and ΔTlead is the change in temperature of the lead (176.4°C - 21.7°C = 154.7°C)

We can solve for mwater by isolating it on one side of the equation:

mwater = (mlead * clead * ΔTlead) / (cwater * ΔTwater)

mwater = (200.0 g * 0.129 J/g°C * 154.7°C) / (4.184 J/g°C * 35.7°C)

mwater = 7.98 g

So the mass of water in the calorimeter is 7.98 g.

Learn more about mass here:

https://brainly.com/question/17067547

#SPJ4

The solubility product constant (Ksp) of calcium sulfate (CaSO4) and the idea of ion product may be used to determine the solubility of calcium sulfate (CaSO4) in 0.30 M aqueous sodium sulfate.

(Na2SO4). The calcium ion (Ca2+) concentration in the solution. may be estimated as follows: [Ca2+][SO42-] = Ksp [Ca2+][SO42-] = 2.0 x 10^-5 When there is sodium sulfate present, part of the sulfate ions will originate from the sodium sulfate rather than the calcium sulfate. The total sulfate ion concentration (SO42-) in the solution may be determined as follows [SO42-] = [Na2SO4] + [CaSO4] + x = 0.30 M (where x is the concentration of CaSO4) When we enter the values into the Ksp expression, we get: 2.0 x 10^-5 = [Ca2+] [0.30 M + x] x [0.30 M + x] = [Ca2+] x [0.30 M + x] [Ca2+] = (2.0 x 10^-5) / (0.30 M + x) We may substitute [Ca2+] in the Ksp equation since [Ca2+] = [CaSO4]: ([CaSO4])2 / (0.30 M + [CaSO4]) = 2.0 x 10-5 This equation may be solved for [CaSO4,] which yields the calcium sulfate solubility in 0.30 M aqueous sodium sulfate solution.

learn more about solubility  here:

https://brainly.com/question/29661360

#SPJ4

In a reaction of an acid that has an equal amount of a base, the ph changes to a value that is closer to 7 or neutral .

Any solution is considered "neutral" and has a pH of 7 if there is an equal quantity of acid and base present. Because the pH of the neutralised substance is close to or equal to 7, when an acid combines with a base, acid and water are produced. The autoprotolysis reaction, the next equilibrium, serves as the foundation for acid-base behaviour in water.

Reactions to neutralisation, when a strong acid and a strong base are mixed together in the right amounts, [H+] equals [OH], creating a neutral solution with pH of 7, the outcome is. Acidic and basic qualities are no longer existent because the acid and base have neutralised one another. When acid and base are together, a neutralisation reaction occurs where salt and water are created.

For such more questions on pH :

brainly.com/question/2288405

#SPJ4

The  reactant is in excess 2Mg + O2 → 2MgO 4.8 g Mg ≡ 0.2 mole 3.2 g O2 ≡ 0.1 mole.

What is the limiting reactant?

To learn more about reactant refers to:

https://brainly.com/question/6421464

#SPJ1

The reactants that are in excess 2Mg + O2 → 2MgO 4.8 g Mg ≡ 0.2 mol 3.2 g O2 ≡ 0.1 mol.

To learn more about limiting reactant from the given link:

https://brainly.com/question/14225536

#SPJ1

Answer:

The average atomic mass of element X is 68.719 amu

Step-by-step explanation:

1. To determine the average atomic mass of element X, the atomic masses and abundances of its isotopes must be used.

2. The atomic mass of the first isotope is 68 amu, the second isotope is 69 amu, and the third isotope is 70 amu.

3. To calculate the average atomic mass, the formula is used: Average Atomic Mass = (68amu x 0.565) + (69amu x 0.234) + (70amu x 0.201)

4. Applying the formula, the average atomic mass of element X is 68.719 amu.

The statements wrong about cathode rays is none of the given option. All the given option is true about the cathode rays.

The statements for the cathode rays is given as :

A. They travel in straight lines towards cathode. This statement is true about the cathode rays.

B. They produce heating effect. This statement is true about the cathode rays.

C. They carry negative charge. This statement is true about the cathode rays.

D. They produce X-rays when strike with material having high atomic masses. This statement is true about the cathode rays.

Thus, none of the option is incorrect about the cathode rays.

To learn more about cathode rays here

https://brainly.com/question/26500956

#SPJ4

The atmospheric pressure on the surface of Venus is 6.84 × 10⁴ mmHg in atm and torr is :

The atmospheric pressure is given as:

Atmospheric pressure = 6.84 × 10⁴ mmHg

1 atm (atmospheric pressure) =  101325 pascal (Pa).

To convert the mmHg to atm , divide the pressure value by 101325.

Pressure in atm  = 0.67 atm

1 Torr is equals to 133.322 Pa. divide the pressure value by 133.322 to convert it in torr.

Pressure in Torr =513.0 Torr

Thus, pressure in atm is 0.67 atm and the pressure in torr is 513 torr.

To learn more about pressure here

https://brainly.com/question/14104793

#SPJ4

Answer: It is described as a solvent

Explanation: I hope this helps!

Answer:

Air dissolved in the water escapes in the form of tiny bubbles because the sun was giving heat energy to the bottle.

Explanation:

When water is boiled, the heat energy is transferred to the molecules of water, which begin to move more quickly. Eventually, the molecules have too much energy to stay connected as a liquid. When this occurs, they form gaseous molecules of water vapor, which float to the surface as bubbles and travel into the air.

The value of rate constant is  3.33 x 10^-11 cm3/molecules-s. To determine the order of the reaction with respect to oxygen atoms, we can use the data collected in the first set of experiments.

Where NO2 was in large excess. We can use the method of initial rates, where we compare the rates of the reaction at different initial concentrations of O.  From the data, we can see that

at t = 1.0 x 10^-2 s, [O] = 1.9 x 10^9 atoms/cm3 and

the rate is k[O]^x[NO2]

, where x is the order of the reaction with respect to O.

At t = 2.0 x 10^-2 s,

[O] = 6.8 x 10^8 atoms/cm3 and

the rate is k[O]^x[NO2].

At t = 3.0 x 10^-2 s,

[O] = 2.5 x 10^8 atoms/cm3 and

the rate is k[O]^x[NO2].

Since the order of the reaction with respect to O is x. for

(b), the reaction is known to be first order with respect to NO2,

so the overall rate law is rate = k[NO2].

To determine the value of the rate constant, we can use the integrated rate law, which is -[O] = kt + [O]0,

Where [O] is the concentration of O at time t,

k is the rate constant and

[O]0 is the initial concentration of O.

Using the data from the first experiment

where t = 3.0 x 10^-2 s and

O] = 2.5 x 10^8 atoms/cm3,

the value of k. -2.5 x 10^8 = k * 3 x 10^-2 + 5 x 10^9.

Solving for k, we get k = 3.33 x 10^-11 cm3/molecules-s.

Learn more about rate law here:

https://brainly.com/question/20309887

#SPJ4

Russian chemist Dmitri Mendeleev wrote down the symbols for the chemical elements on February 17, 1869, arranged them in numerical order based on their atomic weights.

and created the modern periodic table. One of history's most illustrious scientists, the Russian chemist Dmitri  Mendeleev, passed away 100 years ago this year (1834–1907). His invention of the periodic table in 1869 was a major accomplishment that serves as both a helpful mnemonic and a tool for organizing all of chemistry. The elements were organized by Mendeleev in ascending order of relative atomic mass. He observed a periodic tendency in the chemical characteristics of the elements and their compounds as he performed this.There were no openings for newly found elements in his eight groupings of the elements. The structure for the contemporary periodic table was developed in 1869 by Russian scientist Dmitri Mendeleev, who left spaces for elements that had not yet been identified.

learn more about Dmitri Mendeleev  here:

https://brainly.com/question/1888686

#SPJ4

Natural fission can take place and generate more stable nuclei than the original nucleus.

When a neutron collides with a bigger atom, it causes it to excite and fragment into two smaller atoms, which are known as fission products. Additionally, additional neutrons are emitted, and these can start a chain reaction.

There is a great amount of energy produced when each atom divides.

Uranium and plutonium are most frequently employed in nuclear power reactors.

Fission is a nuclear reaction in which splitting of a nucleus into two daughter nuclei takes place.

Nucleus is the central positive body of the atom that consists of neutrons and protons.

Neutron is a subatomic particle with zero charge which is present in the nucleus of the atom.

A nuclear power reactor is a device that is used to initiate and control a nuclear fusion reaction chain.

To know more about protons :

https://brainly.com/question/12535409

#SPJ1

Yes, an Olympic swimmer to need more food energy every day than we do.

Why do swimmers need energy?

Swimmers need energy to fuel their bodies for intense physical activity. Swimming is an anaerobic and aerobic exercise, both of which require energy to be used efficiently. Swimmers typically need to consume carbohydrates before and during their workouts for sustained energy, as well as protein to help their muscles repair and rebuild. Eating a balanced diet that is high in carbohydrates and proteins will help swimmers stay energized and perform their best.

An Olympic swimmer would need more food energy every day than the average person because they need more energy to train and compete. Swimming is an intense physical activity that requires a lot of energy and endurance. Olympic swimmers must swim for hours each day, working hard to reach their peak performance. As a result, they would need more food energy to fuel their bodies for the strenuous physical activity.

Therefore, an Olympic swimmer to need more food energy every day than we do.

To learn more about swimmers from the link

https://brainly.com/question/17319163

#SPJ1