Aluminum + oxygen yields aluminum oxide Write a balanced equation for this chemical reaction. A) Al + O → AlO B) Al + O → Al2O3 C) 2Al + 3O2 → Al2O3 D) 4Al + 3O2 → 2Al2O3

Answer:

25.33125KPa

Explanation:

From the above,

1atm = 101.325KPa

0.25atm = (0.25atm x 101.325KPa) / 1atm = 25.33125KPa

Therefore, 0.25atm = 25.33125KPa

Answer:

Explanation:

When the variable adds out and the final sentence is false you have arrived to a contradiction, also called absurd, meaning that the starting equality was a wrong assumption that could never be true. Thus, the equation has no solutions.

An example of such situation is this equation:

To solve it, you use the subtraction property of the equalities: subtract both x and 3 from both sides:

The variable added out and the final sentences 0 = 6 is false. That means that none value of x satisfies the original equation and it has no solutions.

Answer:

It has 0 solutions

Explanation:

Answer: E. they enable enzymes to bind to their substrates.

Explanation:

The cofactors are the molecules that help the enzyme catalyze the reactions. The Cofactor can be defined as a non-protein chemical compound that either loosely or tightly binds to the enzyme. This facilitates in performing the reactions that enzyme cannot perform alone. They can be  divided into prosthetic group and coenzymes. The cofactors enhances the binding affinity of the enzymes with their substrates so that products can be formed.

Answer:

The answer is E: they enable enzymes to bind to their substrates.

Explanation:

Cofactors are inorganic substrates that are needed to: 1) produce a chemical reaction between the enzyme and the substrate, 2) increase the rate of catalysis, and 3) attach to the enzyme just like a prosthetic hand, to effectively allow enzymes carry out the catalysis of the reaction.

Isotopes are versions of a chemical element with different neutron numbers. Examples are Hydrogen-1, 2, and 3. Non-examples would be different elemental atoms.

Isotopes are variants of a particular chemical element which differ in neutron number, and consequently in nucleon number. All isotopes of a given element have the same number of protons but different numbers of neutrons in each atom.

Examples of isotopes include Hydrogen-1 (Protium), Hydrogen-2 (Deuterium), and Hydrogen-3 (Tritium) - all are isotopes of hydrogen but have different numbers of neutrons. Non-examples of isotopes would be atoms of different elements, like a helium atom (2 protons) compared with a hydrogen atom (1 proton).

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Water, having the highest specific heat of 4.18 J/g·°C among the substances listed, would be the best at maintaining its heat over time, making it the most suitable to keep warm during a long football game on a cold night.

The specific heat value of a substance is key for understanding which material would maintain heat longer. Based on the specific heat values provided, water, with a specific heat of 4.18 J/g·°C, would be the best at maintaining its heat through a long football game on a cold night. This is because the higher the specific heat, the more energy (heat) the substance can store and the longer it can release that heat over time, compared to substances with lower specific heats like copper, lead, or glass.

Answer:

Potential energy of reactants in an endothermic reaction is lower than the potential energy of products because in endothermic reaction system absorb energy from  environment. We can see that in the lower temperature of environment after completed reaction.

Explanation:

The potential energy of products is less than the potential energy of the reactants.

Exothermic reactions are defined as the reactions which release heat. The release in heat is due to the difference in the potential energy of the reactants and the products.

[tex]$\Delta H_{r x n}=\sum H_{\text {products }}-\sum H_{\text {reactants }}$[/tex]

An exothermic reaction [tex]$\Delta H_{r x n}$[/tex] is negative.

For the reaction of baking soda and vinegar, the equation follows:

[tex]$\mathrm{NaHCO}_{3}+\mathrm{CH}_{3} \mathrm{COOH} \rightarrow \mathrm{CH}_{3} \mathrm{COONa}+\mathrm{CO}_{2}+\mathrm{H}_{2} \mathrm{O}+$[/tex]

As the energy is written at the product side, this means that the reaction between baking soda and vinegar is an exothermic reaction.

Learn more about endothermic reaction

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Answer:

The solution are in the explanation below

Explanation:

- Find the melting point of authentic sample of pure A.

- Mix sample A into both vials.

- Use melting point depression

- Lower melting component will liquefy first, and melting point will lower/broaden the range. (Determine which vial holds sample B mixed with A)

- Vial with the same sample A melting point range would remain consistent to 102-104˚C.

Johnny can identify the unknown samples A and B by conducting a melting point analysis with a mixture of the unknown and a known authentic sample of A. A unchanged melting point indicates the unknown is A, while a changed range suggests it is B. Proper technique is necessary for accurate results.

Johnny should perform a melting point analysis to determine which vial contains which substance. He can take a small amount of the authentic sample of pure A and mix it with a small amount of the unknown substance. He should then measure the melting point range of the mixture. If the mixture has a sharp, unchanged melting point range similar to the authentic sample's known value, it can be concluded that the unknown substance is also substance A. If the melting point range is depressed or broadened, it indicates the unknown substance is not A, but rather substance B.

It is important to note that if the expected melting point is not known, the substance should be heated at a medium rate to determine an approximate melting point. A second attempt should be made with a fresh sample for accuracy. Additionally, ensuring that the amount of solvent is suitable for the volume of the flask, and that heat is properly trapped can guarantee optimal re-crystallization conditions.

Answer:

D

Explanation:

The answer is D- There are more collisions of air molecules against the wall of the balloon.

Squeezing an air-filled balloon increases the number of collisions of air molecules with the wall of the balloon, leading to more pressure inside and potentially a higher temperature.

When you squeeze an air-filled balloon, the correct answer is D. There are more collisions of air molecules against the wall of the balloon. This is because squeezing the balloon increases the pressure inside it as the volume available to the gas molecules is reduced. Given a constant amount of gas, compressing it makes the molecules collide more frequently with the walls of the balloon. According to the principles of kinetic molecular theory, increased pressure results from an increased number of collisions. This can raise the temperature inside the balloon, as suggested by the relationship described in Charles's Law, which states that volume and temperature are directly proportional when the pressure is held constant. However, if the pressure increases due to compression, this does not necessarily indicate a change in temperature, as that depends on energy transfer, which is not specified in the scenario. Instead, it is the frequency of molecular collisions that increases.

Answer:

The answer to your question is volume = 0.47 ml

Explanation:

To solve this problem use the formula of density, that relates the mass and volume.

Data

density = 19.3 g/ml

mass = 9.0 g

volume = ?

Formula

density = [tex]\frac{mass}{volume}[/tex]

Solve for volume

volume = [tex]\frac{mass}{density}[/tex]

Substitution

Volume = 9 / 19,3

Simplification and result

Volume = 0.47 ml

Final answer:

To determine the volume a 9.00 g piece of gold occupies, divide the mass of gold by its density (19.3g/mL), which calculates to approximately 0.4663 mL.

Explanation:

The question asks to find the volume occupied by a 9.00 g piece of gold, given that the density of gold is 19.3g/mL. To find the volume, we use the formula density = mass/volume, which can be rearranged to find volume as volume = mass/density.

Given:

Mass of gold = 9.00 g

Density of gold = 19.3 g/mL

Applying the values into the formula gives

volume = 9.00 g / 19.3 g/mL

, which equals approximately 0.4663 mL.

Therefore, a 9.00 g piece of gold will occupy about 0.4663 milliliters.

Answer: The heat of hydration for potassium nitrate is 708.8 kJ/mol

Explanation:

We are given:

Heat of solution for potassium nitrate = 23.8 kJ/mol

Lattice energy for potassium nitrate = -685.0 kJ/mol

Heat of hydration for potassium nitrate = ?

To calculate the heat of hydration, we use the equation:

Heat of the solution = Heat of hydration + Lattice energy

Putting values in above equation, we get:

[tex]23.8=\text{Heat of hydration}+(-685.0)\\\\\text{Heat of hydration}=23.8-(-685.0)\\\\\text{Heat of hydration}=708.8kJ/mol[/tex]

Hence, the heat of hydration for potassium nitrate is 708.8 kJ/mol

The correct answer would be C, a

chemical change.

Answer:

Rise

Explanation:

Because the cargo has no place to go it will make the water level rise

Volume of the gas is 525 L.

Explanation:

It is given that the volume of the gas divided by the temperature is 1.75.

V/T = 1.75

As per the Charles law, volume is proportional to the temperature.

V ∝ T

V/T = constant

Now we have to find V, and T is given as 300 K.

So plugin the values as,

V/300 = 1.75

Rearranging the equation to get V as,

V = 1.75×300

  = 525 L

Answer : The volume required to administer a 75 mcg dose are, 0.75 mL

Explanation : Given,

Concentration of Digoxin = 0.1 mg/mL

That means, 0.1 mg of Digoxin present in 1 mL of solution.

Mass of dose = 75 mcg = 0.075 mg

Conversion used : (1 mcg = 0.001 mg)

Now we have to determine the volume required to administer a 75 mcg dose.

As, 0.1 mg of Digoxin required in 1 mL of solution

So, 0.075 mg of Digoxin required in [tex]\frac{0.075mg}{0.1mg}\times 1mL=0.75mL[/tex] of solution

Thus, the volume required to administer a 75 mcg dose are, 0.75 mL

Answer:

5.01×10^9 J is the energy required

Explanation:

This is a calorimetry problem:

Q = m . C . ΔΤ where:

Q = heat

m = mass

ΔΤ = Final T° - Initial T°

First of all we determine the pool's volume with the measures

10 m . 4m . 3m = 120m3

As water density is 1g/mL we can determine water's mass but firstly we must convert the m3 to cm3

1mL = 1cm3

1m3 = 1x10^6 cm3

120 m3 . 1x10^6 cm3 / 1m3 = 1.2x10^8 cm3

Water density = water mass / water volume

1 g/ mL = water mass / 1.2x10^8 mL

Water mass = 1.2x10^8 g

Then, we replace the data in the formula

Q = 1.2x10^8 g .4.18 J/g°C (30°C - 20°C)

Q = 1.2x10^8 g . 4.18 J/g°C . 10°C

Q = 5016000000 joules

5.01×10^9 J

Answer:

The specific heat capacity of the metal is lower than that of the water as explained as follows

Explanation:

The heat capacity is a measure of propensity of a given object or matter to undergo an increase or decrease in its temperature when subject a given amount of heat, in other words, for a given mass of the substance, it is the amount of heat required to be added to cause it to have a unit temperature change

The specific heat capacity of a material or substance is the amount of heat required to be supplied to raise the temperature of a unit mass of that by one degree Celsius. It is the ratio of the heat capacity of a specimen of a substance divided by the mass of the specimen

Both the water of the swimming pool, the swimmer and the metal chair are all exposed to the same amount of heat from the sun, however the heat required to raise the water temperture by one degree Celsius is higher than heat required to raise the temperature of the metal chair by one degree hence the chairs temperature is higher than the water temperature as shown in the following equation

ΔH = m₁ × C₁ × ΔT₁ = m₂ × C₂ × ΔT₂

Where ΔH =  Heat or energy supplied from the sun

m₁  = mass of water in the swimming pool

C₁  = Specific heat capacity of the water in the swimming pool

ΔT₁ = Change in temperature of the swimming pool and

m₂  = mass of metal chair

C₂  = Specific heat capacity of the metal chair material

ΔT₂ = Change in temperature of the metal chair

Where ΔH is the same for both the chair and swimming pool with the chair being hotter than the swimming pool with an asumed temperature change of 1.5 times that of the swimming pool and assuming the same mass of both the swimming pool and the chair are measured we have

m₁ × C₁ × 1.5ΔT₂ = m₁ × C₂ × ΔT₂ then cancelling like terms we have

1.5C₁ = C₂

Hence the heat capacity of the swimming pool water is 1.5 times that of the metal chair

On a hot sunny day, when you sit in a metal chair and it feels very hot, it indicates that the metal has a lower specific heat than water.

The specific heat of a material is a measure of the amount of heat energy required to raise the temperature of a given mass of the material by a certain amount. In this case, when you sit in a metal chair on a hot sunny day and it feels very hot, it indicates that the metal has a lower specific heat than that of water.

Metal is generally a good conductor of heat, which means it can rapidly transfer heat energy from the surroundings to your body when in contact. Water, on the other hand, has a higher specific heat and is a poor conductor of heat, so it takes longer to heat up and cool down.

The specific heat of metal depends on the type of metal. Different metals have different specific heat values.

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Answer : The heat absorbed by the ice cube and resulting water is, 9.15 kJ

Solution :

The process involved in this problem are :

[tex](1):H_2O(s)(-10.6^oC)\rightarrow H_2O(s)(0^oC)\\\\(2):H_2O(s)(0^oC)\rightarrow H_2O(l)(0^oC)\\\\(3):H_2O(l)(0^oC)\rightarrow H_2O(l)(29.0^oC)[/tex]

The expression used will be:

[tex]\Delta H=[m\times c_{p,s}\times (T_{final}-T_{initial})]+m\times \Delta H_{fusion}+[m\times c_{p,l}\times (T_{final}-T_{initial})][/tex]

where,

[tex]\Delta H[/tex] = heat available for the reaction = [tex]4.50\times 10^3kJ=4.50\times 10^6J[/tex]

m = mass of ice = 19.2 g

[tex]c_{p,s}[/tex] = specific heat of solid water or ice = [tex]2.01J/g^oC[/tex]

[tex]c_{p,l}[/tex] = specific heat of liquid water = [tex]4.18J/g^oC[/tex]

[tex]\Delta H_{fusion}[/tex] = enthalpy change for fusion = [tex]6.01kJ/mole=6010J/mole=\frac{6010J/mole}{18g/mole}J/g=333.89J/g[/tex]

Molar mass of water = 18 g/mole

Now put all the given values in the above expression, we get:

[tex]\Delta H=[19.2g\times 2.01J/g^oC\times (0-(-10.6))^oC]+19.2g\times 333.89J/g+[19.2g\times 4.18J/g^oC\times (29.0-0)^oC][/tex]

[tex]\Delta H=9147.1872J=9.15kJ[/tex]

Therefore, the heat absorbed by the ice cube and resulting water is, 9.15 kJ

Answer:

The rusting of the metal is a chemical change

Explanation:

Apparently, Rust is a product other than iron. Rusting is an example of a shift in chemistry. A chemical shift is also referred to as a chemical reaction which is a process that takes place as one or more compounds are converted into one or more different elements.

The formation of hydrated oxide, Fe(OH)3, FeO(OH), or even Fe2O3. H2O consists of the rusting of iron. It is an electrochemical phase requiring water, oxygen and an electrolyte to be present. No substantial rust occurs in the unavailability of any of these

The rusting of metal observed in Suisun Bay is a chemical change caused by a reaction between iron, oxygen, and water, forming iron oxides.

Rusting of metal is a chemical change. When you notice ships rusting in Suisun Bay, what's occurring is a chemical reaction between the iron in the metal and oxygen from the air, often accelerated by water, which leads to the formation of iron oxides. This process, known as oxidation, results in the deterioration of the metal's quality and its structural integrity.

To illustrate the concept further:

Answer:

a. Securities that have characteristics of both debt and equity

Explanation:

A convertible bond is a debt security that can be converted into a certain number of shares and this can be done during specific times in the life of the bond. According to this, convertible bonds are examples of securities that have characteristics of both debt and equity as they are a type of debt that pays interest but can be turned into shares.

Answer:

The velocity of the particle is 2 m/s,

Explanation:

Kinetic energy is defined as energy of the body due to its motion. It is given by :

[tex]K.E=\frac{1}{2}mv^2[/tex]

Where :

m = mass of the object

v = velocity of the object

We have , particle with mass m and its kinetic energy is twice its mass.

[tex]K.E=2m[/tex]

[tex]2m=\frac{1}{2}mv^2[/tex]

[tex]v^2=\frac{4}{1}[/tex]

[tex]v=2[/tex]

And unit of velocity are m/s , so the velocity of the particle is 2 m/s.

Final answer:

To find the velocity of a particle whose kinetic energy is twice its rest mass, we use relativistic mechanics and find that the velocity is approximately 0.943c. This indicates that relativistic effects are significant and must be considered.

Explanation:

When the kinetic energy (KE) of a particle is twice its rest mass energy (E0), relativistic calculations are needed due to the comparably large energy involved. The rest mass energy is given by the famous equation E0 = mc², where m represents the rest mass and c is the speed of light.

To find the velocity, we use the relativistic relationship between energy and velocity:

KE = (γ - 1)mc², where γ is the Lorentz factor, defined as γ = 1/ √(1 - v²/c²).

Given that KE is twice the rest mass energy (E0), it follows that:

2mc² = (γ - 1)mc²

We can cancel mc² on both sides and solve for γ:

2 = γ - 1 → γ = 3

Now, we can solve for v:

3 = 1/ √(1 - v²/c²)

√(1 - v²/c²) = 1/3

1 - v²/c² = 1/9

v²/c² = 8/9

v = c √(8/9)

v = 0.943c

Therefore, the velocity of the particle is approximately 0.943 times the speed of light, indicating that relativistic effects are indeed significant and must be taken into account.

Answer: Biological Magnification

Explanation:

Organisms acquire toxic substance from the environment along with nutrients and water. Some of the toxins are metabolized and excreted, but others accumulate in specific tissues, especially fat. One of the reasons accumulated toxins are particularly harmful is that the become more concentrated in successive trophic level of the food web, this is the process of biological magnification.

Magnification occurs because the biomass at any given level is produced from a must larger biomass ingested from the level below. Thus the top-level carnivores tend to be the organism most severely affected by toxic compounds in the environment.

Examples of toxins that demonstrate biology magnification are chlorinated hydrocarbons, and many pesticides.

Answer:

The answer to this is

The velocity of the 27.3Kg marble after collision is = 16.24 cm/s

Explanation:

To solve the question, let us list out the given variables and their values

Mass of first marble m1 = 27.3g

Velocity of the first marble v1 = 21.0 cm/s

Mass of second marble m2 = 11.7g

Velocity of the second marble v2 = 12.6 cm/s

After collision va1 = unknown and va2 = 23.7 cm/s

From Newton's second law of motion, force = rate of change of momentum produced

Hence m1v1 + m2v2 = m1va1 + m2va2 or

va1 = (m1v1 + m2v2 - m2va2)÷m2 or (720. 72-277.29)÷m1 → va1 = 16.24 cm/s

The velocity of the 27.3Kg marble after collision is = 16.24 cm/s

Answer:

The answer is a!

Explanation:

Hope this helps!

Answer:

C.overlapping p orbitals

Explanation:

The atoms which comprises of single bond is formed by sigma bond. Sigma bond is formed by the internuclear overlapping of the atomic  orbitals. They are formed due to the head on overlapping of the atomic orbitals. Since, the bond is symmetrical about the internuclear axis, it can rotate without the breakage of the bond.

On the other hand, double or triple bonds contains one or two pi bonds respectively along with one sigma bond. Pi bonds are formed by the sideways overlapping and thus they are non-symmetrical about the internuclear axis and thus it breaks if the bond is being rotated.

Thus the answer is:- C.overlapping p orbitals

Final answer:

Pi bonds are formed by the side-by-side overlap of unhybridized p orbitals on adjacent atoms, such as in the carbon atoms of an alkene. The correct answer for which orbitals form a pi bond is C: overlapping p orbitals.

Explanation:

The pi bond (π bond) typically involves the side-by-side overlap of p orbitals that are unhybridized. Notably, pi bonding can also occur with d orbitals or with p orbitals that are part of hybrid orbitals, under certain circumstances. However, in the context of this question and in typical organic structures like ethene (C₂H₄), a pi bond is the result of the sideways overlapping of p orbitals on adjacent carbon atoms. Each has one electron and is perpendicular to the line formed by the sigma bonds in the molecule.

For the given options, the correct answer is C: overlapping p orbitals, which align perpendicularly to the molecular plane formed by sigma bonds and overlap side-by-side to form a pi bond. Therefore, it is the p orbitals that must be unhybridized, as they are in the sp2 hybridization state observed in alkenes such as ethene, where each carbon atom has three sp2 hybrid orbitals in a plane and the unhybridized p orbital perpendicular to that plane leading to pi bonding.

This is because of the low pressure at the mountains.

The air pressure or atmospheric pressure is defined as the amount of pressure exerted by the air column of the atmosphere above in the atmosphere per unit area. This air pressure is inversely proportional to the height of the land above sea level. As we go up in the atmosphere, the pressure of Air decrease.

As Jackie goes in the mountains for his picnic, the pressure of air at the mountains is much lower than at her house in Austin, because Austin is at sea level. So water will boil much faster owing to low pressure. Thus, water is boiling at lower temperature. And this low temperature is easily and quickly achievable. So Austin seems that her soup is ready much faster. But the veggies and meat won't be fully cooked at that temperature. So although the soup seems to be ready, it isn't.

Answer:

Metal (appropriate charge on metal) nonmetal-ide

Explanation:

1) Write the name of transition metal as shown on the Periodic Table.

2) Write the name and charge for the non-metal.

          Use the total charge on the non-metal (or polyatomic ion) find the charge on the transition metal.

3) After the name for the metal, write its charge as a Roman Numeral in parentheses. Example: Iron (II) chloride.

Answer:

[tex]a=-1.17\times 10^{14} \hspace{3}\frac{m}{s^2}[/tex]

Explanation:

A charged particle that is in a region where there is an electric field, experiences a force equal to the product of its charge by the intensity of the electric field:

[tex]F_e=q*E[/tex]

If the electric field is uniform, the force is constant and so is the acceleration. Applying the equations of uniformly accelerated rectilinear motion, we obtain the velocity of the particle at any time or after having moved a certain distance:

[tex]a=\frac{qE}{m}[/tex] (1)

Where:

[tex]E=Electric\hspace{3}field\hspace{3}strength=664\frac{N}{C} \\q=Electric\hspace{3}charge\hspace{3}of\hspace{3}the\hspace{3}particle\\m=Mass\hspace{3}of\hspace{3}the\hspace{3}particle[/tex]

The electric charge and the mass of the electron are known constants:

[tex]q=-1.6\times 10^{-19} C\\m=9.1\times 10^{-31} kg[/tex]

So, replacing this data in the equation (1) :

[tex]a=\frac{(-1.6\times 10^{-19})*(664) }{9.1\times 10^{-31} } =-1.167472527\times 10^{14} \approx -1.17\times 10^{14} \hspace{3}\frac{m}{s^2}[/tex]

The minus sign is due to the fact that the charge is negative, therefore it experiences a force in the opposite direction to the field.

Answer: 2, 1

Explanation:

Water has a formula as H2O.

Meaning it contains 2 atoms of Hydrogen and one atom of oxygen. No matter the volume of water, it will always contain 2 atoms of Hydrogen and one atom of oxygen. The ratio of hydrogen to oxygen in a water molecule is (2, 1)

Answer:

CH2O

Explanation:

Firstly, we need to convert the masses of the elements to percentage compositions. This can be done by placing the mass of each element over the total mass multiplied by 100% . We can start with carbon.

C = 5.692/14.229 * 100 = 40%

O = 7.582/14.229 * 100 = 53.29%

H = 0.955/14.229 * 100 = 6.71%

We then proceed to divide each percentage composition by their atomic mass of 12, 16 and 1 respectively.

C = 40/12 = 3.333

O = 53.29/16 = 3.33

H = 6.71/2 = 6.71

Dividing by the smaller value which is 3.33

C = 3.33/3.33 = 1

O = 3.33/3.33= 1

H = 6.71/3.33 = 2

The empirical formula of the compound ribose is CH2O

Answer:

CH2O

Explanation:

First divide the given mass of each element by its relative atomic mass.

For carbon 5.692/12 = 0.47

For hydrogen 0.955/1 = 0.955

For oxygen 7.582/16= 0.47

Then we divide each by the lowest ratio

For carbon- 0.47/0.47 =1

For hydrogen- 0.955/0.47= 2

For oxygen- 0.47/0.47 = 1

Hence the empirical formula is CH2O

Answer:

I would answer if you had a question.