Write a balanced chemical equation, including physical state symbols, for the decomposition of solid calcium carbonate (CaCO₃) into solid calcium oxide and gaseous carbon dioxide. Suppose 23.0 L of carbon dioxide gas are produced by this reaction, at a temperature of 380.0 °C and pressure of exactly 1 atm. Calculate the mass of calcium carbonate that must have reacted. Be sure your answer has the correct number of significant digits.

Answer:

5.62 * 10^-13 moles per liter

Explanation:

The pH of a solution is the negative logarithm to base 10 of the concentration of hydrogen ions. What we simply do here is to input the information in the question into the equation:

pH=−log10[H⁺]

Here we know the pH but we do not know the concentration of the hydrogen ions.

12.25 = -log [H+]

log[H+] = -12.25

[H+] = 10^-12.25

[H+] = 5.62 * 10^-13 moles per liter

The concentration of hydrogen ions in the solution with a pH of 12.25 is calculated using the formula [H⁺] = 10^(-pH) which gives a result of 10^(-12.25) moles per liter.

The pH scale for acidity is defined by pH=-log10[H+] where [H+] is the concentration of hydrogen ions. A solution has a pH of 12.25. Given that the pH = -log10[H⁺], to get the hydrogen ion concentration when the pH value is known, you rearrange the pH formula to the following: [H⁺] = 10^-pH. Substituting 12.25 for pH, the concentration of hydrogen ions in the solution is 10^(-12.25) moles per liter. This calculation is based on the principles of logarithms and the properties of the pH scale.

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Answer:

N3- > O2- > F- > Na+ > Mg2+ > Al3+

Explanation:

The ionic radio can simply be defined as the distance from the center of the nucleus to the electron in the outermost shell.

It should be noticed that all these ions belong to elements in group 3 of the periodic table.

It must be noted that anions I.e negative ions are generally bigger than anions.

Hence, it is expected that the negative ions are bigger. The arrangement goes thus:

N3- > O2- > F- > Na+ > Mg2+ > Al3+

The ions are ranked according to the number of protons in their nucleus, from least to most, which corresponds to the decreasing ionic radii. Therefore, the order of decreasing ionic radii is: N 3-, O 2-, F -, Na+, Mg 2+, Al 3+.

The ions Na+, Mg 2+, Al 3+, O 2-, N 3- and F - all contain the same number of electrons so they are considered isoelectronic. The size of isoelectronic species depends on their nuclear charges, that is, the number of protons in their nucleus. An ion with more protons will have a stronger nuclear charge which attracts the negatively charged electrons more, causing the ion to be smaller.

So, when you put the ions in order of decreasing ionic radii, the ion with the most protons will be the smallest. Therefore, the order of decreasing ionic radii will be: N 3- < O 2- < F - < Na+ < Mg 2+ < Al 3+. This indicates that N 3- has the largest ionic radius while Al 3+ has the smallest ionic radius among these ions.

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Answer:

The molecular formula of the compounds indicates the amount of atoms that the substance contains. For example, water whose formula is H2O contains 2 atoms of hydrogen and 1 of oxygen. The representative unit of a molecular compound is a molecule while ions are represented by a formula unit.

Mole can be a unit 6.02 × 10²³. The units may be electrons, atoms, ions, or molecules, depending on the nature of the substance

Explanation:

The molecular formula of the compounds indicates the amount of atoms that the substance contains. For example, water whose formula is [tex]H2O[/tex] contains 2 atoms of hydrogen and 1 of oxygen. The representative unit of a molecular compound is a molecule while ions are represented by a formula unit.

Mole can be a unit 6.02 × 10²³. The units may be electrons, atoms, ions, or molecules, depending on the nature of the substance.

Therefore, water whose formula is [tex]H2O[/tex] contains 2 atoms of hydrogen and 1 of oxygen. The representative unit of a molecular compound is a molecule while ions are represented by a formula unit.

Learn more about water on:

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The rate law for the reaction can be determined by analyzing the effects of changing reactant concentrations. Based on the given observations, the rate law can be written as rate = k[A]/[NaSH] and rate = [tex]k[A][NaSH]^2[/tex] for the given conditions. Additionally, the rate constant, k, is temperature-dependent.

The rate law for the reaction can be determined by examining the effects of changing the concentrations of reactants on the rate of the reaction. Based on the given observations, we can conclude the following:

(a) The rate triples when the concentration of [A] is tripled and the concentration of [NaSH] is held constant. This suggests that the reaction rate is directly proportional to the concentration of A, so the rate law can be expressed as rate = k[A]

(b) The rate is decreased when the concentration of [A] is doubled and the concentration of [NaSH] is cut by a factor of 3. This implies that the rate is inversely proportional to the concentration of [NaSH], so the rate law can be written as rate = [tex]k[A]/[NaSH][/tex]

(c) The rate doubles when the concentration of [A] is cut in half and the concentration of [NaSH] is quadrupled. This indicates that the rate is quadratically proportional to the concentration of [NaSH], so the rate law can be expressed as rate = [tex]k[A][NaSH]^2[/tex]

(d) The rate increases with an increase in temperature. This suggests that the rate constant, k, in the rate law equation is temperature-dependent.

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Answer:

Hydrogen and halogens.

Explanation:

There are seven types diatomic molecules are present in natural state: Hydrogen, chlorine, fluorine, nitrogen, bromine, iodine, and oxygen.

Hydrogen is the first element which have one electron and needs only one electron to fill its valence shell and form 2 hydrogen single bond to form H2.

The halogens, chlorine, fluorine, bromine, and iodine they all contain seven valence electrons. They all need one more electron so, they are sharing their one electron to fill its valence shell, and get Cl2, F2, Br2 and I2 (all single bonds)

Oxygen contains six valence electrons, each oxygen molecule needs 2 more electrons, and they contain 2 unpaired electrons. So, they share both electrons and form double bond.

Nitrogen contains five valence electrons. Each nitrogen atom required 3 more electrons and contains 3 unpaired electrons. The 2 atoms shares all 3 with each other molecule and this form a triple bond.

So, only Hydrogen and halogens form diatomic molecules with the help of single bond

Answer:

Halogen elements and H, O, N.

Explanation:

All halogen elements can form covalent bonds with each other to form a diatomic molecule. You can also add nonmetals, H, O and N.

All halogens have a configuration that differs from that of noble gases in an electron, so these elements tend to form negative species (anions) or form simple covalent bonds.

The Halogen are Cl, F, Br, I, As.

Answer:B since it have to be in excess inorder to result into basic salt result to blue colour

Answer:

The final temperature of the given ideal diatomic gas: T₂ = 753.6 K

Explanation:

Given: Atmospheric pressure: P = 1.0 atm

Initial Volume: V₁ , Final Volume: V₂ = V₁ (1/10)

⇒ V₁ / V₂ = 10

Initial Temperature: T₁ = 300 K, Final temperature: T₂ = ? K

For a diatomic ideal gas: γ =  7/5

For an adiabatic process:

[tex]V^{\gamma-1 }T = constant[/tex]

[tex]V_{1}^{\gamma-1 }T_{1} = V_{2}^{\gamma-1 }T_{2}[/tex]

[tex]\left [\frac{V_{1}}{V_{2}} \right ]^{\gamma-1 } = \frac{T_{2}}{T_{1}}[/tex]

[tex]\left [10 \right ]^{\frac{7}{5}-1 } = \frac{T_{2}}{300 K}[/tex]

[tex]\left [10 \right ]^{\frac{2}{5} } = \frac{T_{2}}{300 K}[/tex]

[tex]2.512 = \frac{T_{2}}{300 K}[/tex]

[tex]T_{2} = 753.6 K[/tex]

Therefore, the final temperature of the given ideal diatomic gas: T₂ = 753.6 K

Answer:

neutron

Explanation:

which affects mass number

Answer:

The appropriate options are:

2. The reaction releases energy.

4. [tex][H_{2}][/tex] and [tex][I_{2}][/tex] increase.

6. [tex][HI][/tex] increases.

The addition of a non-reacting component C will have no effect on the equilibrium system at constant volume.

Explanation:

[tex]H_{2}+I_{2}\longrightarrow2HI(exothermic)[/tex]

The question can be answered by using Le Chatelier's principle.

According to Le Chatelier's Principle, for a exothermic reaction, decreasing the temperature at equilibrium will cause the forward reaction to occur.

If the forward reaction occurs, subsequently the concentrations of the reactants will decrease and that of the product will increase.

This is the reason for the options 4 and 6 being correct.

Exothermic reactions are the ones that release energy and endothermic reactions are the ones that absorb energy.

Since the forward reaction is exothermic, cooling the reaction mixture at constant volume, will lead to a release of energy.

This is the reason for the option 2 to be correct.

If a component C is added at constant volume, there will be no effect on the equilibrium system, assuming that the component C is non-reacting.

The concentration of that component C will increase, at constant volume.

Answer : The volume of water and alcohol present in 675 mL of this solution are 405 mL and 270 mL respectively.

Explanation :

As we are given that 40.0 % (v/v) alcohol solution. That means, 40.0 mL of alcohol present 100 mL of solution.

Now we have to calculable the volume of alcohol in 675 mL solution.

As, 100 mL of solution contains 40.0 mL of alcohol

So, 675 mL of solution contains [tex]\frac{675}{100}\times 40.0=270mL[/tex] of alcohol

Thus, the volume of alcohol = 270 mL

Now we have to calculate the volume of water.

Volume of water = Volume of solution - Volume of alcohol

Volume of water = 675 mL - 270 mL

Volume of water = 405 mL

Thus, the volume of water = 405 mL

Hence, the volume of water and alcohol present in 675 mL of this solution are 405 mL and 270 mL respectively.

Explanation:

Balanced equation for the reaction between benzoic acid and metanol is as follows.

  [tex]C_{6}H_{5}COOH + CH_{3}OH \overset{H_{2}SO_{4}}{\rightarrow} C_{6}H_{5}COOCH_{3}[/tex]

Since, volume of [tex]H_{2}SO_{4}[/tex] is very small so, that is catalytic amount of [tex]H_{2}SO_{4}[/tex] which is used.

As mass of benzoic acid is 100 mg. Hence, moles of benzoic acid are calculated as follows.

      No. of moles of benzoic acid = [tex]\frac{mass}{molar mass}[/tex]

                                                       = [tex]\frac{100 mg}{122.12 g/mol}[/tex]

                                                       = 0.818 mmol

And, mass of methanol = volume × density

                                       = [tex]10 ml \times 0.792 g/mol[/tex]

                                       = 7.92 g

Now, number of moles of methanol is as follows.

     No. of moles of methanol = [tex]\frac{mass}{molar mass}[/tex]

                                                       = [tex]\frac{ 7.92 g}{32.04 g/mol}[/tex]

                                                       = 0.024 mol      

                                                       = 24.7 mmol    

As number of moles of benzoic acid are smaller than the number of moles of methanol. Hence, benzoic acid is the limiting reagent.

As per the balanced equation, 1 mole of benzoic acid produces 1 mole of methyl benzoate.

Hence, 0.818 mmol of benzoic acid would produce 0.818 mmol of methyl benzoate. Therefore, theoretical yield of methyl benzoate is as follows.

     Theoretical yield of methyl benzoate = [tex]0.818 mmol \times 136.15 g/mol[/tex]      

                                             = 111.48 mg

or,                                          = 111.5 mg (approx)

Now, we will calculate the percent yield of the reaction as follows.

            Percent yield = [tex]\frac{\text{Actual yield}}{\text{Theoretical yield}} \times 100[/tex]

                                   = [tex]\frac{75 mg}{111.5 mg} \times 100[/tex]

                                   = 67.27%

Therefore, we can conclude that the actual yield of the reaction is 67.27%.

Final answer:

The limiting reagent in the synthesis of methyl benzoate from benzoic acid and methanol is benzoic acid. The theoretical yield is approximately 111.5 mg of methyl benzoate, and with an actual yield of 75 mg, the percent yield is approximately 67.26%.

Explanation:

The balanced chemical equation for the reaction between benzoic acid (C7H6O2) and methanol (CH3OH) to produce methyl benzoate (C8H8O2) and water (H2O) in the presence of sulfuric acid (H2SO4) as a catalyst is:

C7H6O2 + CH3OH
ightarrow C8H8O2 + H2O

To determine the limiting reagent, we need to compare the mole ratios of the reactants. The molar mass of benzoic acid is about 122.12 g/mol and methanol is about 32.04 g/mol. Converting the mass of benzoic acid (100 mg = 0.1 g) to moles yields 0.000819 moles, while 10 mL of methanol (assuming a density of approximately 0.79 g/mL) gives 0.248 moles. Since benzoic acid has fewer moles, it is the limiting reagent.

The theoretical yield of methyl benzoate can be calculated based on the moles of benzoic acid, which will also be equal to the moles of water produced as this is a 1 to 1 reaction. This yields 0.000819 moles of methyl benzoate, and with a molar mass of 136.15 g/mol, the theoretical mass of methyl benzoate is approximately 111.5 mg.

The actual yield is 75 mg of methyl benzoate. Therefore, the percent yield can be calculated by dividing the actual yield by the theoretical yield and multiplying by 100, which results in approximately 67.26%.

Answer:

a) binary compounds with iodine should all be polar covalent with a δ- on I.

Explanation:

Electronegativity can be defined as the ability of an atom to attract shared pair of electrons towards itself.

the correct answer is a) binary compounds with iodine should all polar covalent with a δ- on I.

The binary compounds as the name suggests are compounds made of two elements. Halogens being the most electronegative element in periodic table  , tend to attract the shared pair towards themselves. Iodine has high electronegativity and large atomic size hence it polarizes the electron cloud towards itself. Due to this it acquires a negative charge on it. therefore, bonds are polar with δ- charge on iodine.

Final answer:

Compounds with iodine may be ionic, polar covalent, or nonpolar covalent depending on the other element it is bonded with.

Explanation:

Based on the general guidelines for electronegativities and bond character, compounds with iodine may be ionic, polar covalent, or nonpolar covalent. The electronegativity of iodine is 2.5, which falls within the range where both ionic and polar covalent bonds can form. Therefore, binary compounds with iodine can exhibit a range of bond character depending on the other element it is bonded with.

Answer:

The answer to your questions is below

Explanation:

1.- Gas  matter with no definite shape or volume

2.- Liquid matter with no definite shape but with definite volume

3.- Sublimation the process of a solid changing directly to a gas without forming a liquid.

4.- Plasma matter in a high-energy state in which electrons are separated from their nuclei

5.- Solid matter with definite shape and volume

6.- Intermolecular bonds weak electrostatic bonds that form between particles of a substance

Final answer:

The matchings are 1-a, 2-c, 3-f, 4-d, 5-e, and 6-b, identifying the physical state or process corresponding to each description given in Part A using basic knowledge of the properties of the different states of matter.

Explanation:

To match the given descriptions in Part A with the correct terms in Part B, we need to understand the basic properties of the different states of matter and recognize the processes they undergo:

Gas: Matter with no definite shape or volume.

Ionic compounds are formed when a metal and a nonmetal react, leading to a transfer of electrons and the formation of ions. These ions are held together by ionic bonds, which demonstrate strong electrostatic attraction. These compounds display unique properties, including high melting and boiling points, and they can conduct electricity when dissolved or melted.

An ionic compound is formed when an element composed of atoms that readily lose electrons (a metal) reacts with an element composed of atoms that readily gain electrons (a nonmetal). This process usually leads to a transfer of electrons, resulting in the production of ions. For example, sodium atoms can lose an electron to form positively charged sodium ions (Na+), while chlorine atoms can gain an electron to form negatively charged chloride ions (Cl-). A compound such as NaCl consists of these sodium and chloride ions held together by ionic bonds — the electrostatic attractions between oppositely charged ions.

Ionic compounds have certain distinct properties. They exhibit a crystalline structure and are usually rigid and brittle. Their melting and boiling points tend to be high, implying the strength of the ionic bonds. These compounds are poor conductors of electricity in their solid state due to the immobility of ions, but once dissolved or melted, they become excellent conductors because the ions are free to move.

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None of the options are not used in this experiment, hence "all of the above" is the correct answer.

Option: E

Explanation:

In the above experiment "back titration" is opted because of the need to determine "strength of an analyte" as "molar concentration" of an excess reactant is known. It is done when acid or mostly base is an insoluble salt, when reaction take palce very slowly and definitely when endpoint would be hard to discern for example titration of weak acid and weak base. The procedure to follow back titration is firstly the volatile analyte is reacted with an excess reagent then the titration is done on remaining amount of known solution.

Answer:

a.

Explanation:

By the Linus Pauling's diagram, we know that the order of the energy of the subshell at the same atom, from the less to the higher, is:

1s < 2s < 2p < 3s < 3p < 4s < 4d ...

As larger is the atom, the attraction energy between the electron and the nuclei is weak. The size of the atom increase from right to left in the periods, and from the top to the bottom in the families. The cations are smaller than the neutral atoms (the attraction is more effective with fewer electrons), and the anions are larger than the neutral atoms. So, in order of size, and also the energy of the similar subshells:

He⁺ < He < H

How higher the energy, less negative it is, so less stable is the orbital.

a. As shown above, the energy of the orbital at H is higher than the energy at the orbital at He⁺, so the 1s orbital is more stable at He⁺, and the sentence is incorrect.

b. As shown above, the energy of the orbital at He is higher than the energy of the orbital He⁺, so the 2s orbital at He is less stable than the 2s orbital at He⁺, and the sentence is correct.

c. From the Linus Pauling's diagram, the energy of 2p is higher than the energy of the 2s, so the 2s subshell is more stable, and the sentence is correct.

Answer:

35.4575 amu

Explanation:

We use the relative abundance of each of the isotopes.

Let the isotopes be A and B.

Since A is having an abundance of 75.53, the abundance of B would be 100 - 75.53 = 24.47%

The average atomic mass is calculated as follows;

(75.53/100 * 34.96885)  + (24.47/100 * 36.96590) = 26.4119 + 9.0456 = 35.4575 amu

Final answer:

To find the average atomic mass of an element with two isotopes, multiply each isotope's mass by its fractional abundance and sum the results. The average atomic mass for the element given with isotopic masses of 34.96885 amu and 36.96590 amu is 35.4458 amu, which identifies the element as chlorine.

Explanation:

The average atomic mass of an element that is a mixture of two isotopes can be calculated using the isotopic masses and their abundances. In this case, we have two isotopes with masses of 34.96885 amu and 36.96590 amu and an abundance of 75.53% and 24.47% (100% - 75.53%), respectively. To find the average atomic mass, we multiply each isotope's mass by its abundance (as a decimal), and then add the results.

First, for the isotope with a mass of 34.96885 amu and an abundance of 75.53%, we calculate:

34.96885 amu × 0.7553 = 26.4062 amu

Similarly, for the other isotope with a mass of 36.96590 amu, we use its abundance of 24.47% (100% - 75.53%):

36.96590 amu × 0.2447 = 9.0396 amu

Adding these together gives us the average atomic mass:

26.4062 amu + 9.0396 amu = 35.4458 amu

The average atomic mass is 35.4458 amu. Comparing this with the periodic table, we can identify the element as chlorine since its atomic mass is closest to this calculated average.

Answer:

Cu(s) in Cu(NO₃)₂(aq)

Explanation:

The standard reduction potential (E°) is the energy necessary to reduce the atom in a redox reaction. When an atom reduces it gains electrons from other than oxides. As higher is E°, easily it will reduce. The substance that reduces is at the cathode of a cell, where the electrons go to, and the other that oxides are at the anode of the cell.

The standard reduction potentials from Al(s) and Cu(s) are, respectively, -1.66V and +0.15V, so the half-cell of Cu(s) in Cu(NO₃)₂(aq) is the cathode.

Answer:

The percentage yield is 90.9 % (option e)

Explanation:

A simple rule of three to explain this.

If the theoretical yield of the reaction is 47.2 g Fe, we assume it as 100%, then what percentage of yield means 42.9 g Fe

47.2 g Fe _____ 100 %

42.9 g Fe ______ ( 42.9  .  100)/ 47.2 = 90.88%

Substituting the given values, the percentage yield is approximately E) 90.9%.

To find the percentage yield, we need to use the formula:

Percentage Yield = (Actual Yield / Theoretical Yield) × 100%

Given the actual yield as 42.9 g Fe and the theoretical yield as 47.2 g Fe, we can substitute these values into the formula:

Calculating -

[tex]\text{Percentage Yield} &= \left( \frac{\text{Actual Yield}}{\text{Theoretical Yield}} \right) \times 100\% \\\\\text{Percentage Yield} &= \left( \frac{42.9 \, \text{g}}{47.2 \, \text{g}} \right) \times 100\% \\\\\text{Percentage Yield} &= \left( \frac{42.9}{47.2} \right) \times 100\% \\\\\text{Percentage Yield} &\approx 0.9091 \times 100\% \\\\\text{Percentage Yield} &\approx 90.91\%[/tex]

Therefore, the percentage yield of the reaction is E) 90.9%.

Answer:

D is the correct option.

Explanation:

The carbon atoms are bonded together by a double bond.

The carbon atoms are bonded together by single bonds.

Lets analyse each option:

A) Its false. Lets look at the obvious: Ethylene is a gas and polyethylene is a solid. Monomers and polymers have very different properties.

B) Its false. Polyethylene doesnt have double bonds.

C) False as well. Polyethylene doesnt have double bonds.

D) True. It is evident from the structure of the the monomer and polymer that I've shown above. I'll also provide neat structures in the attachments.

Answer:

Liquid to gas

Explanation:

There are three states of matter, the solid, liquid and gaseous states. These states can be compared in a number of ways. These comparisms would tell us that the molecules of gases have the highest mobility.

The freedom possessed by these molecules are as a result of there inherent kinetic energy. While we have the highest confinement for solids, molecules of solids still have a level of freedom and hence although confined can move in some directions but are not entirely free from the total confinement of intermolecular forces like solids.

Hence,this total freedom is a character of gaseous molecules. As we were made to know in the question that they already had exhibited degree of movement to an extent,the total breakaway is to the gaseous state.

Thus,the phase transition is from liquid to gaseous state.

Vaporization (evaporation) is the transition from liquid to gas as atoms gain energy, break free of surface attractions, and move freely.

Vaporization (evaporation) is the change of state taking place when atoms at the surface of a substance absorb energy, overcome attractions to nearby atoms, and break free of the surface, transitioning from liquid to gas. This process involves the absorption of energy, which allows particles to move freely and transition into the gas phase.

Answer:

Option D is correct.

Explanation:

Option D is correct.

Solar cells are replacing the conventional ways of making electricity. They are getting cheaper with each coming day. Secondly they use the renewable energy which causes no pollution and is available in large amount as our sun is a continuous source of energy. Another reason fossil fuels are getting out of fashion because they require huge setups and initial cost. Their burning emit green house and other toxic gases which cause rise in temperature and pollution. Also their amount is decreasing which make it expensive to use.

Answer:

The solution in the buret, during a titration is called titrant.

Explanation:

A titration is a useful process, that makes you know the concentration of a solution.  A titrant solution (burette) is evaluated against a titrand to control the pH changes against the volume aggregate. Only a strong acid with a strong base, a strong base with a strong acid, a weak acid with a strong base and a weak base with strong acid are valued.

When the pH reaches the equivalence point, it is said that the normality of the acid by the milliequivalents, is equal to the basic normality by its milliequivalents. In conclusion, the entire base / acid became its conjugate pair.

To check this sudden change in pH, a substance is used, called Indicator that changes the color of the titrand (analyte).

In a titration analysis, the substance in the buret is called the 'titrant'. It is used to react with the analyte, the sample solution whose concentration we're measuring. The goal is to reach the endpoint, the point when a distinct visual change indicates that the titrant has completely reacted with the analyte.

In a titration analysis, the solution in the buret is called the titrant. This solution contains a known concentration of a substance. During a titration, this titrant is added incrementally to a sample solution, called the analyte, which contains the substance whose concentration is to be measured. The titrant and analyte undergo a chemical reaction of known stoichiometry.

By measuring the volume of the titrant solution needed to completely react with the analyte, scientists can calculate the concentration of the analyte. This point where the titrant has completely reacted with the analyte is termed the equivalence point of the titration. The process of adding the titrant is halted when a distinct change is visually detected in the solution - this could be a color change, for example. This is known as the end point.

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Answer:

The metal with a volume of [tex]1.38 cm^3 [/tex] is zinc.

Explanation:

Density is defined as mass of the substance present in the unit volume of the substance.

[tex]Density=\frac{mass}{Volume}[/tex]

For aluminum:

Mass of aluminium metal , M = 4.60 g

Volume of the aluminium metal = V

Density of the aluminium metal = d = [tex]2.70 g/cm^3[/tex]

[tex]V=\frac{M}{d}=\frac{4.60 g}{2.70 g/cm^3}=1.70 cm^3[/tex]

For Zinc :

Mass of zinc metal , M = 9.81 g

Volume of the zinc metal = V

Density of the zinc metal = d = [tex]7.13 g/cm^3[/tex]

[tex]V=\frac{M}{d}=\frac{9.81 g}{7.13 g/cm^3}=1.38 cm^3[/tex]

For chromium :

Mass of chromium metal , M= 6.24 g

Volume of the chromium metal = V

Density of the chromium metal = d = [tex]7.18 g/cm^3[/tex]

[tex]V=\frac{M}{d}=\frac{6.24 g}{7.18 g/cm^3}=0.87 cm^3[/tex]

For nickel :

Mass of nickel metal , M= 3.17 g

Volume of the nickel metal = V

Density of the nickel  metal = d = [tex]8.90 g/cm^3[/tex]

[tex]V=\frac{M}{d}=\frac{3.17 g}{8.90 g/cm^3}=0.36 cm^3[/tex]

The metal with a volume of [tex]1.38 cm^3 [/tex] is zinc.

Answer:

B - zinc

Explanation:

Hope this helps! ✌

Answer:

There are needed 237.15 g of sucrose.

Explanation:

The 31.0 % (w/v) of the sucrose solution means that in 100 ml of solution, you have 31 g of solute, in this case sucrose.

So you want to make a solution with 765 mL.

Let's think the rule of three:

100 mL solution__contain __31 g sucrose

765 mL solution _________ (765 . 31 ) /100 = 237.15 g

Answer:

[tex]Al(OH)_{3}(s)+3H^{+}(aq.)+3Br^{-}(aq.)\rightarrow Al^{3+}(aq.)+3Br^{-}(aq.)+3H_{2}O(l)[/tex]

[tex]Al(OH)_{3}(s)+3H^{+}(aq.)\rightarrow Al^{3+}(aq.)+3H_{2}O(l)[/tex]

Explanation:

Aluminium hydroxide ([tex]Al(OH)_{3}[/tex]) is a base and hydrobromic acid (HBr) is a strong acid.

Hence an acid-base reaction occurs between [tex]Al(OH)_{3}[/tex] and HBr

Balanced molecular equation:

[tex]Al(OH)_{3}(s)+3HBr(aq.)\rightarrow AlBr_{3}(aq.)+3H_{2}O(l)[/tex]

Balanced total ionic equation:

[tex]Al(OH)_{3}(s)+3H^{+}(aq.)+3Br^{-}(aq.)\rightarrow Al^{3+}(aq.)+3Br^{-}(aq.)+3H_{2}O(l)[/tex]

Balanced net ionic equation:

[tex]Al(OH)_{3}(s)+3H^{+}(aq.)\rightarrow Al^{3+}(aq.)+3H_{2}O(l)[/tex]

(net ionic equation is written by removing common ions present in both side of total ionic equation)

i would saythat the answer would be D

Answer : The molecular formula of a caffeine is, [tex]C_8H_{10}N_4O_2[/tex]

Solution :

If percentage are given then we are taking total mass is 100 grams.

So, the mass of each element is equal to the percentage given.

Mass of C = 49.48 g

Mass of H = 5.19 g

Mass of N = 28.85 g

Mass of O = 16.48 g

Molar mass of C = 12 g/mole

Molar mass of H = 1 g/mole

Molar mass of N = 14 g/mole

Molar mass of O = 16 g/mole

Step 1 : convert given masses into moles.

Moles of C = [tex]\frac{\text{ given mass of C}}{\text{ molar mass of C}}= \frac{49.48g}{12g/mole}=4.12moles[/tex]

Moles of H = [tex]\frac{\text{ given mass of H}}{\text{ molar mass of H}}= \frac{5.19g}{1g/mole}=5.19moles[/tex]

Moles of N = [tex]\frac{\text{ given mass of N}}{\text{ molar mass of N}}= \frac{28.85g}{14g/mole}=2.06moles[/tex]

Moles of O = [tex]\frac{\text{ given mass of O}}{\text{ molar mass of O}}= \frac{16.48g}{16g/mole}=1.03moles[/tex]

Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.

For C = [tex]\frac{4.12}{1.03}=4[/tex]

For H = [tex]\frac{5.19}{1.03}=5.03\approx 5[/tex]

For N = [tex]\frac{2.06}{1.03}=2[/tex]

For O = [tex]\frac{1.03}{1.03}=1[/tex]

The ratio of C : H : N : O = 4 : 5 : 2 : 1

The mole ratio of the element is represented by subscripts in empirical formula.

The Empirical formula = [tex]C_4H_5N_2O_1=C_4H_5N_2O[/tex]

The empirical formula weight = 4(12) + 5(1) + 2(14) + 16 = 97 gram/eq

Now we have to calculate the molecular formula of the compound.

Formula used :

[tex]n=\frac{\text{Molecular formula}}{\text{Empirical formula weight}}[/tex]

[tex]n=\frac{194.19}{97}=2[/tex]

Molecular formula = [tex](C_4H_5N_2O)_n=(C_4H_5N_2O)_2=C_8H_{10}N_4O_2[/tex]

Therefore, the molecular of the caffeine is, [tex]C_8H_{10}N_4O_2[/tex]

Explanation:

No, an exothermic reaction will not be  favored or less favored if it were carried out within a super heated chamber. In the super heated chamber the heat will flow back to the reaction( considering heat emitted by the reaction is less than the heat in a super heated chamber). So, the reaction will shift backward instead, the product will again change into reactant.