Calculate the temperature and state the appropriate phase(s) (solid, liquid, vapor) for each substance: This temperature is: Fahrenheit A. SubstanceMelting Point (K)Boiling Point (K)Phase(s) Oxygen, O254.7590.19 Methane, CH493.15109.10 Water, H2O273.15373.15

Answer:

Protons, Neutrons, and Electrons are all in atoms so the one not present would be the Element since Elements are made of atoms.

Explanation:

[tex]\text{GaBr}_3[/tex]

Answer:

C. As scientists have learned more about chemicals, they have  become more aware of their dangers

Explanation:

Chemicals are substances with standard compositions, held together by chemical bonds. Chemicals can exist in different phases such as solid, liquid, and gaseous phases. Over time, with a growing understanding of chemicals, their composition, and their reaction methods, scientists now have a better knowledge of the dangers chemicals can pose. To that effect, they have created standard safety measures for those who have to work with these chemicals.

When these guidelines are strictly adhered to, the chances of suffering accidents, burns, and explosions with these chemicals are significantly reduced.

Answer:

2.7255 kg Fe

Explanation:

Based on the reaction of the thermite process:

2 Al(s) + Fe₂O₃(s) → Al₂O₃(s) + 2 Fe(l)

2.88kg of Al (Molar mass: 26.98g/mol) are:

2880g ₓ (1mol / 26.98g) = 106.7 moles Al

For a complete reaction of these moles of Al are necessaries:

106.7 moles Al ₓ ( 1 mol Fe₂O₃ / 2 moles Al) = 53.35 moles Fe₂O₃

As you have just 24.4 moles of Fe₂O₃, Fe₂O₃ is limiting reactant.

1 mole of Fe₂O₃ produce 2 moles of Fe.

Thus, moles of Fe produced are 24.4×2 = 48.8 moles of Fe.

As molar mass of Fe is 55.85g/mol, mass of Fe is:

48.8 moles Fe ×(55.85g / mol) = 2725.5g of Fe =

Answer:

Consider each of the following molecules in turn: (a) dimethyl ether, (CH3)2O; (b) trimethylamine, (CH3)3N; (c) trimethylboron, (CH3)3B; and (d) carbon dioxide (CO2). Describe the hybridization state of the central atom (i.e., O, N, B, or C) of each molecule, tell what bond angles you would expect at the central atom, and state whether the molecule would have a dipole moment.

Answer: Zn (s) |Zn2+ || Au1+| Au(s)

Explanation:

Answer:

(a) [tex]Ca(NO_3)_2(s)\rightarrow Ca^{2+}(aq)+2NO_3^-(aq)[/tex]

(b) [tex]Na_3PO_4(s)\rightarrow 3Na^++PO_4^{3-}[/tex]

(c) [tex]Ca^{2+} \ and \ PO_4^{3-}[/tex]

(d) [tex]3Ca^{2+}(aq)+2PO_4^{3-}(aq)\rightarrow Ca_3(PO_4)_2(s)[/tex]

Explanation:

Hello,

In this case, the balanced dissolution reactions are:

(a) [tex]Ca(NO_3)_2(s)\rightarrow Ca^{2+}(aq)+2NO_3^-(aq)[/tex]

(b) [tex]Na_3PO_4(s)\rightarrow 3Na^++PO_4^{3-}[/tex]

Moreover, when calcium nitrate and sodium phosphate react a double displacement reaction occurs, forming calcium phosphate, which is actually the precipitate due to its low solubility in water, and sodium nitrate:

[tex]2Na_3PO_4(aq)+3Ca(NO_3)_2(aq)\rightarrow 6NaNO_3(aq)+Ca_3(PO_4)_2(s)[/tex]

Thus, the precipitate is formed by:

(c) [tex]Ca^{2+} \ and \ PO_4^{3-}[/tex]

Finally, the net precipitation reaction shows the involved cation, anion and final product:

(d) [tex]3Ca^{2+}(aq)+2PO_4^{3-}(aq)\rightarrow Ca_3(PO_4)_2(s)[/tex]

Regards.

Answer:

a) Fe(s) + Ni^2+(aq) ----> Fe^2+(aq) + Ni(s)

b) no reaction

c) no reaction

d) 2Mg(s) + 2H2O(l)-----> 2Mg^2+(aq) + O2(g) +4H^+(aq)

e) no reaction

Explanation:

It is important to say here that the ability of a particular chemical specie to displace another chemical specie is dependent on the relative standard reduction potentials of the species involved.

All the reactions stated above are redox reactions. Let us take reaction E as an example. Mg^2+ has a reduction potential of -2.37 V while Cr^3+ has a reduction potential of -0.74V. Since the reduction potential of magnesium is more negative than that of chromium, there is no reaction when a piece of chromium metal is dipped into a solution of Mg^2+.

Similarly, though metals displace hydrogen gas from dilute acids, metals that are less than hydrogen in the reactivity series cannot do that. This explains why there is no reaction when copper and silver are dipped into dilute acid solutions.

Reaction occurs when iron is dipped into a nickel solution because the reduction potential of Fe^2+ is far more negative than that of Ni^2+.

Answer:

melting point will be higher than that of pure ethyl acetate

Explanation:

Answer:

20mL of the stock solution and dilute to 100mL

Explanation:

20mM = 0.020M is the concentration of the diluted solution. As you want to prepare this solution from a 0.1M solution, dilution factor is:

0.1M / 0.020M = 5

That means you need to dilute the stock solution 5 times to obtain the 20mM sucrose solution.

As you want to prepare 100mL, you need to add:

100mL / 5 =

Answer and Explanation:

The computation of the energy or wavelength gamma rays observed is shown below:

Since the energy of gamma rays is higher than 0.10 MeV.

Now We have to calculate transitions in between the given levels of energy that correspond to this energy.

As per the given question, we have the following information

Ground state = E where E < 0.075 MeV

For  Level 1 = 0.075 MeV

For Level 2 = 0.320 MeV

For Level 3 = 0.475 MeV

Now we have to take the below transitions:

1. [tex]3 \rightarrow 2[/tex]

Difference of energy is

= 0.475 - 0.320

= 0.155 MeV

This represents  a gamma radiation

2. [tex]3 \rightarrow 1[/tex]

Difference of energy is

= 0.475 - 0.075

= 0.4 MeV

This represents  a gamma radiation

3. [tex]3 \rightarrow ground[/tex]

Difference of energy is

= 0.475 - E > 0.155 MeV

This represents  a gamma radiation

4. [tex]2 \rightarrow 1[/tex]

Difference of energy is

= 0.320 - 0.075

= 0.245 MeV

This represents  a gamma radiation

5. [tex]2 \rightarrow ground[/tex]

Difference of energy is

= 0.320 - E > 0.245 MeV

This represents  a gamma radiation

6. [tex]1 \rightarrow Ground[/tex]

Difference of energy is

= 0.075 - E < 0.10 MeV

This represents not a gamma radiation

We can see that there are 5 transitions that contain gamma rays

Answer: D. Chemical potential energy being converted to kinetic energy

Explanation: Batteries are chemical and that energy is converted into kinetic to make the hands on the clock move :) hope this helped!

Answer:

Explanation:

Stereoisomers are two or more atoms that  have the same bonding order of atoms but there is a difference  spatial arrangement of  the  atoms in space.

A plane of symmetry divides a molecule into two equal halves.

A chiral stereoisomer are not superimposed on a mirror image , Hence they do not posses a plane of symmetry.

As a result to that. these non-superimposable mirror images are said to be Enantiomers.

However, a Fischer Projection emanates from a two - dimensional figure which is used for presenting a three - dimensional organic molecules.

From the given question;

Fischer projection for an enantiomer of 2-bromo-2,3-dihydroxypropanal with the bromine oriented horizontally to the left and the hydroxide group oriented horizontally to the right.

we can sketch the way the enantiomer of 2-bromo-2,3-dihydroxypropanal can  be seen like the one shown below:

              CH₂OH

                   |

                   |

                   |

Br -------------|----------------OH

                   |

                   |

                   |

                 CHO

The objective of this question is to drawn the perspective formula of the molecule.

So , from the attached file below; we can see the perspective formula of the molecule in a well structured 3-D format.

Answer:

C ) The rate will triple

Answer:

1.) Option C is correct.

The rate of reverse reaction is greater than zero, but equal to the rate of the forward reaction.

2) Option B is correct.

The rate of reverse reaction is Greater than zero, but less than the rate of the forward reaction.

3) Option C is correct.

The rate of reverse reaction is Greater than zero, and equal to the rate of the forward reaction.

4) Option A is correct.

How much less C2H5CO2CH3 is in the flask when the system has again reached equilibrium? Zero.

Explanation:

HCH,CO2(aq) + C2H5OH(aq) ⇌ C2H,CO2CH3(aq) + H2O

1) Before the main product is removed from the reaction setup, the chemical reaction is at equilibrium.

Chemical equilibrium is a state of dynamic equilibrium such that the concentration of the reactants and the products do not always remain the same but the rate of forward reaction always matches the rate of backward reaction.

2) When 246. mmol of C2HCO2CH3 are removed from the reaction mixture....

And when one of the factors involved in chemical equilibrium changes, Le Chatellier's principle explains that the system then adjusts to remedy this change and takes time to go back to equilibrium again.

When one of the species involved in the chemical reaction at equilibrium, is removed from the reaction mixture, the rate of reaction begins to favour that side of the reaction until equilibrium is re-established.

So, when 246 mmol of one of the products is removed, the response is to cause the rate of forward reaction to be favoured to produce more of products as there are fewer, and the rate of reverse reaction at this moment becomes less than the rate of forward reaction.

3) The rate of the reverse reaction when the system has again reached equilibrium

Like I said in (2) above, the reaction remedies this change in concentration of one of the products until equilibrium is re-established and when chemical equilibrium is re-established the rate of forward reaction once again matches the rate of backward reaction.

4) How much less C2H5CO2CH3 is in the flask when the system has again reached equilibrium?

By the time equilibrium is re-established, the system goes back to how it all was and the concentration of C2H5CO2CH3 goes back to the same as it was at the start of the reaction.

Hope this Helps!!!

Answer:

Explanation:

Hello,

We'll be doing some classification of some chemical substances based on molecules, elemental state or ionic or electrovalent properties.

A) Ag = atomic element : silver (Ag) in its elemental state is an atomic element.

B) Cd = atomic element : Cadmium (Cd) is an element of the periodic table and belongs to transition metal.

C) MgCl = ionic compounds: this is a compound formed between magnesium (Mg) and chlorine (Cl) to give MgCl. This compound has ionic or electrovalent properties since electron transfer occurred between the cation (Mg) and anion (Cl).

D) F₂ = moleculer element : Fluorine F₂ is moleculer element since two elements of fluorine combine together to form a molecule.

E) HI = molecular compound : this is a compound formed from the reaction between hydrogen and iodine. It's a molecular compound because they are two different elements combining together to form a compound.

F) NO₂ = molecular compound

G) NaCl = ionic compound

H) Cl₂ = molecular element

Answer:

3- gamma radiation

Explanation:

Hello,

In the above question, 4 of the options are related to polymerization which are

1. Synthetic polymer

2. Natural polymer

3. Condensation polymerization

4. Addition polymerization.

The first two options are types of polymer that exists while the last two are polymerization techniques.

The odd option here which is "gamma radiation" is a particle which is emitted from radioactive substances during decay. It has no mass and no charge but it is highly penetrating and dangerous to human health.

However,

Synthetic polymers are also known as man made polymers and they exist around us because they're present in materials which we use everyday. An example is polyethylene, nylon-6,6 etc

Natural polymers are compounds which are polymeric in nature (compounds catenating to form a complex molecule). Natrual occurring polymers can be found in proteins and some lipids.

Answer:

0°C.

Explanation:

Hello,

In this case, given the heating curve of water on the attached document, we can notice that at 0 °C the solid starts melting, which means that the melting point is reached. Melting point is known as a physical change whereby a solid changes to liquid by the addition of heat as it allows the molecules to separate to each other.

Best regards.

Answer:

0 degrees celcius

Explanation:

I took the test

Answer:

[tex]Kb=6.16x10^{-7}[/tex]

Explanation:

Hello,

In this case, given the pH of the base, we can compute the pOH as shown below:

[tex]pOH=14-pH=14-10.781=3.219[/tex]

Next, we compute the concentration of the hydroxyl ions when the triethanolamine is dissociated:

[tex]pOH=-log([OH^-])[/tex]

[tex][OH^-]=10^{-pOH}=10^{-3.219}=6.04x10^{-4}M[/tex]

Then, by writing the equilibrium expression for the dissociation of triethanolamine we have:

[tex]Kb=\frac{[OH^-][C6H14O2N^+]}{[C6H15O3N ]}[/tex]

That is suitable for the direct computation of Kb, knowing that based on the ICE procedure, [tex]x[/tex] equals the concentration of hydroxyl ions that was previously, computed, therefore, we have:

[tex]Kb=\frac{6.04x10^{-4}M*6.04x10^{-4}M}{0.592M-6.04x10^{-4}M}\\ \\Kb=6.16x10^{-7}[/tex]

Regards.

Answer:

n=2 to n=4 < n=6 to n=8 < n=10 to n=12 < n=14 to n=16

Explanation:

According to Neils Bohr, electrons in an atom are found in specified energy levels. Transitions are possible from one energy level to another when the electron receives sufficient energy usually in the form of a photon of electromagnetic radiation of appropriate frequency and wavelength. The energy of this photon corresponds to the energy difference between the two energy levels. Thus the higher the energy difference between energy levels, the greater the energy of the photon required to cause the transition and the shorter the wavelength of the photon.

High energy photons have a very short wavelength. It should be noted that as n increases, the energy of successive energy levels decreases and transitions between them now occurs at longer wavelengths. Hence, the highest energy and shortest wavelength of photons are required for transition involving lower values of n because such electrons are closer to the nucleus and are more tightly bound to it than electrons found at a greater distance from the nucleus.

Hence transition involving electrons at higher energy levels occur at a longer wavelength compared to transition involving electrons closer to the nucleus. This is the basis for the arrangement of wavelengths required to effect the various electronic transitions shown in the answer.

Answer: Reaction 1 is non spontaneous.

Explanation:

According to Gibb's equation:

[tex]\Delta G=\Delta H-T\Delta S[/tex]

[tex]\Delta G[/tex] = Gibbs free energy  

[tex]\Delta H[/tex] = enthalpy change

[tex]\Delta S[/tex] = entropy change  

T = temperature in Kelvin

When [tex]\Delta G[/tex] = +ve, reaction is non spontaneous

[tex]\Delta G[/tex]= -ve, reaction is spontaneous

[tex]\Delta G[/tex]= 0, reaction is in equilibrium

For the given reaction 1: [tex]glucose+Pi\rightarrow glucose-6-phosphate+H_2O[/tex] [tex]\Delta G=+13.8kJ/mol[/tex]

As for the reaction 1 , the value of Gibbs free energy is positive and thus the reaction 1 is non spontaneous.

Boric acid is not what is known as a protonic acid meaning it is unable to release the H+ ions by itself. However, it can act as a traditional Lewis Acid so it is considered a weak acid.

Answer:

Boric acid is not able to release H⊕ ion on its own. It receives ӨOH ion from water molecule to complete its octet and in turn releases H⊕ ions.

It has the chemical formula H3BO3 (sometimes written B(OH)3), and exists in the form of colorless crystals or a white powder that dissolves in water. When occurring as a mineral, it is called sassolite

credit : wikipedia

Answer:

product won't form hydrogen bond with water

Explanation:

Answer:

See detailed answer with explanation below.

Explanation:

Valence electrons are electrons found on the outermost shell of an atom. They are the electrons in an atom that participate in chemical combination. Recall that the outermost shell of an atom is also referred to as its valence shell. Let us consider an example; if we look at the atom, sodium-11, its electronic configuration is 2,8,1. The last one electron is the valence electron of sodium which is found in its outermost or valence shell.

Positive ions are formed when electrons are lost from the valence shell of an atom. For instance, if the outermost electron in sodium is lost, we now form the sodium ion Na^+ which is a positive ion. Positive ions possess less number of electrons compared to their corresponding atoms.

Negative ions are formed when one or more electrons is added to the valence shell of an atom. A negative ion possesses more electrons than its corresponding atom. For example, chlorine(Cl) contains 17 electrons but the chloride ion (Cl^-) contains 18 electrons.

In molecular compounds, a bond is formed when two electrons are shared between the bonding atoms. Each bonding atom may contribute one of the shared electrons (ordinary covalent bond) or one of the bonding atoms may provide the both shared electrons (coordinate covalent bond). The shared pair may be located at an equidistant position to the nucleus of both atoms. Similarly, the electron may be drawn closer to the nucleus of one atom than the other (polar covalent bond) depending on the electro negativity of the two bonding atoms.

The electrons are shared in order to complete the octet of each atom by so doing, the both bonding atoms now obey the octet rule. For example, two chlorine atoms may come together to form a covalent bond in which each chlorine atom has an octet of electrons on its outermost shell.

Answer:

A) Decreasing solubility with increasing lattice energy.

B) Ionic compounds are more soluble in a polar solvent.

C) Increasing solubility with increasing enthalpy of hydration.

Explanation:

A) Lattice energy is the energy contained in the crystal lattice of a compound (mostly ionic). It is also the energy that would be released if the component ions were brought together from infinity to form the compound.

For a compound to dissolve, the solvation energy that the fluid would use to work on its ions must exceed the compound's lattice energy. Hence, the higher the lattice energy, the less soluble the compound would be.

B) The 'like dissolves like' law in dissolution is very true and applicable. The law explains that polar compounds will dissolve in polar solvents and not dissolve in non-polar solvents. Only non-polar compounds will dissolve in non-polar solvents.

Ionic compounds contain positive and negative ions, making them one of the most polar sets of compounds. So, they will easily dissolve in polar solvents.

C) Enthalpies of hydration of the cations and anions represent the total enthalpy of dissolution. This is the energy released when a compound undergoes hydration. A form of salvation of the ions, the enthalpy of hydration need to match or exceed the lattice energybof the compound For the compound to be soluble. Hence, the larger the enthalpies of hydration, the more likely the compound will be soluble.

Hope this Helps!!!

Answer:

For an electron in 5p orbital

5,1,-1,+1/2

For an electron in 6d orbital

6,2,-2,+1/2

Explanation:

The term quantum numbers refers to a set of values that can be used to determine the region in space where it is likely to find an electron. This region in space where there is a high probability of finding an electron is known as an atomic orbital. An atomic orbital is actually a wave function according to the Schrödinger wave equation.

There are four quantum numbers used in describing an atomic orbital: the principal quantum number (n), the orbital angular momentum quantum number also called azimuthal or subsidiary quantum number (l), the magnetic quantum number (ml), and the electron spin quantum number (ms).

For a 5p orbital;

n= 5, l= 1, ml= -1,0,1 ms= +1/2 or -1/2

For 6d orbital;

n= 6, l= 2, ml= -2,-1,0,1,2, ms= +1/2 or -1/2

Since we are requested to use a four quantum number description that can be assigned to an electron in these levels;

For an electron in 5p orbital

5,1,-1,+1/2

For an electron in 6d orbital

6,2,-2,+1/2

The options of the question is not given so the options are;

(1) Mn(s)

(2) Cu(s)

(3) Ni(s)

(4) Ba(s)

Answer: Mn(s)

Explanation:

The spontaneous reaction depends on the Eo value. The positive Eo value are spontaneous and the negative Eo values are not spontaneous.

so, here the Eo values are:

Eo Zn2+/Zn = -0.763v

Eo Mg2+/Mg = 2.37v

Eo Mn2+/Mn = -1.18v

Therefore, Eo cell (with Zn as one of the half-cell) =  Eo Zn2+/Zn - Eo Mn2+/Mn

=  -0.763 - (-1.18)

 = 0.417v

Whereas, Eo cell (with Mg as one of the half-cell) =  Eo Mg2+/Zn - Eo Mn2+/Mn

=  -2.37 - (-1.18) = -1.19v

Thus, Mn(s) metal will spontaneously react because it has a positive  Eo value and  Zn2+(aq), but will not spontaneously react with Mg2+(aq) because it has negative Eo value.

Answer:

[Ne]3s²

Explanation:

Mg

1s2 2s2 2p6 3s2   or [Ne]3s²

Abbreviated electronic configuration of magnesium is [Ne]3 s² and in complete form it is 1 s² 2 s² 2 p⁶ 3 s².

Electronic configuration is defined as the distribution of electrons which are present in an atom or molecule in atomic or molecular orbitals.It describes how each electron moves independently in an orbital.

Knowledge of electronic configuration is necessary for understanding the structure of periodic table.It helps in understanding the chemical properties of elements.

Elements undergo chemical reactions in order to achieve stability. Main group elements obey the octet rule in their electronic configuration while the transition elements follow the 18 electron rule. Noble elements have valence shell complete in ground state and hence are said to be stable.

Learn more about electronic configuration,here:

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Answer:7.1

Explanation:

m1=v1

m2=v2

let m2 be x

4.0=450

x=800

cross multiply

4.0 x 800=450x

3200=450x

x = 3200/450

x=m2=7.1

Answer: The concentration of NaOH solution is 0.194 M

Explanation:

To calculate the number of moles, we use the equation:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]

Given mass of KHP = 0.294 g

Molar mass of KHP = 204.22 g/mol

Putting values in above equation, we get:

[tex]\text{Moles of KHP}=\frac{0.294g}{204.22g/mol}=0.00144mol[/tex]

The chemical reaction follows the equation:

[tex]KHC_8H_4O_4(aq.)+NaOH\rightarrow KNaC_8H_4O_4(aq.)+H_2O(l)[/tex]

By Stoichiometry of the reaction:

1 mole of KHP reacts with 1 mole of NaOH.

So, 0.00144 moles of KHP will react with = 0.0144 of KOH.

To calculate the molarity of NaOH, we use the equation:

[tex]\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}[/tex]

We are given:

Moles of KOH = 0.00144 moles

Volume of solution = 7.42ml  = 0.00742L      (Conversion factor:  1L = 1000 mL)

Putting values in above equation, we get:

[tex]Molarity=\frac{0.00144mol}{0.00742L}=0.194M[/tex]

Hence, the molarity of NaOH solution is 0.194 M

The concentration of the NaOH solution used in complete titration has been 0.194 M.

The reaction of KHP with NaOH has been the neutralization reaction that results in the formation of salt and water.

The concentration of KHP solution has been:

Molarity = [tex]\rm \dfrac{weight}{Molecular\;weight}\;\times\;\dfrac{1000}{Volume\;(ml)}[/tex]

Molarity of KHP = [tex]\rm \dfrac{0.294}{204.2}\;\times\;\dfrac{1000}{250}[/tex]

Molarity of KHP = 0.0057 M

The concentration of the KHP solution has been 0.0057 M.

For the neutralization reaction in complete titration:

Molarity of acid [tex]\times[/tex] Volume of acid = Molarity of base [tex]\times[/tex] Volume of base

Substituting the values from the question:

0.0057 M [tex]\times[/tex] 250 ml = Molarity of NaOH [tex]\times[/tex] 7.42 ml

1.439 = Molarity of NaOH [tex]\times[/tex] 7.42 ml

Molarity of NaOH = 0.194 M.

The concentration of the NaOH solution used in complete titration has been 0.194 M.

For more information about complete titration, refer to the link:

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