The element bromine, Br, has a larger atomic radius than A) Cu, O and Ba B) I, Cu, and Ba C) F and Kr D) O, F, and Kr

Answer:

B. 2.12 L  

Step-by-step explanation:

We know we will need a balanced chemical equation with masses and molar masses, so, let's gather all the information in one place.

M_r:                   32.00

        4NH₃(g) + 7O₂(g) ⟶ 4NO₂ + 6H₂O(g)

m/g:                      5.3

(a) Moles of O₂

Moles of O₂ = 5.3 × 1/32.00

Moles of O₂ =0.166 mol

=====

(b) Moles of NH₃

The molar ratio is 4 mol NH₃= 7 mol O₂.

Moles of NH₃ = 0.166 × 4/7

Moles of NH₃ = 0.0946 mol NH₃

=====

(c) Volume of NH₃ at STP

STP is 1 bar and 0 °C. At STP, the molar volume of a gas is 22.71 L.

Volume of NH₃ = 0.0946 ×22.71/1

Volume of NH₃ = 2.15 L

=====

It looks as if you are using the old (pre-1982) definition of STP.

Under that definition, the molar volume of a gas at STP was 22.41 L.

The volume of NH₃ is then 2.12 L.

Answer:

The answer is D, weak bonds require more energy to form than strong bonds.

Explanation:

The correct answer is option B: Weak bonds require less energy to form than strong bonds. This is because the strength of a chemical bond is related to the energy required to break it, not the energy required to form it.

The correct statement regarding the strength of chemical bonds is option B: Weak bonds require less energy to form than strong bonds. The strength of a chemical bond is related to the energy required to break it, not the size of the atoms, temperature, or energy required to form it. A strong bond has a high bond energy because it requires a great deal of energy to break. Conversely, a weak bond, which requires relatively little energy to break, has a low bond energy. This suggests that strong bonds do indeed require more energy to form than weak bonds.

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16) Chemical equation: Ca + H₃PO₄ → Ca₃(PO₄)₂ + H₂.

Oxidation reaction: Ca⁰ → Ca⁺² + 2e⁻ /×3.

3Ca⁰ → 3Ca⁺² + 6e⁻

Reduction reaction: 6e⁻ + 2H₃⁺¹ → 3H₂⁰.

Calcium change oxidation number from 0 to +2 (oxidation) and hydrogen change oxidation number from +1 to 0 (reduction).

Balanced chemical equation: 3Ca + 2H₃PO₄ → Ca₃(PO₄)₂ + 3H₂.

Calcium is stronger reducing agent than hydrogen, gives electrons easier.

This is example of single displacement reaction.

Single displacement is reaction where neutral element metal or nonmetal become an ion as it replaces another ion in a compound.

17) Balanced chemical equation:

3Ca(s) + 2H₃PO₄(aq) → Ca₃(PO₄)₂(aq) + 3H₂(g).

Ionic equation: 3Ca + 6H⁺ + 2PO₄³⁻ → 3Ca²⁺ + 2PO₄³⁻ + 3H₂.

Net ionic equation: 3Ca + 6H⁺ → 3Ca²⁺ + 3H₂.

A spectator ion is an ion that exists as a reactant and a product in a chemical equation.

A spectator ion is phospate anion PO₄³⁻.

Ionic bond is described as the chemical bond between two oppositely charged ions. In ionic bond the metal loses electron forming a positively charged cation and a non metal which accept the cation to form a negatively charged anion. In ionic bond the atoms are held together by electrostatic force of attraction. In ionic bond the anions and cations are present in the ratio where the total charge of the compound becomes zero. For example, Let us consider NaCl compound. An atom of the sodium has three electrons in its valency shell and the electrons are removed from the outer most shell by applying the energy of 5.14 electron volts. The chlorine atom lacks an electron to attain stable electronic configuration and it accepts the electron from the sodium by releasing 3.62 electron volts of energy which means that it takes only 1.52 electron volts of energy to donate an electron to chlorine when both the atoms are far apart. When these electrons are brought together their electric potential becomes more negative. This means that if the neutral sodium and chlorine atoms are found themselves closer it would be energetically favourable to transfer electrons from sodium to chlorine thus resulting in the formation of the ionic bond.

The ions in an ionic bond are held together by electrostatic attraction between the anions and cations in the compound.

For example, sodium chloride [NaCl] (more commonly known as salt) has positively charged sodium [Na+] ions, or cations, and negatively charged chlorine [Cl-] ions, or anions, holding the compound together.

Answer is: hydrogen bonding.

Methanol has stronger intermolecular bonds than methane.

Intermolecular forces are the forces between molecules or particles.

There are several types of intermolecular forces: hydrogen bonding, ion-induced dipole forces, ion-dipole forces andvan der Waals forces.

Hydrogen bond is an electrostatic attraction between two polar groups that occurs when a hydrogen atom (H), covalently bound to a highly electronegative atom such as flourine (F), oxygen (O) and nitrogen (N) atoms.

Answer:

0.726 mol·L⁻¹

Step-by-step explanation:

c = moles/litres

=====

Moles = 29.8 × 1/342.30

Moles = 0.087 06 mol

=====

Litres = 120 × 1/1000

Litres = 0.120 L

=====

c = 0.087 06/0.120

c = 0.725 mol·L⁻¹

1) Answer is: False.

Balanced chemical reaction: Pb + AlCl₃ → no reaction.

The reactivity series is a series of metals from highest to lowest reactivity. Metal higher in the reactivity series will displace another.

Aluminium (Al) is higher in activity series than lead (Pb).

That means aluminium (Al) is stronger reducing agent than lead and gives electrons easier.

This series are used to summarize information about the reactions of metals with acids or water, double displacement reactions (more reactive metals displace metals with lower reactivity) and the extraction of metals from their ores.

2) Answer is: Na3PO4 + 3KOH → 3NaOH + K3PO4, because K retains the same charge throughout the reaction.

This chemical reaction is double displacement reaction - cations (K⁺ and Na⁺) and anions (PO₄³⁻⁻ and OH⁻) of the two reactants switch places and form two new compounds.

Na₃PO₄ is sodium phosphate.

KOH is potassium hydroxide.

NaOH is sodium hydroxide.

K₃PO₄ is potassium phosphate.

3) Answer is: Zn + H2SO4 → ZnSO4 + H2.

Single replacement is reaction where neutral element metal or nonmetal become an ion as it replaces another ion in a compound.

In this balanced chemical reaction zinc (Zn) replaces hydrogen (H).

Zinc changes oxidation number from 0 to +2 (this is oxidation) and hydrogen change oxidation number from +1 to 0 (reduction).

4) Answer is: A single replacement reaction takes place because sodium is more reactive than hydrogen.

Balanced chemical reaction:

2Na(s) + 2H₂O(l) → 2NaOH(aq) + H₂(g).

Single replacement is reaction where neutral element metal or nonmetal become an ion as it replaces another ion in a compound.

In this balanced chemical reaction sodium (Na) replaces hydrogen (H).

Sodium changes oxidation number from 0 to +1 (oxidation) and hydrogen change oxidation number from +1 to 0 (reduction).

5) Answer is: True.

For example, balanced chemical reaction:

Ca + 2HCl → H₂ + CaCl₂.

Reduction hald reaction: 2H⁺ + 2e⁻→ H₂.

Oxidation half reaction: Ca⁰ → Ca²⁺ + 2e⁻.

In this balanced chemical reaction calcium (Ca) replaces hydrogen (H).

In this chemical reaction, calcium lost two electrons (oxidation, change oxidation number from 0 to +2) and hydrogen gain that two electrons (reduction, change oxidation number from +1 to 0).

6) Answer is: It is a single replacement reaction, and the cations in the two ionic compounds are different.

For example, balanced chemical reaction:  

Ba + MgSO₄ → BaSO₄(s) + Mg.

In this balanced chemical reaction barium (Ba) replaces magnesium (Mg), because barium is higher at activity series.

Sulfate anion (SO₄²⁻) is the same in two ionic compounds, but cations (Mg²⁺ and Ba²⁺) changes.

Single Displacement is reaction where neutral element metal or nonmetal become an ion as it replaces another ion in a compound.  

Answer:

106.6 °C  

Step-by-step explanation:

The formula for boiling point elevation ΔTb is

ΔTb = iKb·b

where

i     = the van't Hoff i# factor

Kb = the molal boiling point elevation constant

b   = the molal concentration of the solution

=====

Data

  i = 2, because 1 mol of NaCl gives 2 mol of ions in solution.

Kb = 0.51 °C·mol·kg⁻¹

 b = 1.00/0.155

 b = 6.452 mol·kg⁻¹

=====

Calculations

ΔTb = 2 × 0.51 × 6.452

ΔTb = 6.58°C

 Tb = Tb° + ΔTb

 Tb = 100 + 6.58

 Tb = 106.6 °C

B. Is the Answer 6.022 * 1023

Answer: B) [tex]6.022\times10^{23}[/tex] atoms.

Explanation:

According to the International System of units ,

A mole is basically denotes a unit that contains [tex]6.022\times10^{23}[/tex] of atoms.

It is also known as Avagadro Number.

Similarly,  the number of atoms in one mole of gold = [tex]6.022\times10^{23}[/tex]

hence, the correct answer is B) [tex]6.022\times10^{23}[/tex] atoms.

The modern atomic model is sometimes called the electron cloud , or quantum mechanics model.

So the answer is electron cloud

The answer to this question should be electron cloud.

Answer: 66.66 ml

Explanation: Using Molarity equation:

[tex]M_1V_1[/tex] (stock solution)=[tex]M_2V_2[/tex](solution to be prepared)

given: [tex]M_2=0.750M[/tex]

[tex]V_2=800ml[/tex]

[tex]M_1=9.00M[/tex]

[tex]V_1=?[/tex]

[tex]9.00M\times V_1[/tex] (stock solution)=[tex]0.750M\times 800ml[/tex] (solution)

[tex]V_1= 66.66ml[/tex]

Given:

K = 0.71 = Kp

The reaction of sulphur with oxygen is

                            S(s)   + O2(g)  ---> SO2(g)

initial Pressure                   6.90         0

Change                                -x            +x

Equilibrium                     6.90-x          x

Kp = pSO2 / pO2 = 0.71 = x / (6.90-x)

4.899 - 0.71x  = x

4.899 = 1.71x

x = 2.86 atm = pressure of SO2 formed

temperature = 950 C = 950 + 273.15 K = 1223.15 K

Volume = 50 L

Let us calculate moles of SO2 formed using ideal gas equation as

PV = nRT

R = gas constant = 0.0821 L atm / mol K

putting other values

n = PV / RT = 2.86 X 50 / 1223.15 X 0.0821 = 1.42 moles

Moles of Sulphur required = 1.42 moles

Mass of sulphur required or consumed = moles X atomic mass of sulphur

mass of S = 1.42 X 32 = 45.57 grams or 0.04557 Kg  of sulphur

B. the freedom of electrons in the metallic bonding

Answer: Option (B) is the correct answer.

Explanation:

Copper is known as the best conductor of heat and electricity. This is because in copper there is availability of free electrons.

And, as it is known that electricity is the flow of electrons. This means that since copper metal contains a number of free electrons. Hence, it can easily conduct electricity.

Electronic configuration of copper is [tex][Ar]4s1 3d^{10}[/tex]

Thus, we can conclude that freedom of electrons in the metallic bonding at molecular level property allows copper to be an ideal material to be used in electrical wiring.

Answer: gas and then solid.

Explanation: Just trust me ok.

Answer : The formula unit of Sr & Cl is [tex]SrCl_2[/tex] and the formula unit of Al & S is [tex]Al_2S_3[/tex]

Explanation :

Formula unit : it is defined as the lowest number ratio of ions of an elements in an ionic compound or covalent compound.

For the formula unit of Sr & Cl, two chloride ions[tex](Cl^-)[/tex] are needed to neutralize the one strontium ion[tex](Sr^{2+})[/tex].

For the formula unit of Al & S, three sulfide ions[tex](S^{2-})[/tex] are needed to neutralize the two aluminium ion[tex](Al^{3+})[/tex].

The formula unit of [tex]SrCl_2[/tex] and [tex]Al_2S_3[/tex] are shown below.

Answer: The correct answer is Option a and d.

Explanation: Both the salts are ionic in nature because when dissolved in water, they dissociate into their respective ions.

Ionic compounds are held together by ionic bond. They are neutral compounds as both positive and negative charges neutralize each other. These compounds are also good conductors of electricity because of the presence of ions.

As both the salts have different molecular formula, both of them will have different crystal lattice system and hence, different crystal lattice energy.

From the above information, the correct options are option a and option d.

Answer:

D

Explanation:

both a and b

that i a correct

answer

  Cu + 2HCI → Cu²⁺ + 2CI⁻ + H2(g)

has an overall reduction potential of –0.34 V      

The correct option is:

The reaction is not spontaneous and will require energy to proceed.

Since  the overall reduction potential is negative,the reaction is not spontaneous and it requires energy to proceed.

The reaction is

Cu(s) + 2HCI(aq)  ---> Cu⁺² + 2CI⁻ + H₂(g)

The given E⁰cell = -0.34

The overall reduction potential is negative

A reaction is said to be spontaneous it is ΔG° is negative

The relation between ΔG° and Electrode potential is

ΔG° = -nFE°cell

as given that

E°cell = -0.34 V

The overall value of ΔG° will be positive and hence reaction must be non spontaneous

so

The reaction is not spontaneous and will require energy to proceed.

Isotopes of the same element have identical numbers of protons and electrons (in a neutral state), and thus they share the same atomic number. They differ in the number of neutrons they possess, which leads to different atomic masses.

The question concerns isotopes of the same element. Two key characteristics of isotopes are their atomic number, which remains constant because isotopes have the same number of protons, and their varied atomic mass due to a different number of neutrons.

Isotopes have the same number of protons.

Isotopes have the same number of electrons (if the atom is in a neutral state).

Isotopes have the same atomic number.

Statements about isotopes having the same number of neutrons or the same atomic mass are incorrect; these are the properties that distinguish one isotope of an element from another.

The true statements are:

a) Isotopes have the same number of protons.

b) Isotopes have the same number of electrons.

e) Isotopes have the same atomic number.

Isotopes are variations of the same element that have the same number of protons, but different numbers of neutrons. This means they have different mass numbers, which is the sum of protons and neutrons in the nucleus. Here are the true statements about isotopes of the same element:

Isotopes have the same number of protons: The number of protons (atomic number) defines the element. All isotopes of an element have this same atomic number.

Isotopes have the same number of electrons: In a neutral atom, the number of electrons is equal to the number of protons. Therefore, isotopes of the same element have the same number of electrons.

Isotopes have the same atomic number: Because the atomic number is defined by the number of protons, which is consistent across isotopes of an element, the atomic number remains the same.

D. Same energy level but different sublevel.

There are four quantum numbers [1]:

As their names might suggest:

The two electrons in question come from the same atom. The question suggests that they have the same n, [tex]m_l[/tex], and [tex]m_s[/tex]. As a result, both electrons are in main energy level n = 3. They share the same spin.

However, the two electrons differ in their value of l.

[1] Kamenko, Anastasiya, et. al, "Quantum Numbers", Physical & Theoretical Chemistry, Chemistry Libretexts, 24 Mar 2017.

Since the C is bonded to 2 H atoms,

it needs two more bonds to complete the octet of C(as C forms four bonds in total),hence C-C bond is double covalent bond

The bonded C atom is shown as bold C here:

-C=CH2

The  bond between the two C atoms is Double Covalent.

The type of bond that exists between the two carbon atoms in this organic compound is a double covalent bond.

In a double covalent bond, two pairs of electrons are shared between the two carbon atoms. Each carbon atom contributes one electron from its outermost electron shell to form a strong and stable bond. This sharing of electrons allows both carbon atoms to satisfy the octet rule, which states that atoms tend to gain, lose, or share electrons to achieve a stable configuration with a full outer electron shell, typically containing eight electrons.

Covalent bonds occur when atoms share electrons to achieve a stable electron configuration. In the case of a double covalent bond, there are two pairs of shared electrons between the two carbon atoms. This bond is strong and requires a significant amount of energy to break, making it a key characteristic of many organic compounds with double bonds, such as alkenes and some functional groups in organic chemistry.

To learn more about electrons, click here.

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Heat energy released here

Q = mass x specific heat capacity of water x deltaT

= 25.0 x 4.184 x (-10.0)

= - 1046 Joules

1046 Joules of heat energy is released in this process.  

Answer: The amount of heat released is -1046 J

Explanation:

To calculate the amount of heat released, we use the equation:

[tex]q=mc\Delta T[/tex]

where,

q = heat released = ?

m = mass of water = 25.0 g

c = specific heat capacity of water = 4.184 J/g.°C

[tex]\Delta T[/tex] = change in temperature = [tex]T_2-T_1=(10.0-20.0)^oC=-10.0^oC[/tex]

Putting values in above equation, we get:

[tex]q=25.0g\times 4.184J/g.^oC\times (-10.0^oC)\\\\q=-1046J[/tex]

Hence, the amount of heat released is -1046 J

Momentum = mass x velocity 750x25 = 18750 kg-m/s.

Generally when we move down the group on a periodic table the atomic radii increases as the valency electrons occupy higher levels due to the increasing quantum number. Hence the atomic radii increases down the group.

The ionic radii increases down the group because while we move down the group the elements gain electrons and form ions called anions as an additional electron occupies the orbital the ions get bigger in size. Hence the ionic radii increase.

Electronegativity is described as the ability to attract and bind with electrons and it is a qualitative property. It decreases as we move down the group because the distance between the valency electrons and the nucleus increases. Hence electronegativity decreases down the group.

Reactivity increases as we move down the group as the metals have the tendency to lose electron form its outer shell.

Therefore the answer is ionic radii increases.

Answer: C) Both are made up of monomers that are linked by covalent bonds

Explanation: Polymers are large molecules which are formed by combination of small repeating units called as monomers.

Natural polymers are found in nature such as cellulose whereas synthetic polymers are synthesized in laboratories such as Nylon 6,6.

All the polymers, whether natural or synthetic are made up of monomers and are joined by covalent bonds.

Both natural and synthetic polymers consist of monomers that are linked together by covalent bonds, with natural polymers having a wider variety of monomers like amino acids, and synthetic polymers often containing fewer types of monomers. Option C is correct .

Natural polymers and synthetic polymers are similar in that they are both made up of monomers linked together by covalent bonds. Examples of natural polymers include proteins and DNA, which are fundamental to biological structure and function. Synthetic polymers, on the other hand, include plastics like polystyrene. Option C is correct .

The monomers in natural polymers can vary greatly; there are 20 different amino acids that can combine in a multitude of sequences to form different proteins. Synthetic polymers typically feature fewer types of monomers, but the process of polymerization, which results in the formation of large molecules through the joining of these monomers, is a common characteristic shared by both natural and synthetic polymers.

Proteins are significant examples of natural polymers, functioning as enzymes that catalyze biological reactions. While synthetic polymers do not serve in biological catalysis, their repeating monomer units confer them with unique physical properties making them valuable in a variety of applications.

It will be B.) A force equal to the force keeping the object at rest, but in the opposite direction.

Answer: A) Nonmetal carbon shares valence electrons with each nonmetal chlorine forming four covalent bonds.

Explanation: Covalent bond is formed by sharing of electrons between atoms.

Ionic bond is formed by transfer of electrons between atoms.

Carbon with atomic no 6 and has configuration of [tex]1s^22s^22p^2[/tex]. Carbon has 4 valence electrons. It can only share electrons as it is difficult to gain or lose 4 electrons to complete it's octet.

Chlorine with atomic no 17 has configuration of [tex]1s^22s^22p^3s^23p^5[/tex]. It has 7 valence electrons and need one electron to complete its octet.

Thus carbon will share 4 electrons, one each with four chlorine atoms to form carbon tetra chloride.

Answer:

A

Explanation:

You can solve this by utilizing the ideal gas law, PV=nRT. P is pressure, V is volume, n is the number of moles, R is a constant (depends on the unit of pressure), and T is the temperature (in Kelvins).

500.0mmHg- convert to atm

=0.65789atm (do sig figs last)

25.0 C- convert to K

25.0 +273= 298K

PV=nRT

0.65789atm times 45.0L equals n (the variable) times R (0.08206L atm mol^-1 K^-1) times 298K

Isolate the variable, n and plug into a calculator.

I hope this helped!

Answer: The moles of gas is 1.21 moles.

Explanation:

To calculate the moles of gas, we use the equation given by ideal gas which follows:

[tex]PV=nRT[/tex]

where,

P = pressure of the gas = 500.0 mmHg  

V = Volume of the gas = 45.0 L

T = Temperature of the gas = [tex]25^oC=[25+273]K=298K[/tex]

R = Gas constant = [tex]62.364\text{ L.mmHg }mol^{-1}K^{-1}[/tex]

n = number of moles of gas = ?

Putting values in above equation, we get:

[tex]500.0mmHg\times 45.0L=n\times 62.3637\text{ L.mmHg }mol^{-1}K^{-1}\times 298K\\\\n=\frac{500.0\times 45.0}{62.364\times 298}=1.21mol[/tex]

Hence, the moles of gas is 1.21 moles.

D.!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Answer:

Explanation:

A galaxy cluster is a structure consisting in many galaxies bounded by gravitational forces maintaining their form, many clusters form superclusters galaxies. One of the notable clusters is Virgo cluster on the constellation of Virgo.