Atomic size increases down a group in the periodic table.

Question

ScanSolve AI Tutor · Accepted Answer

Here are the solutions to the questions:

1) B) Ba > Mg

Atomic size increases down a group in the periodic table.
Barium (Ba) is below Magnesium (Mg) in Group 2.
Therefore, Ba has a larger atomic radius than Mg.
2) D) Mg $^{2+}$
Heat of hydration is directly proportional to ionic charge and inversely proportional to ionic size.
Among the given ions, Mg $^{2+}$ has the highest charge (+2) and is relatively small compared to Ba $^{2+}$ , Na $^+$ , and Cs $^+$ .
Smaller size and higher charge lead to stronger electrostatic attraction with water molecules, resulting in a higher heat of hydration.
3) B) B
Tincal is a natural mineral.
Its chemical formula is Na $_2$ B $_4$ O $_7 \cdot 10$ H $_2$ O, which is hydrated sodium borate.
This mineral is a primary source of Boron.
4) B) N $_2$ O
Laughing gas is the common name for dinitrogen monoxide.
The chemical formula for dinitrogen monoxide is N $_2$ O.
5) B) Cl $_2$ O $_7$
An acid anhydride is formed by removing water from an acid molecule.
For perchloric acid (HClO $_4$ ), two molecules combine to lose one water molecule
$2\text{HClO}_4 - \text{H}_2\text{O} \rightarrow \text{H}_2\text{Cl}_2\text{O}_8 - \text{H}_2\text{O} = \text{Cl}_2\text{O}_7$
Therefore, the anhydride of HClO $_4$ is Cl $_2$ O $_7$ .
6) D) Co
A typical transition metal forms at least one ion with a partially filled d subshell.
Scandium (Sc) and Yttrium (Y) form Sc $^{3+}$ and Y $^{3+}$ ions, which have empty d-orbitals.
Radium (Ra) is an alkaline earth metal.
Cobalt (Co) forms ions like Co $^{2+}$ ([Ar]3d $^7$ ) and Co $^{3+}$ ([Ar]3d $^6$ ), both of which have partially filled d-orbitals.
7) C) sp $^2$
The hybridization of atomic orbitals determines the molecular geometry.
sp hybridization results in a linear shape.
sp $^2$ * hybridization results in a planar triangular (trigonal planar) shape.
sp $^3$ hybridization results in a tetrahedral shape.
dsp $^2$ hybridization results in a square planar shape.
8) A) CHCl $_3$
Chloroform is a common organic solvent.
Its chemical name is trichloromethane.
The formula for trichloromethane is CHCl $_3$ .
9) B) NO $_2^+$
Nitration of benzene is an electrophilic aromatic substitution reaction.
The nitrating mixture (concentrated nitric acid and sulfuric acid) generates the electrophile.
The active nitrating agent is the nitronium ion, NO $_2^+$ .
10) D) E $_1$ and SN $_1$
E $_1$ (unimolecular elimination) and SN $_1$ (unimolecular nucleophilic substitution) mechanisms are both two-step processes.
The first step in both E $_1$ and SN $_1$ is the dissociation of the leaving group to form a carbocation intermediate.
11) C) Urease
Fermentation of starch involves enzymes that break down starch into sugars and then ferment those sugars.
Diastase (amylase) breaks down starch.
Zymase ferments sugars. Invertase hydrolyzes sucrose.
Urease* is an enzyme that catalyzes the hydrolysis of urea into ammonia and carbon dioxide.
It is not involved in starch fermentation.

12) C) 40%
Formalin is an aqueous solution of formaldehyde.
It typically contains 37-40% formaldehyde by mass, often with a small amount of methanol as a stabilizer.
The most common concentration is approximately 40%.
13) D) LiAlH $_4$
Reducing a carboxylic acid to an alcohol requires a strong reducing agent.
H $_2$ /Ni and H $_2$ /Pt are catalytic hydrogenation reagents, generally not strong enough for carboxylic acids under typical conditions.
NaBH $_4$ (sodium borohydride) is a mild reducing agent, effective for aldehydes and ketones but not carboxylic acids.
LiAlH $_4$ * (lithium aluminum hydride) is a powerful reducing agent capable of reducing carboxylic acids to primary alcohols.
14) D) Sulphur
Step

Atomic size increases down a group in the periodic table.

Step-by-step solution

Atomic size increases down a group in the periodic table.

Barium (Ba) is below Magnesium (Mg) in Group 2.

Therefore, Ba has a larger atomic radius than Mg.

Heat of hydration is directly proportional to ionic charge and inversely proportional to ionic size.

Among the given ions, Mg2+^{2+}2+ has the highest charge (+2) and is relatively small compared to Ba2+^{2+}2+, Na+^++, and Cs+^++.

Smaller size and higher charge lead to stronger electrostatic attraction with water molecules, resulting in a higher heat of hydration.

Tincal is a natural mineral.

Its chemical formula is Na2_22​B4_44​O7⋅10_7 \cdot 107​⋅10H2_22​O, which is hydrated sodium borate.

This mineral is a primary source of Boron.

Laughing gas is the common name for dinitrogen monoxide.

The chemical formula for dinitrogen monoxide is N2_22​O.

An acid anhydride is formed by removing water from an acid molecule.

For perchloric acid (HClO4_44​), two molecules combine to lose one water molecule

Therefore, the anhydride of HClO4_44​ is Cl2_22​O7_77​.

A typical transition metal forms at least one ion with a partially filled d subshell.

Scandium (Sc) and Yttrium (Y) form Sc3+^{3+}3+ and Y3+^{3+}3+ ions, which have empty d-orbitals.

Radium (Ra) is an alkaline earth metal.

Cobalt (Co) forms ions like Co2+^{2+}2+ ([Ar]3d7^77) and Co3+^{3+}3+ ([Ar]3d6^66), both of which have partially filled d-orbitals.

The hybridization of atomic orbitals determines the molecular geometry.

sp hybridization results in a linear shape.

sp2^22* hybridization results in a planar triangular (trigonal planar) shape.

sp3^33 hybridization results in a tetrahedral shape.

dsp2^22 hybridization results in a square planar shape.

Chloroform is a common organic solvent.

Its chemical name is trichloromethane.

The formula for trichloromethane is CHCl3_33​.

Nitration of benzene is an electrophilic aromatic substitution reaction.

The nitrating mixture (concentrated nitric acid and sulfuric acid) generates the electrophile.

The active nitrating agent is the nitronium ion, NO2+_2^+2+​.

E1_11​ (unimolecular elimination) and SN1_11​ (unimolecular nucleophilic substitution) mechanisms are both two-step processes.

The first step in both E1_11​ and SN1_11​ is the dissociation of the leaving group to form a carbocation intermediate.

Fermentation of starch involves enzymes that break down starch into sugars and then ferment those sugars.

Diastase (amylase) breaks down starch.

Urease* is an enzyme that catalyzes the hydrolysis of urea into ammonia and carbon dioxide.

Formalin is an aqueous solution of formaldehyde.

It typically contains 37-40% formaldehyde by mass, often with a small amount of methanol as a stabilizer.

The most common concentration is approximately 40%.

Reducing a carboxylic acid to an alcohol requires a strong reducing agent.

H2_22​/Ni and H2_22​/Pt are catalytic hydrogenation reagents, generally not strong enough for carboxylic acids under typical conditions.

NaBH4_44​ (sodium borohydride) is a mild reducing agent, effective for aldehydes and ketones but not carboxylic acids.

LiAlH4_44​* (lithium aluminum hydride) is a powerful reducing agent capable of reducing carboxylic acids to primary alcohols.

Still stuck on this one?

More Chemistry Questions

Among the given ions, Mg $^{2+}$ has the highest charge (+2) and is relatively small compared to Ba $^{2+}$ , Na $^+$ , and Cs $^+$ .

Its chemical formula is Na $_2$ B $_4$ O $_7 \cdot 10$ H $_2$ O, which is hydrated sodium borate.

The chemical formula for dinitrogen monoxide is N $_2$ O.

For perchloric acid (HClO $_4$ ), two molecules combine to lose one water molecule

Therefore, the anhydride of HClO $_4$ is Cl $_2$ O $_7$ .

Scandium (Sc) and Yttrium (Y) form Sc $^{3+}$ and Y $^{3+}$ ions, which have empty d-orbitals.

Cobalt (Co) forms ions like Co $^{2+}$ ([Ar]3d $^7$ ) and Co $^{3+}$ ([Ar]3d $^6$ ), both of which have partially filled d-orbitals.

sp $^2$ * hybridization results in a planar triangular (trigonal planar) shape.

sp $^3$ hybridization results in a tetrahedral shape.

dsp $^2$ hybridization results in a square planar shape.

The formula for trichloromethane is CHCl $_3$ .

The active nitrating agent is the nitronium ion, NO $_2^+$ .

E $_1$ (unimolecular elimination) and SN $_1$ (unimolecular nucleophilic substitution) mechanisms are both two-step processes.

The first step in both E $_1$ and SN $_1$ is the dissociation of the leaving group to form a carbocation intermediate.

H $_2$ /Ni and H $_2$ /Pt are catalytic hydrogenation reagents, generally not strong enough for carboxylic acids under typical conditions.

NaBH $_4$ (sodium borohydride) is a mild reducing agent, effective for aldehydes and ketones but not carboxylic acids.

LiAlH $_4$ * (lithium aluminum hydride) is a powerful reducing agent capable of reducing carboxylic acids to primary alcohols.