题库网 (tiku.one)

 找回密码
 立即注册

 

      

上传图片附件

未使用图片

小贴士: 允许的图片文件格式为: gif, jpg, jpeg, png, webp,上传完成后会在上方生成预览,用鼠标连续双击缩略图,或拖动缩略图,该图片就被绑定至本题,显示在题目下方

本次作答已使用

小贴士: 此栏目显示的是当前作答使用的所有图片,绑定到某一题目的图片同时会显示在该题目下方; 删除使用的图片会将其转移到<未使用图片>类别


习题练习:Models of Bonding & Structure B.2 The Covalent Model



 作者: admin   总分: 66分  得分: _____________

答题人: 匿名未登录  开始时间: 23年07月06日 14:28  切换到: 整卷模式

标记此题
1#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The molecule $O_2$ contains one σ and one π bond. How do p orbitals in the O atoms overlap to produce the π bond?

参考答案:     查看本题详细解析

标记此题
2#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which correctly states the relative size of the bond angles for $H_2O$, $NH_3$, and $CH_4$?

参考答案:     查看本题详细解析

标记此题
3#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The halogens can be found in group 17 and exist as diatomic molecules.

1.State the intermolecular forces present in all of the halogens in their standard states.
2.Predicte the trend in boiling point    group 17 by referring to the relative strengths of their intermolecular forces.
3.Iodine monochloride (ICL) has a very similar molecular mass to bromine ($Br_2$).
State the intermolecular force present in ICl that is not present in ($Br_2$).
Based on your answer to part (a) of this question, whether the boiling point of lICl will be    to that of ($Br_2$).



参考答案:     查看本题详细解析

标记此题
4#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which bond is more polar?

参考答案:     查看本题详细解析

标记此题
5#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Carbon tetrachloride has covalent bonding. Which of the following clearly describes this type of bonding?

参考答案:     查看本题详细解析

标记此题
6#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  $CH_3COOH$ has which of the following intermolecular forces?

I.London
II.Dipole-Dipole
III.Hydrogen bonds

参考答案:     查看本题详细解析

标记此题
7#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which shows the oxygen-to-oxygen bonds in order of increasing average bond enthalpy?


参考答案:     查看本题详细解析

标记此题
8#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which of the below gives the intermolecular forces in water in the correct order from weakest to strongest?

参考答案:     查看本题详细解析

标记此题
9#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  
Covalent bonds result from the overlap of atomic orbitals.
Which of the following atomic orbitals would overlap to produce a �σ bond in the orientation shown?


参考答案:     查看本题详细解析

标记此题
10#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which is a correct description of the bonding present in the following allotropes of carbon?

参考答案:     查看本题详细解析

标记此题
11#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Ethyne has the molecular formula $C_2H_2$. Which of the following best illustrates the arrangement of hybridized valence orbitals in each carbon atom?



参考答案:     查看本题详细解析

标记此题
12#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The graph below shows the boiling points of some of the group 15 hydrides.


1.State the weakest intermolecular force present in all of the hydrides.
2.Explain the trend in boiling point from $PH_4$ to $SbH_3$.Refer to all intermolecular forces present.
3.Predict the boiling point for $NH_3$ by the graph. > > >  .
4.Justify your predicted boiling point for $NH_3$ in part (c).

参考答案:     查看本题详细解析

标记此题
13#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which of the following statements regarding silicon dioxide, $SiO_2$, are correct?

I.The structure is described as a giant covalent structure with a tetrahedral arrangement
II.The structure is insoluble in water and has a high melting point
III.The structure has a pair of nonbonding electrons present on the silicon atoms

参考答案:     查看本题详细解析

标记此题
14#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The valence electrons in [size=1.21em]I2IX2​ are farther from their nuclei than the valence electrons in [size=1.21em]Cl2ClX2​. Explain how the size of the atoms in a covalent bond can affect the relative attraction to electrons and hence the bond's polarity.
2.Calculate the electronegativity differences in the following compounds $Cl_2$,HCl,and NaCl
(Refer to Table 8 from the data booklet) .

$Cl_2$:the electronegativity difference is   ,
HCl:the electronegativity difference is   ,NaCl:the electronegativity difference is  
$Cl_2$,HCl,and NaCl (Refer to Table 8 from the data booklet) .

参考答案:     查看本题详细解析

标记此题
15#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which compounds have an ionic lattice in the solid state?

I.Ammonium sulfate
II.Hydrogen chloride
III.Sodium carbonate

参考答案:     查看本题详细解析

标记此题
16#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A carbon atom is $sp^2$ hybridized.
Which diagram best illustrates the valence electron configuration of this carbon atom?



参考答案:     查看本题详细解析

标记此题
17#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which statement explains the high boiling point of $NH_3$?

参考答案:     查看本题详细解析

标记此题
18#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  
Which of the following substances is the most soluble in water, with the correct reason given?


参考答案:     查看本题详细解析

标记此题
19#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which of the following has covalent bonding?

I.$CCl_4$
II.$Ca_3N_2$
III.$NH_3$

参考答案:     查看本题详细解析

标记此题
20#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Based on single, double, and triple bonds, which set of molecules is arranged in increasing order of their bond strength?

参考答案:     查看本题详细解析

标记此题
21#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The tetrafluoroborate ion (${BF_4}^-$) is produced when boron trifluoride ($BF_3$) reacts with a fluoride ion.

参考答案:     查看本题详细解析

标记此题
22#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
Graphite is an allotrope of carbon.
  • State two other allotropes of carbon.
    1
  • State the bond angle in graphite and describe the resulting structure.
    2
  • State two properties of graphite resulting from the structure.
参考答案:    

标记此题
23#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which of the following [size=1.21em]cannotcannot conduct electricity in a molten state?

i.$PCl_3$
ii.$NaCl$
iii.$SO_2$

参考答案:     查看本题详细解析

标记此题
24#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Ethene has the following structural formula:


Which orbitals of the carbon atoms are used to form the C-H and C=C bonds of ethene?

参考答案:     查看本题详细解析

标记此题
25#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The electron configuration of carbon is 1${S^2}2{S^2}2{p^2}$ . Why is hybridization helpful for explaining the bonding of carbon in ethene ($C_2H_4$)?[size=1.21em]


参考答案:     查看本题详细解析

标记此题
26#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The Lewis structure of $NCl_3$ is given below. Which type(s) of electrons does it show?

I.Non-Bonding Electrons
II.Bonding Electrons
III.Innermost electrons

参考答案:     查看本题详细解析

标记此题
27#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  
Molecular oxygen ($O_2$) and ozone ($O_3$) in the atmosphere undergo the following decomposition reactions.
The reactions occur when the reactant molecules absorb a specific wavelength of light.
Which of the following statements is true?


参考答案:     查看本题详细解析

标记此题
28#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Based on their structures, which of the substances below is likely to be the most volatile?

参考答案:     查看本题详细解析

标记此题
29#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  There are many different molecules with both carbon and oxygen.

1.Draw the Lewis structures for carbon monoxide, carbon dioxide, and methanol.
2.Arrange in increasing order of bond length the C−O bonds found in the three molecules from part (a).
  <  < 
3.The individual carbon-oxygen bond is    in carbon monoxide than in carbon dioxide.


参考答案:     查看本题详细解析

标记此题
30#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The structures of diamond and buckminsterfullerene are shown.


Which of the following correctly describes the physical properties of the two materials?

参考答案:     查看本题详细解析

标记此题
31#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which molecule would be considered polar covalent?

参考答案:     查看本题详细解析

标记此题
32#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
Hydrogen cyanide consists of a carbon atom bonded to one hydrogen atom and one nitrogen atom.

1.Draw the Lewis structure of hydrogen cyanide.
2.The valence electron configuration of the carbon atom before hybridization is shown.

Hybridization produces a new configuration of valence orbitals, each containing one unpaired electron.
Draw a similar diagram illustrating the valence electron configuration of the carbon atom after hybridization, including labels for the valence orbitals.
3.Hydrogen cyanide contains both σ and π bonds.
1.State the type of bond formed by the hybrid orbitals of the carbon atom.
2.Explain how the π bonding in hydrogen cyanide is produced by the overlap of valence orbitals.
参考答案:     查看本题详细解析

标记此题
33#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
Kekule proposed in 1865 that the structure of benzene was an alternating ring of single and double bonds between 6 carbons.
Discuss whether his structure is accepted, giving physical and chemical evidence. You may refer to the data booklet, in any of tables 10 to 13.
参考答案:    

标记此题
34#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  
The bond angles surrounding atoms 1, 2, and 3 are:


参考答案:     查看本题详细解析

标记此题
35#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The structural formula of methane is shown.


1.The valence orbitals of the carbon atom must be hybridized to produce the bond angle θ。
State the hybridization of the carbon atom in methane  $^3$
State the value of θ in degrees  $^{\circ}$
The angle between the p orbitals of the carbon atom before hybridization is   to θ.
2.Methane contains four C-H bonds.
  • State how the electron density is distributed within each C-H bond.1
  • State how the orbitals of the carbon and hydrogen atoms overlap to produce a C-H bond.1
  • Explain how hybridization affects the pairing and relative energies of the carbon valence electrons to enable the formation of four equivalent C-H bonds.


参考答案:     查看本题详细解析

标记此题
36#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  
Chloroalkanes can be produced in substitution reactions between alkanes and chlorine in the presence of UV light. The reaction between methane and chlorine produces a mixture of four chloroalkanes $CCl_4$,$CHCl_3$,$CH_2Cl_2$,and $CH_3Cl$.
The table below shows the boiling points for $CCl_4$,$CHCl_3$,$CH_2Cl_2$,and $CH_3Cl$.
1.Outline with a reason the relative strengths of the London forces from$CCl_4$ to $CH_3Cl$.
2.Please predicted that the boiling point for$CCl_4$ would be significantly    than that of the other chloroalkanes


参考答案:     查看本题详细解析

标记此题
37#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which of the following molecules would NOT demonstrate resonance?

参考答案:     查看本题详细解析

标记此题
38#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which statement correctly explains why the boiling point of 2-methylpentane is lower than that of hexane?


参考答案:     查看本题详细解析

标记此题
39#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the correct number of total valence electrons and electron domains on the central atom for the methanal molecule,$CH_2O$

参考答案:     查看本题详细解析

标记此题
40#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Two possible oxides of sulfur are sulfur dioxide,$SO_2$, and sulfur trioxide,$SO_3$.

1.1.State the number of electron domains present around the central atom in each sulfur oxide,$SO_2$ and $SO_3$.
1.2.State the molecular geometry of each structure,$SO_2$ has a    shape and $SO_3$ has a    planar shape.
2.Describe and justify the polarity of each structure, $SO_2$ is  and $SO_3$ is  .
3.State,compare with $SO_2$ and $SO_3$ , which structure would have a shorter bond length.  .
4.State the number of resonance structures for $SO_2$ =   ;AND describe what is meant by “delocalized” electrons.

参考答案:     查看本题详细解析

标记此题
41#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which of the below shows the boiling points in the correct ascending order?

参考答案:     查看本题详细解析

标记此题
42#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  
The bonds in ammonia ($NH_3$) are polar covalent.
  • Draw the Lewis structure of ammonia.
  • Explain why the covalent bonds in ammonia are polar.
  • State the molecular geometry of ammonia 
  • The bond angle of ammonia differs from that of the ammonium ion,$NH_3^+$,The bond angle of ammonia is   $^{\circ}$,The bond angle of the ammonium ion is   $^{\circ}$
2.The boiling points of ammonia and the other group 15 compounds are shown.
Explain the variation of boiling points shown in the graph, using section 8 (Section 9- 2025 Syllabus) of the data booklet.


参考答案:     查看本题详细解析

标记此题
43#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Elemental sulfur reacts with fluorine gas to produce a mixture of sulfur fluorides, including $SF_6$ and $SF_4$.

1.The molecular geometry of $SF_6$ can be represented using dash and wedge notation, as shown.

1.State the molecular geometry of SF6$SF_6$,it is   .
2.Using dash and wedge notation, draw the molecular geometry of $SF_4$.
3.Explain why the S-F bonds in $SF_4$ are arranged as shown in your answer to (ii).


2.$SF_6$ reacts with water to produce sulfur trioxide($SO_3$).
$SO_3$ has multiple resonance structures. One resonance structure A is shown.

1.Calculate the formal charge of the S atom in A, the formal charge is   .
2.In a second resonance structure, B, the S atom obey the octet rule.
S atom obeys the octet rule.Draw the second structure of B, including all non-zero formal charges and non-bonding electron pairs.
3.State which resonance structure is preferred, giving a reason for your answer.



参考答案:     查看本题详细解析

标记此题
44#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Hybridization is a system for explaining the changes in orbital energies and electron configurations when atoms form covalent bonds. Which of the following statements are true?

i.Paired electrons in an s orbital may occupy separate $sp^3$ orbitals after hybridization
ii.Hybridization leaves the number of atomic orbitals unchanged
iii.A π bond forms from the sideways overlap of sp or $sp^2$ orbitals

参考答案:     查看本题详细解析

标记此题
45#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The structural formulas of two compounds in a homologous series are shown.


Why does the boiling point of compound Y differ from that of compound X?

参考答案:     查看本题详细解析

标记此题
46#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Properties and behaviors of organic molecules can be inferred using intermolecular forces.
Explain, which of the following pairs will have a higher boiling point:

1. 
2.  .
3.  .

参考答案:     查看本题详细解析

标记此题
47#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which of the following statements regarding the Lewis structure of $BF_3$ is correct?

I. The structure contains a net dipole moment
II.The structure would have bond angles of $120^{\circ}$ with one double bond
III.The structure is considered to be electron deficient

参考答案:     查看本题详细解析

标记此题
48#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  
Molecules of liquid bromine trifluoride (BrF3)($BrF_3$) react with each other to form $BrF_2^+$ and $BrF_4^-$ ions.
Which equation shows the molecular and electron domain geometries of the reactant and products?


参考答案:     查看本题详细解析

标记此题
49#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The formate or methanoate ion,$HCO_2^-$ , is commonly found in living systems, and is part of the synthesis of many amino acids.
1.Determine the number of valence electrons in the methanoate ion; it is   valence electrons.
2.Draw a Lewis structure for the methanoate ion. Include resonance structures if resonance is present in the structure.
3.State the molecular geometry is    planar;AND the bond angles of the methanoate ion=  $^{\circ}$.
4.Justify the existence of a dipole moment in the molecular structure of the methanoate ion.



参考答案:     查看本题详细解析

标记此题
50#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Two common minerals found in sedimentary rocks are calcite and quartz.

1.Calcite has the molecular formula $CaCO_3$ and contains the anion X.
1.1.State the name of anion X; X is   .
1.2.Draw the Lewis structure of anion X. including all atomic charges and bonding and non-bonding electron pairs.
1.3.The molecular geometry of anion X is   .
1.4.Suggest why the bond angles of anion X are all exactly equal.The bond angles are   $^{\circ}$.


2.Quartz has the molecular formula $SiO_2$
2.1.Explain why the bonding in quartz differs from that in calcite based on the electronegativities given in section 8 (Section 9- 2025 Syllabus) of the data booklet.
2.2.Both calcite and quartz can be melted. Explain the electrical conductivities of the two materials after they are melted.
are all exactly equal.


参考答案:     查看本题详细解析

标记此题
51#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which molecule does NOT have a linear shape?

参考答案:     查看本题详细解析

标记此题
52#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
The oxides of two period 3 elements, X and Y, react in water according to the equations below.

I.$XO_{2(s)}$+$H_2O_{(l)}$→$H_2XO_{3(aq)}$
II.$YO_{3(s)}$+$H_2O_{(l)}$→$Y(OH)_{2(aq)}$
Identify elements X and Y. Justify your response.
Predict whether element X or Y would have a higher melting point. Justify your prediction.
参考答案:     查看本题详细解析

标记此题
53#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Formamide has two resonance structures. One resonance structure A is shown.


1.Define the term resonance structures.
2.The hybridization of the nitrogen atom in resonance structure A is   $_3$.
3.In the alternative structure B, the hybridization of the nitrogen atom is different.
Draw resonance structure B, including any non-zero formal charges and non-bonding electron pairs.
4.A 3D model of formamide is shown below:


Choose which resonance structure    better represents the molecular geometry of formamide.

参考答案:     查看本题详细解析

标记此题
54#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Phosphorus reacts with oxygen to form two different oxides, phosphorus(III) oxide ($P_4O_6$) and phosphorus(VI) oxide ($P_4O_{10}$)

1.The oxides of phosphorus consist of cage-like molecules with the following structural formulas.

The O−P−O bond angles in the two molecules are labelled.
1.State the geometries of the bonds around each phosphorus atom in $P_4O_6$   
2.State the geometries of the bonds around each phosphorus atom in $P_4O_{10}$   
3.Suggest why the bond OP−O bond angles of the two molecules are similar despite the different arrangements of bonding and non-bonding electrons around the phosphorus atoms.
4.Explain how the ability of phosphorus to form both $P_4O_6$ and $P_4O_{10}$ demonstrates that the octet rule is not always obeyed.
2.$P_4O_6$ and $P_4O_{10}$ react with an aqueous base to produce phosphite ($HPO_3^{2-}$) and phosphate ($PO_4^{3+}$) ions, respectively. The structural formulas of $HPO_3^{2-}$ and $PO_4^{3+}$ are shown.

State why resonance structures are needed to accurately represent the bonding in $HPO_3^{2-}$ and $PO_4^{3+}$.





参考答案:     查看本题详细解析

标记此题
55#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
Ethanoic acid has a boiling point of 118$^{\circ}$ and is soluble in water.

The structural formula of ethanoic acid is shown.

1.State the strongest type of intermolecular interaction formed by ethanoic acid.
2.The condensed structural formulas of two other organic compounds, A and B, are shown.

1.Explain why the boiling points of A and B differ from that of ethanoic acid.
2.Suggest why the boiling points of A and B are different.
3.Explain why A and B are not soluble in water.
3.When ethanoic acid dissolves in water, it reacts to form an ethanoate ion. The structural formula of the ethanoate ion is shown.

1.Write an equation showing the resonance in the ethanoate ion. Include in it, the structural formulas for the two resonance structures, showing all formal charges and non-bonding electron pairs.
2.Explain how the dissolution of ethanoic acid in water affects the electrical conductivity of the liquid.
参考答案:    

标记此题
56#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  In a $CO_2$ molecule, how many lone and bonding pairs of electrons are present in the Lewis-dot structure?




参考答案:     查看本题详细解析

标记此题
57#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The difference in physical properties of the following using knowledge of chemical structure and bonding:

1.The boiling point of hydrochloric acid (HCl) is    than that of lithium chloride (LiCl).
2.Calcium bromide ($CaBr_2$) can conduct electricity in a molten state and aqueous solution, Please judge bromine ($Br_2$)   .
3.The boiling point of HI is    than $I_2$.
Arrange bromine $Br_2$ potassium and potassium bromide in order of increasing boiling points.       .

参考答案:     查看本题详细解析

标记此题
58#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The structural formula of beryllium hydride is shown.

H-Be-H
Which diagram best illustrates the valence electron configuration of the beryllium atom after hybridization?




参考答案:     查看本题详细解析

标记此题
59#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Gaseous aluminium chloride has the molecular formula $AlCl_3$.

1.By counting the valence electrons of the Al atom, explain why $AlCl_3$ is described as electron deficient.
2.Aluminium chloride changes from a gas to a solid when it is cooled. The molecules of $AlCl_3$ dimerise to form $Al_2Cl_6$,which has the following structural formula.

1.Calculate the formal charge of each aluminium atom in $Al_2Cl_6$,Formal charge =-   or   -.
2.State how the molecular geometry around each aluminium atom changes when $AlCl_3$ dimerises to form $Al_2Cl_6$.In $AlCl_3$ is   geometry ;In $Al_2Cl_6$ is   geometry.
3.Iodine trichloride also forms a dimeric structure. The structural formula of the $I_2Cl_6$ dimer is shown.

1.Explain why the electron domain geometry of the iodine atoms in $I_2Cl_6$ differs from that of the aluminium atoms in $Al_2Cl_6$.
2.Explain how repulsion between the valence electron pairs determines the molecular geometry around each iodine atom.

参考答案:     查看本题详细解析

标记此题
60#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which terms best describe the electron domainelectron domain geometry of $BrCl_5$?




参考答案:     查看本题详细解析

标记此题
61#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which of the following solvents would be suitable choices for the mobile phase in paper chromatography to ensure that a polar dye has a high $R_f$ value?





参考答案:     查看本题详细解析

标记此题
62#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Dimethyl ether and ethanol are both organic liquids that are soluble in water. Dimethyl ether has limited solubility, whereas ethanol is soluble in water in all proportions.


1.Use the diagrams above to explain the differences in solubility of dimethyl ether and ethanol in water.
2.Predict the relative solubility of chloroethane in water, compared to dimethyl ether and ethanol.
The relative solubility of chloroethane  dimethyl ether and ethanol

参考答案:     查看本题详细解析

标记此题
63#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  



3.Amino acids such as glycine can be used to produce long molecules called peptides. The shape of the peptide molecule is determined by the types of intermolecular interactions present between the amino acid side chains, which have different structures. Part of a peptide molecule is shown, with the side chains highlighted in bold.

Suggest why acid-base reactions could alter the shape of this peptide chain.
参考答案:    

标记此题
64#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which row(s) show(s) the correct interactions between the substances and water?


参考答案:     查看本题详细解析

标记此题
65#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The Lewis structure of the nitrite ion is shown.


What is the hybridization of the N atom and the most likely value of the bond angle in the nitrite ion?



参考答案:     查看本题详细解析

标记此题
66#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Boron nitride is a solid material with a layered giant covalent structure. The structure of one layer of boron nitride is shown.

The structure of boron nitride is similar to that of a carbon allotrope.
1.Define the term allotropes.
2.State the name of the carbon allotrope that is structurally similar to boron nitride.The name is  
3.Explain why the B atoms in boron nitride may be described as electron-deficient.
4.The N atoms in boron nitride form bonds with equal lengths and bond angles of 120$^{\circ}$.
1.The electron domain geometry around the N atom is   .
2.Explain why the geometry named in (i) suggests that boron nitride contains dative covalent (coordination) B-N bonds.
3.Explain why the B-N bonds have equal lengths, despite the presence of the additional covalent bond named in (ii).
5.The layers of boron nitride are stacked as shown.

Boron nitride is    than the carbon allotrope named in (b).





参考答案:     查看本题详细解析

  • :
  • 总分:66分 及格:39.6分 时间:不限时
    未答题: 已答题:0 答错题:
    当前第 题,此次习题练习共有 66 道题
    本系统支持习题练习,作业与考试三大模式,作业考试自动评分,成绩排序一键导出,可设定动态变量同一试卷千人千题
    如果您对本系统感兴趣,想加入我们或者想进行任何形式的合作,请加微信 skysky1258

    浏览记录|使用帮助|手机版|切到手机版|题库网 (https://tiku.one)

    GMT+8, 2024-12-26 15:48 , Processed in 0.361383 second(s), 153 queries , Redis On.