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习题练习:Mechanisms of Chemical Change F.1 Proton Transfer Reactions



 作者: admin   总分: 63分  得分: _____________

答题人: 匿名未登录  开始时间: 23年12月21日 21:51  切换到: 整卷模式

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1#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An example of a strong acid solution is nitric acid,eyp1 s .m/+mktb v(eg. Which statement is correct for1/g m(+ ,ymv estbp.ke this solution?

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2#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which of the following statements concerning acids a0 ;-0kkb /rrd *yqc*ixplz sh2;sw s,znd bases is not true?

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3#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which of the following is coruy 8hy ,-8iaagoiy4 r,ayuqdg0fx 8+7 rect?

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4#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which statement about a s3mr :osy:*-( t-nu1wgig kf 1pc,vhzetrong acid and its conjugate base is correct?

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5#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which of the following expressionsa7o+9trt.l9 5phm gf g for $K_w$ is correct?

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6#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which combination of acid and base should be reacted to obtain a/r(ejovkn i),*tagq cij)9v; basic salt?

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7#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A reaction produces carbon dioxide gas and a solution ofz rd/;b6q rch2 water with a dissolved salt. Wha q;d/6h cbr2rzt could be the reactants?

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8#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which combination of acid and base will typically kvpa(21jy xm:ccpys41 u 1u3n have the lowest pH at the equivalence point in a:p4jx ay13cpnvmsc ( k21uyu 1 titration?

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9#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  In order to prepare ap0htcxy:ypj tnb + 8j60q1gg 3 solution of $0.1mol\:dm^{-3}$ with the highest pH, substance XX is dissolved in water. Substance X is

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10#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Water dissociates partiai nm-5kwte )fr1 rmbdto+w c +x1jp8,*lly and the value of the ionic product constant of water+,wict wk-prr1ne1mb5fmd8+ o x j)*t at $25^{\circ}$ is $1.00\times10^{-14}$.
1.State an equation for the dissociation of water.
2.Calculate the pH of a $0.0100mol\:dm^{-3}$ of lithium hydroxide at 298K.  
3.Explain whether a $0.0100mol\:dm^{-3}$ solution of calcium hydroxide will have a higher or lower pH than a $0.0100mol\:dm^{-3}$ solution of lithium hydroxide at the same temperature.  $mol\:dm^{-3}$

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11#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  When wine is exposed to air, the ethanol is slowly converted to ethanoic aci.u zk,ct;nn psqy7 /;id. The \ce{pH}pH of a bottle of wine changes from 6.5 to 4.5.ip7 t; nzsc;ny.,k/qu The concentration of $[H]^+$ is?

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12#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A molecule of HBr reacts with water to produce the chhbhuq)z6 ncba32g./9w *f qfy arged molecule X. What is the )hcqwy bzq b*h3fnf ./ 92gau6Lewis structure of molecule X?



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13#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Alkali solutions can be made by dissolvig,mfkxc+nt-v 4i* byye 8348ylf:yp hng a basic substance in water.
1.Determine the concentration of a solution of NaOH made by carefully dissolving 5.00 g of NaOH in sufficient distilled water to make $250.0cm^3$ total solution in a volumetric flask.  $mol\:dm^{-3}$
2.An indicator was added to the solution made in (a), and it turned red. Using section 22 (Section 18- 2025 syllabus) in the Data booklet, state a possible indicator used.
3.The temperature of a $50.0cm^3$ sample of the solution containing the indicator from (b) was found to be $22.0^{\circ}C$. Suggest with a reason, two possible observations if a slightly larger quantity of HCl was added and stirred.
Important note: The section numbers mentioned in the video solution are specific to the 2024 syllabus.
You can refer to the question stem to find the section numbers for the 2025 syllabus.

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14#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An aqueous solution of :y c.b3u 1v:b knt.oeenitric acid $HNO_3$ has a pH of 4. How many moles of this acid are found in $1 dm^3$ of the solution?

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15#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which one of the following statementmv gix0 v42vb wywt0j9syz3lwl5c9 9i59gh . xs about acids is/are true?
|. Acids will neutralize bases to form salts
||. Acids produce solutions with pH greater than 7
|||.Acids ionize to form $H^+$ ions when dissolved in water

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16#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What statements about indja a3hi2v- 2kgicators are correct?
|.Indicators are typically weak acids or weak bases
||.Indicators are different colours in acidic and alkaline conditions
|||.The midpoint of the colour change of an indicator occurs when [$HIn$] = [$In^-$]

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17#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A solution of $1.0\:mol\:dm^{-3}$ HCl is diluted to $0.1\:mol\:dm^{-3}$. Which statement is correct?

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18#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which expression represet9 ypwtu/*4l5dqppr :nts $K_a$ for $CH_3COOH$?

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19#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Given the following indicators and their behaviours, what wi 2glucpu0vpu5 v37f 0gll be the correct colc g fu5l3 0ppu27uv0vgours of a solution of 1.0 M KOH tested with each indicator?
Indicator pH range Colour change (Acid- alkali)
Methyl orange 3.1- 4.4 Red – Orange
Bromocresol green
3.8 - 5.4
Yellow - Blue
Phenolphthalein 8.3 - 10.0 Colourless - Pink


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20#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the order of increa*aj p)7tox 5y it2c(pjjf19 rasing acid strength based on the $pK_a$ values below?
Acid $pK_a$
$CCI_3COOH$ 0.66
$HCOOH$ 3.75
$C_6H_5OH$ 9.99
$CH_3OH$ 15.5


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21#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The structure of the hydrogen phosp:h 5k,fgl3:otd;;mgadl.r u uhate ion is shown.


How many $H^+$ ions can react with one hydrogen phosphate ion?^+ions can react with one hydrogen phosphate ion?

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22#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Place the following )rjex , gzn,dpd*0 6kz$1.0\,mol\:dm^{-3}$ solutions in order of increasing pH:
$NaOH,Na_2CO_3,NaCl$

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23#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which of the following reacticbt9o7m j v3y,ons is not a neutralization reaction?

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24#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
One example of an important buffer system is th)1vksm /e3 zb opi4h3ge $H_2CO_3/HCO_3^-$ buffer in our blood.
1. 1.Define buffer solution.
2.Using relevant equations, describe how the $H_2CO_3/HCO_3^-$ buffer works.
A student has solutions of $0.5\,mol\,dm^{-3}$ $NaOH,HCl,H_2CO_3andNaHCO_3$.
2.State two ways the $H_2CO_3/HCO_3^-$buffer can be made from these solutions.
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25#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The reversible reaction bly6+-nj1 :ip +x2bnisyfj2 bmetween $NH_3$ and $H_2SO_4$ is:
$NH_3 + H_2SO_4 \rightleftharpoons NH^+_4 + HSO_4^-$
Which compounds act as bases in the forward and backward reactions?

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26#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the pH of a 1hq)j 1mcfr.ten(p0:md 8amqw;(r nk$0.001\,mol\,dm^{-3}$ aqueous solution of KOH at 298K given that it ionizes completely?

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27#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
Consider the following reaction:pfna0( el24f 6y3ws y9 u+e7-qmuaspw
$H_2SO_4(aq) + NH_3(aq) \rightleftharpoons HSO_4^-(aq) + NH^+_4(aq)$
1. 1.Define a Brønsted-Lowry acid and a Lewis acid.
2.Deduce the two species acting as acids and their conjugate bases in the equation above.
2.Give an example of a species that is a Lewis acid but not a Brønsted-Lowry acid and explain why this is the case.
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28#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which of the following solutions, when mixed with equal volumes at fjt ,.8 edmg5e+dpe9wequal concentrat8g dt9d,pemef+5.jweions, form a buffer solution?

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29#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  $10\,cm^3$ of an aqueous solution of HCl with pH 1.0 is mixed with $990\,cm^3$ of water. The pH of the formed solution is:

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30#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  $20\,cm^3$ of $0.100\,mol\,dm^{-3}$ NaOH were slowly added to a $10\,cm^3$ sample of $0.100\,mol\,dm^{-3}$ HCl,and the pH was measured throughout the addition.
The equation for the reaction is as follows: $NaOH(aq) + NCl(aq) \rightarrow NaCl(aq) + H_2O(l)$
The ionic product constant of water at $25^{\circ}C$ is $1.00\times10^{-14}$
1.Calculate the number of moles of NaOH remaining at the end of the addition.Mole ratio is 1:1 and NaOH is in excess by  $\times10^{-3}\,mol$
2.Calculate the concentration of $OH^-$ at the end of the addition.  $mol\,dm^{-3}$
3.Using your value for $[OH^-]$ in (b), calculate the pH of the solution at the end of the addition.  

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31#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Concentrated sulfuric acidg)bhzbx 0,hp+dg-a c 7o5kq 2w behaves as a strong acid when it reacts with water:
$H_2SO_4(aq) \rightarrow H^+(aq) + HSO^-_4(aq)$
$HSO_4^- \rightleftharpoons H^+(aq) + SO_4^{2-}(aq)$
Which of the following is (are) true for $1.0\,mol\,dm^{-3}$ of sulfuric acid?
I.$[H^+]$ is high
II.$[SO_4^{2-}]$ is high
III.$[SO_4^{2-}] = [HSO^-_4]$

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32#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which indicator would be most suitable for a titration between sodium 1byede:u:e5 d: xo *x99)jad g6 qpjprhydroxide and ethanoic *opxj: p)j dd9bq6 yduee5e:x:g9r1a acid?
Indicator pKa
Methyl orange 3.7
Bromocresol green 4.7
Bromothymol blue 7.0
Phenolphthalein 9.6


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33#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which statements are corret ll92jm,i0pw g;g25i 4khjihjzqx:4bc 02tpct?
I.$CH_3NH_2$ is a Lewis base
II.HOOCCOOH is a Bronsted-Lowry acid
III.$CH^+_3$ is a Lewis acid

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34#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Methanoic acid HCOOH is a weak covky:muf vx*bumtx 45rc/ dnz28 +97 acid.
1.State the formula of the conjugate base of HCOOH.
2.HCl is a strong acid and dissociates in water as shown below:
$HCl(aq) \rightarrow H^+(aq) + Cl^-(aq)$
1.Suggest the pH of the solution formed when HCl dissolves in water.
2.Compare the relative strengths of the respective conjugate bases of HCOOH and HCl.\ce{pH}pH value less than  
3.$0.01\,mol\,dm^{-3}$ of a given monoprotic acid HA has a pH of 3.
1. This acid is   .
2.Compare the electrical conductivity of HA(aq) and $HNO_3(aq)$, giving a reason for your choice.

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35#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which statement about the equivalence point of acid-base titrations is incorr zqm0idsikv5,/ssy52 ect?ss, vz m25idys/0kiq5

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36#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which of the following salts form basic solutions when 6t 2,05gpk liiml*c isfzl,l3 dissolved in water?
I.$NH_4Cl$
II.$K_2CO_3$
III.$NaOOCCH_3$

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37#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which of the following combinationsk23mmtxe/g l 8 of $NH_3(aq)$ and HCl(aq) forms a buffer solution?

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38#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The correct sequence inm kkw(cf8j cw2y*+ r-l decreasing order of pH for equimolar solutions is:

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39#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which of the three oxides of peri y-s, k7 i4/axpxznq8fod 3 below will cause a change in the pH of the soxyzaqi 4pnkfs/x7-8 ,lution when they react with water?
I.$Na_2O$
II.$SiO_2$
III.$P_4O_{10}$

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40#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
1. 1.Differentiate betweem3dc1 4u z(dg 1gfoqd4n a strong acid and a weak acid.
2.State a balanced equation for the reaction between KOH and $HNO_3$.
Measuring the pH can be useful when trying to differentiate between different solutions.
A student has three unlabelled bottles of white powders. They know that the bottles contain either $KOH,KOOCCH_3 or HNO_3$.The student has access to a pH meter and distilled water.
2.Outline how the student can determine which powder is inside each of the three unlabelled bottles. Include equations where relevant.
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41#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Four features of theld gu c nq;*ay0qf9k(5 $HNO_3$ molecule are labelled a-d.

Why is one mole of $HNO_3$ able to react with one mole of NaOH?

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42#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which of the following statements about pH is inc)p8s+ 7rkq wxforrect?

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43#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
Ethanoic acid reacts with trimethylamine to produce a negatively charged ethankt e8p .vz*.+iq nr4kxoate *t r. nk4.qv ezkxpi+8ion and another charged compound X.


1.Ethanoic acid and the ethanoate ion differ by one hydrogen ion. State the name given to a pair of molecules that differ in this way.
2.State why trimethylamine is categorised as a Brønsted-Lowry base.
3.Ethanoic acid can be represented as $CH_3COOH$. This formula provides a better description of the bonding in the molecule than the alternative formula $CH_3CO_2H$.
1.Suggest why it is better to represent the structure of ethanoic acid as $CH_3COOH$ than as $CH_3CO_2H$.
2.The formula of compound X is $(CH_3)_3NH^+$.Draw the structural formula of compound X.
4.Water can react with both ethanoic acid and trimethylamine.
1.The reaction of water with ethanoic acid produces an ethanoate ion and another charged compound Y. State the formula of compound Y.
2.State the property of water and trimethylamine that allows them both to react with Brønsted-Lowry acids.
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44#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which of the following acid-base pairs( vcfz/r7vies5h. kmsb;8:ke are correctly matched with the salt formed from thei(kz cki.v5fmse8 ve:;rh 7b/sr reaction?

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45#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
This question is about the weak acid, carbonic aci0s*i8 sm f 4prb6i)ocsd $H_2CO_3(pK_{a1} = 6.35)$.
1. 1.Determine the pH of a $0.175\,mol\,dm^{-3}$ solution of carbonic acid.
2.State one assumption made in your answer to (a)(i).
Carbonic acid is a diprotic acid so can undergo two dissociations. The second dissociation has a $pK_{a2}$ of 10.33.
2. 1.State the equation for the second dissociation of carbonic acid.
2.Comment on the degree of dissociation for this second proton, based on the value of $pK_{a2}$.
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46#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Indicators are used to determine the endpoint of a titj.6xpq-z*kwq0dpip) jriqcp r ;1* x2ration.
1.Using a relevant equation, explain how acid-base indicators work.
2. 1.Calculate the pH of a $1.0\,mol\,dm^{-3}$ solution of KOH.pH=  
2.Calculate the pH of a $0.5\,mol\,dm^{-3}$ solution of $HNO_3$.pH=  
3.Using section 22 (Section 18- 2025 Syllabus) of the data booklet, suggest a suitable acid-base indicator for a titration between the solutions in (b)(i) and (b)(ii).
4.On the following axis, sketch the titration curve for the titration between the solutions in (b)(i) and (b)(ii), starting with $10\,cm^3$ of $HNO_3$ solution in the flask, and titrating with KOH.



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47#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Commercial vinegar contains a small percentage of et+9 iu+:5gq/kuh sc ssfhanoic acid. A student wishes to duiu: +5 kfss+/qhsc 9getermine the concentration of ethanoic acid in vinegar. She titrates a solution of ethanoic acid against a standard solution of potassium hydroxide of concentration $8.0\times 10^{-4}\,mol\,dm^{-3}$. The equation for the reaction is:
$CH_3COOH(aq) + KOH(aq) \rightarrow CH_3COOK(aq) + H_2O(I)$
A volume of $25.0\,cm^3$ of vinegar was diluted with distilled water and made up to a volume of $250.0\,cm^3$ in a volumetric flask. A burette was filled with the diluted solution.
$25.0cm^3$ of potassium hydroxide solution was added to a conical flask and three drops of phenolphthalein indicator added.
1.Ethanoic acid is considered a weak acid. Define the term ‘weak acid’.
2.The results of the titration are shown in the table below:
Trial Volume of Titre$(cm^3)$
1 21.0
2 21.2
3 20.8

1.Using section 22 (Section 18- 2025 Syllabus) of the IB data booklet, identify the color at the endpoint.
2.Calculate the concentration of dilute ethanoic acid.  
3.Calculate the concentration of ethanoic acid in vinegar.  $\times10^{-4}\,mol\,dm^{-3}$
Important note: The section numbers mentioned in the video solution are specific to the 2024 syllabus.
You can refer to the question stem to find the section numbers in the 2025 syllabus.

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48#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which of the following equations is not an acid-base reactio s .duonzt1dc-wpiq6.s)y4;mn according to the Bro.1t6dm- ) .ys4zcqp;wd nsuionsted-Lowry theory?

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49#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
Zinc(II) oxide reacts with hydrochlorc; k1tkqfn49 ;dmuf6oic acid to produce an aqueous solution of zinc and chlou;1 f4km6nf9 qkdt ;ocride ions.
$ZnO(s) + 2HCl(aq) \rightarrow Zn^{2+}(aq) + 2Cl^-(aq) + H_2O(I)$
1.HCl is described as an acid because it is a hydrogen ion donor. State the term used to describe acidity of this type
2.State the conjugate base of HCl in this reaction, giving a reason for your answer.
3.An aqueous solution of HCl does not contain molecules of HCl. Draw the structural formula of the positively charged molecule formed in the solution, including the positive charge.
4.Zinc(II) oxide is amphoteric.
1.Define the term amphoteric.
2.Suggest a reaction that could be performed to confirm that zinc oxide is amphoteric, giving your reasoning.
3.Explain why zinc(II) oxide is not amphiprotic.
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50#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
$H_2O$ is an example of an amphiprotic species meaning it can act as either an acid or base.
1. 1.Draw the Lewis structure of $H_2O$.
2.Explain why $H_2O$ can act as both a Brønsted-Lowry acid and Brønsted-Lowry base.
3.Explain why $H_2O$ can act as a Lewis base.
2. 1.State an example of an acid-base reaction where $H_2O$ acts as a Brønsted-Lowry acid and another where $H_2O$ acts as a Brønsted-Lowry base.
2.State an example of a Lewis acid-base reaction that is not a Brønsted-Lowry acid-base reaction where $H_2O$ acts as a Lewis base.
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51#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  When powdered calcium oxide is added to dilute hy 6gz:* jxq6mwdv1odh9drochloric acid in a conical flask, the products are water, positive calcium ions andd*6w6zodjv :m q1 xgh9 negative chloride ions.



Which species is the conjugate base of hydrochloric acid in this reaction?

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52#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A bottle contains dilute ethanoic x lf 8k1pz;(ah4bs2tuacid $CH_3COOH$ of unknown concentration. To determine the concentration of the acid, a student titrates the acid against a standard solution of KOH according to the following equation:
$CH_3COOH(aq) +KOH(aq) \rightarrow CH_3COOK(aq) + H_2O(I)$
1.Calculate the mass of KOH that must be used to prepare $400.0\,cm^3$ of a $0.100\,mol\,dm^{-3}\,KOH$ solution.n=  mol , m=  g
2.Calculate the pH of the $0.100\,mol\,dm^{-3}\,KOH$ solution given that it ionizes completely in solution as shown in the following equation: $KOH(aq) \rightarrow K^+(aq) + OH^-(aq)$ pH=  
3.During the titration, the student finds that exactly $20.0\,cm^3$ of the KOH solution neutralizes exactly $25.0\,cm^3$ of the $CH_3COOH$ solution. Calculate the concentration of the $CH_3COOH$ solution.C=  $mol\,dm^{-3}$

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53#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Hydrogen sulfide,$H_2S$, is a weak acid with a $pK_a$ of 7.04.
1.1.State the acid dissociation constant expression for $H_2S$.
2.Calculate $K_a$ for $H_2S$.  $\times 10^{-8}$
2.1.State the base dissociation constant expression for $HS^-$.
2.Calculate $K_b$ for $HS^-$ assuming a temperature of 298K.  $\times 10^{-7}$
3.Using your answers to parts (a)(i) and (b)(i), derive the equation $K_w =K_a \times K_b$

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54#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which quantities are required to calculate the pH of a solution of a monoprotic-ktl)g t rh:d- weak acid?-hltrtk: )-g d
I.The $pK_a$ of the weak acid
II.The concentration of the solution
III.The value of $K_w$

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55#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
1.State the complete balanced equation fo52 zeg,cnd/jdr the reaction between sulphuric acid and copper5/d ce ,djn2zg (II) oxide.
2.State the complete balanced equation for the reaction between ethanoic acid and potassium carbonate.
3.Outline two ways to monitor the rate of reaction for reaction (b) above.
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56#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Acids and bases can be classified as strong or we 4q)q3h6xiwsf ak.
1.Explain why ammonia,$NH_3$ in an aqueous solution, acts as a weak base, using an equation.
2.An experiment was carried out to determine the energy change during the following reaction:
$2NH_3(aq) + H_2SO_4(aq) \rightarrow (NH_4)_2SO_4(aq)$
Initial temperature of each solution =$21.4^{\circ}C$
Final temperature of the mixture = $23.8^{\circ}C$
1.State with a reason whether the sign of the enthalpy change for this reaction is positive or negative.
2.Suggest with a reason whether the magnitude of the enthalpy change will be    if aqueous ammonia is replaced with potassium hydroxide.


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57#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
The Brønsted-Lowry and the Lewis theories are two different theories of clasjde21r-5wujvt1h4 p qsifying acids 2jj4h p1wqu1ved-5 t rand bases.
1. 1.Distinguish between the Brønsted-Lowry theory and the Lewis theory.
2.Define incomplete octet.
Consider the dimerization of $AlCl_3$:
$2AlCl \rightarrow 3Al_2Cl_6$
2. 1.Draw structural formulas to represent this reaction.
2.Explain how this is an acid-base reaction under the Lewis theory but not the Brønsted-Lowry theory.
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58#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The pH of a $0.1\,mol\,dm^{-3}$ solution of phenol is 5.0. What is the approximate $K_a$ of phenol?

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59#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A student reacts a $15\,cm^3$ sample of $0.10\,mol\,dm^{-3}$ methylamine,$CH_3NH_2(K_b = 4.47\times 10^{-4})$,with $10\,cm^3$ of $0.10\,mol\,dm^{-3}\,HNO_3$.
1. 1.Calculate the initial number of moles of methylamine in the sample.$n(CH_3NH_2)_{initial}$ =   $\times 10^{-3}$
2.Calculate the final number of moles of methylamine after the neutralization reaction.
2.Calculate the pOH of the final solution.pOH=  

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60#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
Aqueous ammonia solutions arexm*1oazk hb20r5nnq6 commonly used to clean in houses, particularly glass such as windows. There are many safetxo2amh61nzn5q0* k r by warnings on these products.
1.Ammonia mixed in water forms ammonium hydroxide. State the equation for this process.
2.One concern is that ammonia solutions could mix with acidic cleaning products, such as drain cleaner with sulphuric acid.
1.Determine the balanced equation for ammonium hydroxide reacting with sulphuric acid.
2.Suggest a reason this reaction could be dangerous.
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61#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The function of the acid-base indicator, js3l/y p40h4y*wrh meIn, can be expressed using the equation belol/hp3y 0*msj ehyr44w w
$In + H_2O \rightleftharpoons InH^+ + OH^-;K_c = 35
Blue Yellow
Which of the below statements are correct?
I.The solution becomes darker blue with the addition of an acid
II.The solution is a pale green at equilibrium
III.$K_c$ increases with the addition of an alkali

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62#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
In the amino acid glycine, a hydrogen ion may be transferred from on) q :gkvb ;i.eo/(nibte part of the mo otkv:i)i;qnbg(./ b elecule to another as shown.



In this reaction, glycine acts as both a Brønsted-Lowry acid and a Brønsted-Lowry base.
1.State the part of the glycine molecule that acts as a Brønsted-Lowry acid in the forward reaction, giving a reason for your answer.
2.In an aqueous solution of glycine, the transfer of the hydrogen ion may involve two reaction steps. The first reaction step is shown.


(i)By considering how a hydrogen ion forms from a hydrogen atom, explain why the hydrogen ion is often referred to as a proton.
(ii)Explain why $H^+$ is not an accurate representation of the cation formed in this reaction.
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.
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63#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which of the following is a colfv : 5s9:vy*mcfa ;dcnjugate acid-base pair?


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