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Multiple choice chemistry p- block elements-ii hydrogen chloride chlorine - 17 group p-block elements

The $pK _{a}$ of oxoacids of chlorine in water follows the order:

  1. $HClO < HClO _{3} < HClO _{2} < HClO _{4}$
  2. $HClO _{4} < HClO _{3} < HClO _{2} < HClO$
  3. $HClO _{4} < HClO _{2} < HClO _{3} < HClO$
  4. $HClO _{2} < HClO < HClO _{3} < HClO _{4}$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The higher the oxidation number of chlorine, higher is the acidic strength of the oxoacid of chlorine. $HClO _4$ has the highest number of oxygen atoms, hence the oxidation number of chlorine is highest in it. Therefore, it is the most acidic. Therefore, it has the smallest value of $pK _\alpha$. Similarly, the oxidation number of chlorine in $HClO$ is the lowest because it has the least number of oxygen atoms. Hence its acidic strength is the least, and so its $pK _\alpha$ is the highest.

Multiple choice chemistry p- block elements-ii hydrogen chloride chlorine - 17 group p-block elements

$HCl$ is soluble in organic solvents such as benzene and toluene.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

HCl is a covalent compound which dissociates to form hydrogen and chloride ions. Benzene and toluene undergo electrophilic aromatic substitution reaction when chloride ion binds to the benzene ring forming aryl halides.

Multiple choice chemistry p- block elements-ii hydrogen chloride chlorine - 17 group p-block elements

Which of the following is a good conductor of electricity?

  1. Anhydrous $HCl$
  2. Aqueous $HCl$
  3. $HCl$ gas
  4. Crystalline $HCl$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Aqueous $HCl$ is ionized as $H^{+},Cl^{-}$ which allows the electricity to flow  where as all other $HCl$ is available as unionized form which do not allow the electricity to pass.
Hence option $B$ is correct.

Multiple choice chemistry p- block elements-ii hydrogen chloride chlorine - 17 group p-block elements

The metal that cannot displace hydrogen from dilute hydrochlocric acid is 

  1. aluminium

  2. iron

  3. copper

  4. zinc

  5. magnesium
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Metals below hydrogen in the reactivity series, such as copper, cannot displace hydrogen from dilute acids. Aluminium, iron, zinc, and magnesium are all more reactive than hydrogen.

Multiple choice chemistry p- block elements-ii hydrogen chloride chlorine - 17 group p-block elements

Name the ion(s) obtained when $HCl$ dissociates in aqueous solution.

  1. ${ H } _{ 3 }{ O }^{ + }$
  2. ${ Cl }^{ - }$
  3. Both $A$ and $B$

  4. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Acidic nature of $HCl$ is due to hydrogen ions which reacts with water to form hydronium ions. 
$HCl(g) +{ H } _{ 2 }O \rightleftharpoons { H } _{ 3 }{ O }^{ + }+{ Cl }^{ - }$