Tag: chemistry

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Multiple choice distinguish between black copper oxide and black manganese dioxide practical work chemistry

Write the ionic equation for reaction between manganese dioxide and hydrochloric acid.

  1. $MnO _2(s)+ 2Cl^{-}(aq) \rightarrow Mn^{2+}(aq) + Cl _2(g) + 2H _2O(l)$
  2. $MnO _2{(s)} + 4H^{+}{(aq)} + 2Cl^{-}{(aq)} \rightarrow Mn^{2+}{(aq)} + Cl _2{(g)} + 2H _2O{(l)}$
  3. $MnO _2{(s)} + 3H^{+}{(aq)} + 2Cl^{-}{(aq)} \rightarrow Mn^{2+}{(aq)} + Cl _2{(g)} + 2H _2O{(l)}$
  4. $MnO _2{(s)} + 4H^{+}{(aq)} + 2Cl^{-}{(aq)} \rightarrow Mn^{2+}{(aq)} + Cl{(g)} + 2H _2O({l})$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

$MnO _2{(s)} + 4H^{+}{(aq)} + 2Cl^{-}{(aq)} \rightarrow Mn^{2+}{(aq)} + Cl _2{(g)} + 2H _2O{(l)}$

Multiple choice chemistry the periodic table periodic trends in chemical properties alkali metals study of specific groups

Which of the following exists as an individual gas-phase atom under standard conditions?

  1. $\displaystyle C$
  2. $\displaystyle N$
  3. $\displaystyle O$
  4. $\displaystyle F$
  5. $\displaystyle Ne$
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Option E is the correct answer.

${Ne} $ or Neon is an inert gas. It has a complete octet (2,8) with 8 electrons in its outermost orbit and is highly stable. And thus under standard conditions it remains as an individual gas phase atom without forming a molecule. 

Multiple choice chemistry the periodic table periodic trends in chemical properties alkali metals study of specific groups

Group contains the noble gases is_______ group.

  1. 16th

  2. 17th

  3. 18th

  4. Both B and C
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Group 18 contains noble gases.


They have already stable and octet configuration that is they contain 8 electrons in their outer most shell.

Hence they have high ionization potential and zero electron affinity.

They do not participate in chemical bonding because already they are stable.

Option C is correct.

Multiple choice chemistry the periodic table periodic trends in chemical properties alkali metals study of specific groups

Inert gases are otherwise called zero valent elements.
State whether the given statement is true or false.

  1. True

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

Given statement is true.
In general noble elements have a stable configuration that is octet configuration with all orbitals filled. Hence no tendency in either accepting or donating electrons. This is why those are called zero valent elements. 

Multiple choice chemistry the periodic table periodic trends in chemical properties alkali metals study of specific groups

Why noble gases are generally non-reactive?

  1. Because they are classified as zero group elements

  2. Because they are in gaseous state

  3. Due to their stable electronic configuration

  4. Because they are p-block elements
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Noble gases are chemically inert because they have a stable, complete valence electron shell (octet configuration), making them highly unlikely to gain, lose, or share electrons.