Science Chemistry Questions: Atom & Redox (Video Solutions)

In the recent series by Achieversdream, our tutors explain how to solve some of the questions from the MCQ sessions. Attempt the following questions and head to the youtube link attached for the solutions! 

Atoms

1. Which particle has the most number of electrons? 

1. A sodium ion 
2. A molecule of hydrogen chloride 
3. A molecule of water
4. An oxide ion 

Solution: Q1

2. In which compound does one of the atoms not achieve the electronic configuration of 2.8?

1. NACL
2. Al₂O₃
3. MGO
4. NA₂O

Solution: Q12 

Redox

3. The reaction between bromide ions and bromate(V) ions is represented by the following equation: 

5Br^– + BrO₃^– + 6H⁺ > 3Br₂ + 3h₂O

Which of the following statements is/are false? 

1. Hydrogen ions are reduced to water
2. The bromate(V) ion has undergone reduction 
3. The bromide ion is the oxidising agent 
4. The oxidation number of bromine in bromate(V) ions is +5 

1. 1 only 
2. 1 and 4 only 
3. 1 and 3 only 
4. 1,2, and 3 only. 

Solution: Q27

4. Separate samples of an unknown solution X are added to aqueous potassium iodide and acidified potassium manganate (VII).

It is observed that aqueous potassium iodide turns from colourless to brown and acidified potassium manganate(VII) remains purple. 

What conclusion about X is correct? 

1. X is only a reducing agent 
2. X is only and oxidising agent 
3. X is both an oxidising agent and a reducing agent 
4. X is neither an oxidising agent or a reduction agent
   

Solution Q16