Tag: biological oxidation

Quizzes (3) Questions (149)

Questions Related to biological oxidation

Multiple choice bio-chemistry biological oxidation classical idea of redox reactions oxidation reduction redox reaction

When a piece of magnesium ribbon is placed in a beaker of copper sulfate solution, which one of the following is most likely to happen?

  1. A vigorous reaction immediately takes place, with the release of a lot of heat.

  2. The blue colour of the copper sulfate solution gets darker.

  3. The blue colour of the copper sulfate solution gets lighter.

  4. The magnesium catches fire.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

$Mg+CuSO _4 \longrightarrow MgSO _4 + Cu$

            $(Blue)$
By adding$Magnesium$ to $CuSO _4$, it turns to $MgSO _4.$
Because $Mg$ is above $Cu$ in reactivity series. So $Mg$ displaces $Cu$ in $CuSO _4$. As reaction processes, $CuSO _4$ content decreases.
$\therefore$ Color blue fades. 

Multiple choice bio-chemistry biological oxidation classical idea of redox reactions oxidation reduction redox reaction

In the electrochemical series, metals are arranged in order of their tendency to :

  1. release halogens from their salts

  2. become reduced

  3. react with water

  4. lose electrons
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In the electrochemical series, metals are arrange in order of their tendency to lose electrons. 

$\bullet$ Oxidation potential increases down the group.(tendency to lose electron increases).
$\bullet$ Reduction potentials decreases down the group. (tendency to gain $e^-$ decreases).

Multiple choice bio-chemistry biological oxidation classical idea of redox reactions oxidation reduction redox reaction

Which one of the following substances is a good oxidising agent?

  1. coke

  2. water

  3. Hydrogen peroxide

  4. Sulphur dioxide
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A good oxidizing agent is one which can readily oxidize other chemical species and reduce itself. Therefore, the compound which is good oxidizing agent must have initial oxidation as high, so that it can reduce its oxidation state and get reduced and oxidize others.

$Coke:$ Reducing agent 
$Hydrogen$ $peroxide$ $(H _2O _2):$ because oxidation state of oxygen is -1 in hydrogen peroxide. So, it oxidizes to 0 & acts as a reducing agent & it reduces to -2 & acts as an oxidizing agent. But, generally, it acts as an oxidizing agent because a stable oxidation state of oxygen is -2(oxide form)
$H _2O:$ Reducing agent.
$SO _2$: sulfur in the +4 oxidation state, sulfur dioxide is a reducing agent. It is oxidized by halogens to give the sulfuryl halides, such as sulfuryl chloride

Hence, the correct option is $\text{C}$

Multiple choice bio-chemistry biological oxidation classical idea of redox reactions oxidation reduction redox reaction

What electrolyte is used to electroplate silver onto a spoon?

  1. pure water

  2. silver nitrate

  3. copper sulfate

  4. acidified water
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

$Ans:$ $Silver$ $Nitrate.$

In silver plating, the object (eg.spood) to be plated is made the cathode of an electrolytic cell. The anode is bar of silver metal and the electrodyte must contain $Ag^+$ ions (i.e. $AgNO _3$), so that when the direct current is passed through the cell, positive ($Ag^+$) ions move towards the negative anode (spoon) where they are neutralized by $e^-$ and stick to spoon as silver metal.

Multiple choice bio-chemistry biological oxidation classical idea of redox reactions oxidation reduction redox reaction

Oxalic acid dihydrate, $H _{2}C _{2}O _{4}\cdot 2H _{2}O(s)$ is often used as a primary reagent to standardise sodium hydroxide solution. Which of these facts are reasons to choose this substance as a primary standard?
I. It is diprotic.
II. It is a stable compound that can be weighed directly in air.
III. It is available in pure form.

  1. III only

  2. I and II only

  3. II and III only

  4. I, II and III
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

$\begin{array}{l} { H _{ 2 } }{ C _{ 2 } }{ O _{ 4 } }\cdot 2{ H _{ 2 } }O\left( s \right) \to oxadic\, acid\, dihydrate\,  \ Since,\, it\, is\, very\, stable\, and\, also\, available\, in\, pressure \ from\, in\, the\, laboratory\, i.e.\, it's\, always\, used\, as\, primary\, s\tan  dard\, in\, the\, lab. \ Hence,\, the\, option\, C\, is\, the\, correct\, answer. \end{array}$

Multiple choice bio-chemistry biological oxidation classical idea of redox reactions oxidation reduction redox reaction

For the redox reaction:


          $Zn+N{ O }^- _3\rightarrow Zn^{2+}+NH^+ _4$ 

in a basic medium, coefficients of $Zn, \ NO^- _3$ and $OH^-$ in the balanced equation respectively are:

  1. $4, 1, 7$
  2. $7, 4, 1$
  3. $4, 1, 10$
  4. $1, 4, 10$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Balancing the redox reaction Zn + NO3- -> Zn2+ + NH4+ in basic medium involves balancing electrons and charge. The balanced equation is 4Zn + NO3- + 7H2O -> 4Zn2+ + NH4+ + 10OH-. Thus, the coefficients are 4, 1, and 10.

Multiple choice bio-chemistry biological oxidation classical idea of redox reactions oxidation reduction redox reaction

The mass of $H _{2}O _{2}$ that is completely oxidised by $30.2\ g$ of $KMnO _{4}$ (molar mass= $158\ g mol^{-1}$) in acidic medium is 

  1. $12\ g$
  2. $14\ g$
  3. $16\ g$
  4. $1\ g$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In acidic medium, 2 moles of KMnO4 react with 5 moles of H2O2. Calculating moles of KMnO4 (30.2g / 158g/mol = 0.191 mol), the required moles of H2O2 is (5/2) * 0.191 = 0.4775 mol. Mass = 0.4775 * 34g/mol = 16.2g, which rounds to 16g.