Tag: natural resources- air, water and land

Questions Related to natural resources- air, water and land

Multiple choice chemistry nitrogen and sulfur sulfur and its oxides acid deposition natural resources- air, water and land
High concentration of $SO _2$ leads to stiffness of flower buds.
  1. True

  2. False

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

$SO _2$ is particularly poisonous to trees causing chlorosis and dwarfing. High concentration of $SO _2$ leads to stiffness of flower buds which then eventually fall off. Sulphur oxides $(SO _x)$ and sulphuric acid $(H _2SO _4)$ are related with the damage and destruction of vegetation, soil deterioration, construction material and watercourses.

Multiple choice chemistry nitrogen and sulfur sulfur and its oxides acid deposition natural resources- air, water and land

Select the correct statement (S).

  1. p- chlorometaxylenol and dichlorometaxylenol are antibacterials and deodorants

  2. BHT and BHA are food antioxidants

  3. $SO _2$ and $SO _3^{-2}$ are antioxidants for wine and beers
  4. All of the above are correct statements

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
(A) p-chlorometaxylenol & dichlorometaxylenol are antibacterials & deodrants as they are most effective against gram positive bacteris.
(B) BHA & BHT are antioxidants as oxygen reacts preferentially with BHA or BHT rather than oxidising fats or oils thereby protecting them from spoilage.
(C) $SO _{2} $ & $ SO _{3}^{2-}$ are used as preservative because of antioxidative & antimicrobial properties.
Multiple choice chemistry nitrogen and sulfur sulfur and its oxides acid deposition natural resources- air, water and land

Which of the following acts as pickling agent?

  1. $\displaystyle\;HNO _3$
  2. $\displaystyle\;HCl$
  3. $\displaystyle\;H _2SO _4$
  4. $\displaystyle\;HNO _2$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Pickling is a metal surface treatment i.e; used to remove impurities such as strains, inorganic contaminants on the surface of the metal. So to remove this pickling liquor containing acid is used. 

$H _2SO _4$ is used as pickling agent because of its high oxidizing power, for which it can dissolve noble metals as well.

Multiple choice chemistry nitrogen and sulfur sulfur and its oxides acid deposition natural resources- air, water and land

$1000L$ of air at STP was dissolved in water and required $2.5\times { 10 }^{ -5 }$ moles of $KMn{ O } _{ 4 }$ for complete reaction of ${SO} _{2}$ at pollutants. Thus, ${SO} _{2}$ content in air is :

  1. $1.4ppm$
  2. $14ppm$
  3. $2.8ppm$
  4. $6.25ppm$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Reaction: 5SO2 + 2MnO4- + 2H2O -> 5SO4(2-) + 2Mn(2+) + 4H+. 2 moles of MnO4- react with 5 moles of SO2. 2.5*10^-5 moles of KMnO4 react with (5/2)*2.5*10^-5 = 6.25*10^-5 moles of SO2. Volume of air = 1000 L. Moles of SO2 per L = 6.25*10^-8. At STP, 1 mole = 22.4 L. Concentration in ppm = (Volume SO2 / Volume air) * 10^6 = (6.25*10^-5 * 22.4 / 1000) * 10^6 = 1.4 ppm.

Multiple choice chemistry nitrogen and sulfur sulfur and its oxides acid deposition natural resources- air, water and land

A solution of chromium oxide in concentrated sulphuric acid is used for cleaning glass in laboratories because it:

  1. Removes sand particles

  2. Oxidises grease

  3. Dissolves glass

  4. Reacts with dust

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Because a solution of chromium oxide in sulfuric acid (also known as a sulfochromic mixture or chromosulfuric acid) is a powerful oxidizing agent, it can be used to clean laboratory glassware, particularly of otherwise insoluble organic residues.They oxidize the grease present on the glass surfaces and hence thus it can be cleaned.