All Free Biology MCQs with Answers
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19844 questions · page 507 of 1985
5061. Which of the following is present in shaving soap?
- A. Sodium propionate + Gum + Glycemle
- B. Sodium palmitate + Glycerine
- C. Sodium potassium stearate + Gum + Glycerine
- D. Sodium stearate + Wax + Glycerine
Explanation: To produce stable, slick and soft lather some other ingredients like Gum and Glycerine is added with regular soap like Sodium potassium stearate.
Correct answer: Sodium potassium stearate + Gum + Glycerine5062. Which of the following catalysts is used in the modern method of preparation of soap by hydrolysis of fat using steam?
- A. SO2Cl
- B. CaCl2
- C. ZnO
- D. Conc. H2SO4
Explanation: In the preparation of soap by hydrolysis of fat using steam in presence of catalyst ZnO, the ester linkage bond breaks into glycerol and soap.
Correct answer: ZnO5063. Triacylglycerol cannot be associated with the following class of compounds:
- A. Triglyceride
- B. Oil and fat
- C. Soap
- D. Ester
Explanation: Soaps are Sodium Potassium salts of Carboxylic acids not Triacylglycerol.
Correct answer: Soap5064. Which of the following componds is insoluble in water?
- A. Calcium salt of stearic acid
- B. Calcium salt of heptadecanesulphonic acid
- C. Magnesium salt of laurylsulphonic acid
- D. Potassium salt of palmitic acid
Explanation: Calcium stearate which is also known as soap scum is insoluble in water. Due to the formation of Calcium and magnesium stearate in hard water, soap does not dissolve in hard water.
Correct answer: Calcium salt of stearic acid5065. What is the type of particle formed after the contact of sodium stearate molecules with grease particle?
- A. Neutral
- B. Negatively charged
- C. Positively charged
- D. Positively charged from inside and negatively charged from outside
Explanation: When sodium stearate comes in contact with grease particles, micelles are formed. These are negatively charged particles with hydrophillic heads and hydrophobic tails.
Correct answer: Negatively charged5066. Which of the following substaces is not used as a sedative medicine?
- A. Oxalyl urea
- B. Diazepam
- C. Veronal
- D. Eszopiclone
Explanation: Veronal is the trade name for a barbiturate drug and is used to induce sleep by suppressing the brain. Eszopiclone and diazepam are used to treat anxiety by inducing sleep. Due to the high solubility of Oxalyl urea, it is used as fertilizer.
Correct answer: Oxalyl urea5067. Synthetic pheromones, which attract male gypsy moth are esters of which of the following acids?
- A. Acetic acid
- B. Hexanoic acid
- C. Decanoic acid
- D. Dodecanoic acid
Explanation: (Z)-7,8-epoxy-2-methyloctadecane is the synthetic pheromones, which attract male gypsy moth.
Correct answer: Acetic acid5068. Naturally occurring toxin of which oil protects it from insect by giving it yellow colour?
- A. Cotton seed oil
- B. Pea oil
- C. Coconut oil
- D. All of these
Explanation: Cottonseeds contains about 15 - 20 percent oil. Its naturally occurring gossypol toxin protects it from insect by changing its giving it yellow colour.
Correct answer: Cotton seed oil5069. Which of the following compounds is used in the synthesis of a parent compound of tranquillizers and sedative medicines by condensation with urea?
- A. Barbituric acid
- B. Barbital
- C. Malonic ester
- D. Parabanic acid
Explanation: Malonic ester is used in the synthesis of barbiturates, which are a class of sedative and tranquilizer medications. This synthesis involves condensation with urea to form various barbiturates.
Correct answer: Malonic ester5070. Terpeniol and chloroxylenol are the compounds of which of the following classes?
- A. Disinfectant
- B. Chemosterilant
- C. Tranquillisers
- D. Plant growth hannones
Explanation: Terpeniol and chloroxylenol are the compounds of disinfectant class that inactivate or destroy microorganisms. Chloroxylenol and terpineol mixture is also known as Dettol.
Correct answer: Disinfectant