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Volume of the solution = 250mL = 0.25L

Let the no. of moles of solute be n

Molarity = No. of moles of solute/volume of solution

⇒ 0.15 = n/0.25

⇒ n = 0.0375moles

Molar mass of C₆H₅OH = 6×12 + 5×1 + 16 + 1 = 94g

Moles = mass/molar mass

⇒ 0.0375 = m/94

Mass of benzoic acid required = 3.525g.

16.17

Phenol is one such particular substance that can act both as an antiseptic as well as a disinfectant depending upon the concentration of the solution used. An antiseptic is used to prevent the growth of germs in cuts and wounds.

For instance, a phenol of 0.2% concentration acts as antiseptic and phenol of concentration 1% acts as a disinfectant.

16.16 

Magnesium or Aluminium hydroxides do not tackle with the root cause of acidity that is they reduce the acidity by reacting with excess acid present in the stomach [neutralization reaction].

On the other hand cimetidine and ranitidine relieve acidity by preventing interaction of histamine with receptors of stomach walls and hence release of excess acid by stomach walls is stopped. So the root cause of acidity is totally eliminated.

Therefore cimetidine and ranitidine relieve the acidity by tackling the root cause whereas magnesium or aluminum hydroxide just relieves by healing only the mere cause of acidity.

Total mass of solution = 6.5g + 450g = 456.5g

Therefore mass percentage of aspirin in solution = (mass of aspirine/total mass of solution) = 6.5/456.5

⇒ mass % of aspirine = 1.424%

16.15 

Antiseptics and disinfectants are effective against micro-organisms. Antiseptics are applied to the living tissues such as wounds, cuts, ulcers, and diseased skin surfaces, while disinfectants are applied only to inanimate objects such as floors, drainage system, instruments, etc. Disinfectants are harmful to the living tissues. Iodine is an example of a strong antiseptic. Tincture of iodine (2 − 3 percent of solution of iodine in alcohol − water mixture) is applied to wounds. 1 percent solution of phenol is used as a disinfectant.

The Solubility product of CuS (ksp) = 6 × 10^-16

CuS → Cu ⁺⁺ + S^2-

Let the s be solubility of CuS in mol/L

Ksp = [ Cu ⁺⁺ ] [S²]

Ksp = solubility product

6 × 10^-16 = s × s = s²

⇒ S = 2.45 × 10^-8 mol/L

Hence, the maximum molarity of CuS in an aqueous solution is 2.45 × 10^-8 mol/L

16.14 

Antibiotics that are effective against a wide range of gram-positive and gram-negative bacteria are known as broad spectrum antibiotics. Chloramphenicol is an example of a broad spectrum antibiotic. It has the following structure: -

It can be used for the treatment of typhoid, dysentery, acute fever, pneumonia, meningitis, and certain forms of urinary infections. Two other examples of broad spectrum antibiotics are vancomycin and ofloxacin. Ampicillin and amoxicillin? synthetically modified from penicillin are also broad spectrum antibiotics.

Mass of ions = 92g

Molar mass of ions = Na⁺ = 23g (neglect the mass lost due to absence of a electron)

Moles of ions = mass of ions/molar mass

⇒ n = 92/23 moles

⇒ n = 4moles

Molality of solution = moles of solute/mass of solvent (in kg) Molality = 4/1 = 4M

It is mandatory to save choices during the NEET SS counselling. If candidate does not lock the choice submitted, the choices saved by him/her will be automatically locked on the last date of choice locking. Also, once the choice locking deadline is over, candidates will not be allowed to modify the NEET SS counselling choices. 

16.13 

Anti-depressant drugs are needed to counteract the effect of depression. These drugs function by inhibiting the enzymes catalysing the degradation of the neurotransmitter, noradrenaline. As a result, the important neurotransmitter is slowly metabolised and then it can activate its receptor for longer periods of time.

Two anti-depressant drugs are:

(i) Iproniazid

(ii) Phenelzine

Now n-octane is non-polar solvent due to long chain saturated structure. We know that “like dissolves like” so a non-polar compound will be more soluble in non-polar solvent as compared to polar compound.

So cyclohexane is non-polar due to symmetric structure. KCl is ionic in nature as it will dissociate into K ⁺ and Cl^- ions. CH₃CN is polar as mentioned above and CH₃OH is also polar in nature.

The order of increasing polarity is:

Cyclohexane < CH₃CN < CH₃OH < KCl (O is more electronegative than N)

Therefore, the order of increasing solubility is:

KCl < CH₃OH < CH₃CN < Cyclohexane

No, CIMAGE College admissions are primarily entrance-based. The college admits candidates based on a college-level Entrance-cum-Scholarship test. Those who clear the test are then further called in for personal interview. Those who clear both selection rounds in addition to fulfilling the eligibility are offered seats. However, students may visit the college's help desk to get more information about the admission chances.

16.12

Specific drugs affect only some specific or particular receptors. Antacids and anti-allergic drugs work on different receptors. This is the reason why antacids and anti-allergic drugs do not interfere with each other's functions, but interfere with the functions of histamines.