Explore topic-wise InterviewSolutions in .

(C) acetic anhydride

CH₃COONa (Sodium acetate ) + CH₃COCl (Ethanoyl Acetic) → (CH₃–CO)₂O (anhydride chloride)+ NaCl 

(i) CH₃CHO gives brick red ppt. with Fehling, C₆H₅CHO not.
(ii) Phenol does not give brisk effervescence but CH₃COOH gives this test with NaHCO₃.
(iii) Pentanal forms silver mirror but pentan-2-one does not.

 Ostwald’s process (Large scale preparation): Ostwald’s process is used to prepare nitric acid on a large scale. 

a. This method is based upon catalytic oxidation of NH₃ by atmospheric oxygen. 

4NH_3(g) (Ammonia) + 5O_2(g) (From air) \(\underset{500K,9bar }{\stackrel{Pt/Rh gaugecatalyst}{\longrightarrow}}\) 4NO_(g) (Nitric oxide) + 6H₂O_(g)  

b. Nitric oxide reacts with oxygen to form nitrogen dioxide

2NO_(g) (Nitric oxide) + O_2(g) (Oxygen) ⇌ 2NO_2(g) (Nitrogen dioxide)

c. Nitrogen dioxide on dissolution in water gives nitric acid.

3NO_2(g) (Nitrogen dioxide) + H₂O_(l) (Water )→ 2HNO_3(l) (Water ) + NO_(g) 

The nitric oxide (NO) thus formed is recycled and the aqueous HNO₃ is concentrated by distillation to give 68% HNO₃ by mass. Further, concentration to 98% can be achieved by dehydration with concentrated H₂SO₄.

1. Naphthalene, camphor and benzoic acid when heated, pass directly from solid to vapour without melting. On cooling the vapours will give back solid. This phenomenon is known as sublimation. This technique is used to purify naphthalene, camphor from non volatile impurities.

2. Substances to be purified is taken in a beaker. It is covered with a watch glass. The beaker is heated for a while and the resulting vapours condense on the bottom of the watch glass. Then the watch glass is removed and the crystals are collected.

(I) Chloroform is slowly oxidised by air in the presence of light to an extremely poisonous gas, carboxyl chloride (phosgene), it is therefore stored in closed dark coloured bottles completely filled so that air is kept out.

(II) With the use of 1 % ethanol we can stabilise chloroform, because ethanol can convert the poisonous COCl₂ gas into non poisonous diethyl carbonate.

COCl₂ + 2C₂H₅OH → CO(OC₂H₅)₂ + 2HCl.

(I) Carius method

• Procedure: A known mass of the organic compound is taken in a clean carius tube and few mL of fuming HNO₃ is added and then the tube is sealed. It is then placed in an iron tube and heated for 5 hours. The tube is allowed to cool and a hole is made to allow gases to escape. 
• The carius tube is broken and the content collected in a beaker. Excess of BaCl₂ is added to the beaker. H₂SO₄ formed is converted to BaSO₄ (white ppt.) The precipitate is filtered, washed, dried and weight. From the mass of BaSO₄ , percentage of S is calculated.

(II) Calculation: 

Mass of organic compound = Wg 

233 g of BaSO₄ contains 32 g of sulphur 

Percentage of sulphur =\((\frac{32}{233} \times \frac{x}{ω} \times 100)\)%

(II) Distillation is used in case of volatile liquid mixed with a non-volatile impurities. 

Distillation under reduced pressure: 

This method is used to purify such liquids which have very high boiling points and which decompose at or below their boiling points. Steam distillation is used to purify steam volatile liquids associated with water immiscible impurities.

pOH is 14-9 = 5.

So OH^- = 10^-5 

% dissocaition is = 0.01%.

The IUPAC name of K₄[Fe(CN)₆ ] is Potassium hexa cyano ferrate (II) .

AgNO₃ Solution copper displace the metal .

In liquids the molecules are less free than in gas i.e. intermolecular forces in liquid are greater than in gas.

3y/2 + y+4/4 = 5 - (y-2)/4

6y + y/4 + 4 = \(\frac{20-y+2}4\)

7y + 4 = 20 - y + 2

7y + y = 22 - 4

8y = 18

y = 18/8 = 9/4

∴ y = 9/4.

(b) Noninverting amplifier

(a) AC load line

(c) Equals output power divided by input power

(b) Total dc current from the supply

Correct option: b) Sand blast

a. Fear is defined as an unpleasant feeling triggered by the perception of danger, real or imagined. 

b. It is a fundamental part of human psychology. Our brains are wired to feel fear because it helps us avoid calamity; it keeps us safe. But fear can also hold us back if we let it. Fear feeds on fear, meaning the more we try to avoid something we’re afraid of, the bigger and deeper our anxiety grows. To overcome this, we must face our deep-seated misgivings and worries. We have to acknowledge our fears and find ways to move beyond them.

WATER  is the major visible constituent of the exhaust plume from a natural gas-fired power plant.

Correct option: a. In between clutch and propeller shaft

Correct option: d) Spark plug

a. This problem has come a long way and the probable solution to this has been provided in 4Rs of sustainable development – REFUSE, REDUCE, REUSE & RECYCLE. 

b. Following these has definitely helped minimize the waste and pollution. But, the recyclers’ job at its best is trying to put a full stop to this problem. The concept of upcycling and the avenues it has created for a green market are luring and helps resolve this problem to a great extent.

Correct option: c. both a and b.

You use a hydrometer to check the condition of the electrolyte in your car battery. It is actually measuring  DENSITY property of the fluild.