Explore topic-wise InterviewSolutions in Current Affairs.

सिद्धेश्वरी का परिवार घोर आर्थिक संकट से गुजर रहा है। घर में खाने के लाले पड़े हुए हैं। किसी को भी भरपेट भोजन नसीब नहीं है। इसके बावजूद सिद्धेश्वरी हिम्मत नहीं हारती है। वह घर की आर्थिक स्थिति का जिक्र कर किसी को दुःखी नहीं करना चाहती। वह अपने बच्चों व पति की हिम्मत बढ़ाती है। स्वयं कम खाकर बाकी परिवार को भोजन कराना अपना कर्तव्य समझती है। सिद्धेश्वरी जीवटता, त्याग और साहस की प्रतिमूर्ति है।

रामचंद्र मुंशी चंद्रिका प्रसाद और सिद्धेश्वरी का बड़ा लड़का है। उसके बाल अस्त-व्यस्त है, मुँह लाल है। उसके फटे-पुराने जूतों पर गर्द जमी हुई है। उसकी उम्र करीब 21 वर्ष है। दुबलापतला, लंबा, गोरा रंग, बड़ी-बड़ी आँखें व ओंठों पर झुरियाँ। वह एक स्थानीय समाचार-पत्र के ऑफिस में प्रूफरीडरी का काम सीखता है। इंटर पास किया है।

सिद्धेश्वरी के मँझले लड़के का नाम मोहन था।

सिद्धेश्वरी के छोटे बेटे का नाम प्रमोद था।

सिद्धेश्वरी के छोटे लड़के की उम्र छः साल थी।

मुंशी चंद्रिका प्रसाद लगभग पचास-पचपन साल के लगते थे।

मोहन हाईस्कूल का प्राइवेट इम्तहान देने की तैयारी कर रहा था।

The particles of the suspension scatter a beam of light which is passing through it and make its path visible.

Ornamental gold is an alloy of gold and copper in which the components of mixture is uniform and not visible with a naked eye.

(a) Silver

(b) Copper

(c) Silver sulphide

(d) Basic copper carbonate

(e) Dilute acid solution; The acid sol ution dissolves green coloured basic copper carbonate present on the corroded copper object makes it look shiny, red brown again.

In gases the particles are not fixed to a position and are more free to move in the space available to them. Hence they do not have definite shape and volume.

(iii) Impurity defect has no effect on the density of the substance.

(iv) Frankel defect results in an increase in the density of the substance.

(ii) Quartz glass (SiO₂)

Number of protons : 8, Number of neutrons : 10.

Atomic mass = Number of + Number of number (A) protons (p) neutrons (n)

(a) Due to absence of d- orbital,nitrogen cannot ex-pand its valency beyond there.

(b) Because of pπ- pπ multiple bonding in dioxy-gen which is absent in sulphur.Due to small size and high elctrogegativity oxygen acts as diatomic molecular held by weak van der waals' forces S Because of big siz and lower electonegativity form S-S single bonds.

(c) Due to excitation of electron by absorption  of rediation from visible region.

The particle of an atom that has no charge is neutrons.

Electron is a negatively charged particle found in the atoms of all elements. 

The relative mass of an electron is 1/1840 u. 

A charge of -1 is carried by an electron.

➢ There is some force of attraction between the particles of the matter which bind them together. This force of attraction between the particles of same substance is known as force of attraction (or cohesion).

➢ In general, the force of attraction is maximum in the particles of solid matter and minimum in the particles of gaseous matter.

Correct option is (a) 18

(i) Same in all directions

Isotopes of Cobalt-60 are used in the treatment of cancer.

The atomic number of carbon is 6 and the atomic mass number is 12.

The atomic mass number of chlorine is 35.

Correct option is (C) oxygen

According to Bohr-Bury scheme, the maximum number of electrons which can
be accommodated in a given shell is given by the formula 2n².

Hence, the correct option is A.

Protons and neutrons actually determine the mass of atom.

The crystalline borax has formula

Na₂B₄O_{7 .}10H₂O or Na₂ [B₄O₅ (OH)₄].8H₂O.

Quartz, cristobalite and tridymite are the different crystalline forms of silica.

[Note: These crystalline forms are interconvertible at a suitable temperature.]

(i) Substance X is lime water.

Ca(OH)₂ + CO₂ → CaCO₃ + H₂O

Ca(OH)₂  -(Lime water)

CO₂   -(Carbon dioxide)

CaCO₃ -(Calcium carbonate)

H₂O - (Water)

(ii) Calcium oxide reacts vigorously with water to produce slaked lime (calcium hydroxide) releasing a large amount of heat.

CaO(s) + H₂O(l)→ Ca(OH)₂(ag)

CaO(s) - (Quicklime)

Ca(OH)₂(ag) - (slaked lime)

Option : c. H-3

(i) Substance X- Calcium Hydroxide.

Ca(OH)₂(aq) + CO₂(g)  → CaCO₃(s) H₂O

(ii) Calcium hydroxide is obtained by reaction of calcium oxide and water.

CaO(s) + H₂O(l) → Ca(OH)₂(aq) + Heat 

Option : a. Rb

On mixing the clear solution of two ionic compounds, as a substance which is insoluble in water, is formed. This insoluble substance is known as a formed is called precipitation reaction.

Example: When sodium sulphate solution is mixed with barium chloride solution, a white precipitate of a substance (BaSO₄) is formed.

Na₂SO₄(aq) +BaCl₂(aq) → BaSO₄↓ +2NaCl(aq)

A balanced equation is the one in which number of different atoms on both the reactant and product sides are equal. Balancing chemical equation is necessary for the reaction should obey The Law of Conservation of energy. Balancing the chemical equation has no defined method and is purely a trial and error attempt.

(i) Exothermic Reaction

CaO + H₂O → Ca(OH)₂

(ii) Double displacement reaction.

BaCl₂+Na₂SO₄ → BaSO₄+2NaCl

The Reaction in which an insoluble Substance or precipitate is formed called precipitation reaction.

Example:

Na₂SO₄+BaCl₂ → 2NaCl+BaSO₄↓

When quicklime (calcium oxide- CaO) is added to water, it reacts vigorously with water to produce slaked lime (calcium hydroxide) and releases a large amount of heat.

The reaction that takes place is:

CaO + H₂O → Ca(OH)₂

Quick lime Slaked lime

The above reaction is an example of combination reaction in which calcium oxide and water combined together to form a single product, calcium hydroxide.

When HCl is diluted with copper oxide, the following reaction takes place:

HCl + CuO → CuCl₂ + H₂O

The new compound formed is copper chloride (CuCl₂) which imparts a bluegreen colour to the solution. The above reaction is a type of double displacement reaction.

ZnO + C 

(i) Zinc oxide. 

(ii) Carbon.

C) Spoilage of food by oxidation

C) Addition of aqueous Na₂SO₄ to aqueous BaCl₂ forms clear solution. 

a) \(N_2(_g) + 3H_2\overset {Catalyst}\rightarrow2NH_3\)

Combination  reaction 

b)  NaOH(aq) + CH₃COOH(aq) → CH₃COONa(aq) + H₂O(l) 

Double displacement reaction/Neutralisation reaction

c) \(C_2H_5OH(_l) + CH_3COOH(_l)\overset {H^+}\rightarrow CH_3COOC_2H_5(_l)+H_2O(_l)\)

 Double displacement reaction/Esterificaton reaction 

d)  C₂H₄(g) + 3O₂(g) → 2CO₂(g) + 2H₂O(g) + Heat + Light  

Redox reaction/Combustion reaction

B) 1 – d, 2 – b, 3 – a, 4 – c

When oil or fat or left over cooking oil for making food stuff undergoes oxidation ir stored for a long time and it is found to have foul odour called rancidity.

3BaCl₂(aq) + Al₂(SO₄)₃(aq) ➝ Al₂Cl₃(aq) + 3BaSO₄(s)

3BaCl₂ (aq) + Al₂ (SO₄)₃ (aq) —–> 3BaSO₄ (s) + 2AlCl₃ (aq)

(a) 2NaOH + H₂SO₄ —–> Na₂SO₄ + 2H₂O 

(b) Ca(OH)₂ + CO₂ —–> CaCO₃ + H₂O