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System gains heat Q is positive 

System loses heat Q is negative 

Work done on the system W is negative 

Work done by the system W is positive

Correct answer is (a) W = 0

(b) ∆U = – W in an adiabatic process 

According to the first law of thermodynamics ∆Q = AU + W In an adiabatic process, ∆Q = 0. Therefore, ∆U = – W

Correct answer is (b) P, T, U

Kelvin-Planck statement: It is impossible to construct a heat engine that operates in a cycle, whose sole effect is to convert the heat completely into work. This implies that no heat engine in the universe can have 100% efficiency

Extensive variable depends on the size or mass of the system. 

Example : Volume, total mass, entropy, internal energy, heat capacity etc. 

Intensive variables do not depend on the size or mass of the system. 

Example: Temperature, pressure, specific heat capacity, density etc.

Thermodynamic system: A thermodynamic system is a finite part of the universe. It is a collection of large number of particles (atoms and molecules) specified by certain parameters called pressure (P), Volume (V) and Temperature (T). The remaining part of the universe is called surrounding. Both are separated by a boundary. 

Examples: A thermodynamic system can be liquid, solid, gas and radiation.

(a) 273.15 K

(a) increase till 4°C and then decrease. 

The density of water increases from 0° to 4°C and then decreases. Therefore, the volume V of the block above water level will increase till 4°C and then decrease.

Correct answer is (a) increase

The coefficient of linear expansion of the material of a solid rod is defined as the increase in length per unit original length per degree rise in its temperature.

The unit of a_L is°C^-1 (or KT^-1 )

According to boyle's law

(P + ΔP) (V - ΔV) = PV

(P + ΔP) (V - 0.1 V) = PV

PV + VΔP - 0.1 PV - 0.1 VΔP = PV

0.9 V ΔP = 0.1 PV

\(\frac{ΔP}{P}\) = \(\frac{1}{9}\)

Percentage increase = \(\frac{ΔP}{P}\) x 100 = \(\frac{100}{9}\) = 11.1

Percentage increase = 11.1 %

NaOH → Na⁺ + OH^- (hydoxide ion)

a) Force, distance 

b) Zero 

c) Newton, meter, force 

d) Energy, kinetic energy 

e) Mechanical

A) position, state

C) gravitational force

(c) potential energy

Explanation:- 

The potential energy of a system is due to its configuration and separation depicts the configuration.

Yes, it is possible that a force is acting on a body and still the work done is zero. 

When a man is pushing a wall, work done is zero as there is no displacement.

Mass = 200 g = 0.2kg 

Height = 5m 

Initial velocity, u = 0

Acceleration due to gravity, g = 9.8 m/s² 

Final velocity, v

Using third equation of motion, 

v² – u² = 2gs 

v² = 98 

Kinetic energy = ½ mv² 

Kinetic energy = (½)(0.2)(98) = 9.8J

(क) ऊपर बाएँ से नीचे दाएँ।  

OH

Bases and alkalies: 

All bases are not alkalies. Water-soluble bases are called alkalies. NaOH and KOH are alkalies. But even though Al(OH)₃ and Cu(OH). are based, they are not considered as alkalies as they are not soluble in water. Metallic oxides are generally basic in nature. But a few of them have both acidic as well as basic character. Such oxides are called amphoteric oxides.

Example Al,O₃ , ZnO 

They can react with acids as well as bases.

Following are the quantities on which the amount of work done depends: 

a) magnitude of the force 

b) distance through which the body moves 

Force and distance are related to work done as work done is directly proportional to the force applied and the distance moved by the body. 

W = Fs 

Where, 

W is the work done 

F is the force applied 

s is the distance travelled

Given: 

Mass (m) = 0.5 kg 

Acceleration due to gravity (g) = -9.8 m/s² 

Displacement (s) = 5 m. 

To Find: 

Work done (W) = ? 

Formula: 

W = P.E = mgh 

Solution: 

W = mgh 

= 0.5 x (-9.8) x 5 

= -24.5 J

The work done by the force of gravity is -24.5 joule.

The work done against the gravity when a body is move horizontally along a frictionless surface is zero as the force of gravity acts perpendicular to the direction of motion.

Mass of the body, m = 2kg 

Initial velocity, u = 20 m/s 

Acceleration due to gravity, g = 10 m/s² 

Height reached = h 

Time, t = 2 s 

Using second equation of motion, 

h = ut = 1/2 gt² 

h = 20m 

PE after 2 s = mgh = 400J

(a) Mg²⁺ SO₄^2- → Mg²SO₄² → Mg₂(SO₄)₂ → Mg_2/2(SO₄)_2/2 → MgSO₄

(b) Mg²⁺NO₃^1- → Mg²NO₃¹  →Mg(NO₃)₂

(c) Mg²⁺CO₃^2- →Mg²CO₃² → Mg₂(CO₃)₂ →Mg_2/2(CO₃)_2/2 → MgCO₃

(d) Zn²⁺ SO₄^2- → Zn²SO₄² →Zn₂(SO₄)₂  → Zn_2/2(SO₄)_2/2  → ZnSO₄

(e) Zn²⁺NO₃^1- →Zn²NO₃¹→ Zn(NO₃)₂

(f) Zn²⁺CO₃^2- → Zn²CO₃² →Zn₂(CO₃)₂ → Zn_2/2(CO₃)_2/2 → ZnCO₃

Because they are hygroscopic in nature and absorb moisture from atmosphere in which they ultimately dissolve.

Commercial unit of Energy is Kilo Watt per hour denoted by kWh. 

1kWh = 3600000 Joules 

Energy Consumed in 1 hour 

60 W = 60 j/s 

1 hour = 60×60 seconds 

⇒ Energy consumed in 1 hour = 60 × 60 × 60 = 216000 j 

216000 Joules of energy is consumed in 1 hour.

Answer is Nitrogen

(a) Soluble bases arp called alkalies, e.g. sodibm hydroxide is an alkali. 

(b) HCl, HNO₃ionise in aqueous solution, whereas alcohol and glucose do not show acidic characters because they do not ionise in aqueous solution.

Hydrogen ions in HCl and HNO₃ are produced in the presence of water. Hydrogen ions cannot exist alone, but they exist after combining with water molecules. Thus hydrogen ions must always be shown as (aq) or hydronium ion (H₃O⁺)
The reaction is
HCl_(aq) → H⁺ + Cl^–
H⁺ + H₂O → H₃O⁺
Alcohol and glucose even though they contain Hydrogen they do not show acidic character like HCl and HNO₃.

Basicity of an acid is the number of hydrogen ions which can be produced from one molecule of the acids on complete dissociation. Acetic acid, CH.COOH gives one H⁺ per molecule the acid, hence acetic acid is monobasic i.e., its basicity is one.

CH₃COOH (aq) ⇋ CH₃COO^-(aq) + H⁺ (aq)

Acidity of a base is the number of hydroxyl ions which can be produced from one molecule of the base on complete dissocation. Ca(OH)₂ (calcium hydroxide) gives two hydroxyl ions per molecule of the base, hence calcium hydroxide is diacidic i.e., its acidity is two.

(a) Potassium Nitrate 

(b) KOH + HNO₃ → KNO₃ + H₂O

Pb(NO₃)₂ + 2NaCl → PbCl₂ + 2NaNO₃

D) Both B & C

Nitric acid (HNO₃) → Monobasic

Acetic add (CH₃COOH) → Monobasic

Phosphoric add (H₃PO₄) → Tribasic.

HNO₃ → H⁺ + NO^-₃

Basicity -1

Water soluble bases are called alkali. 

(D) Copper (II) oxide

(a) The anhydride of following acids are:

(i) Sulphurous acid: SO₂

(ii) Nitric acid: N₂O₅

(iii) Phosphoric acid: P₂O₅

(iv) Carbonic acid : CO₂

(b) Acids present in following are:

Vinegar: Acetic acid

Grapes: Tartaric acid and Malic acid

Lemon: Citric acid

(c) (i) H⁺ ion turns blue litmus red.

(ii) OH^- ion turns red litmus blue.

1 watt is the power of an agent which does the work at the rate of 1 joule per second. 

1W = 1 j/s

1. Ant sting: 

An ant sting is acidic as it contains formic acid while the wasp sting is basic in nature. 

2. Wasp sting: 

Ant sting can be neutralised by a base like baking soda while wasp sting is neutralised by an acid like vinegar (acetic acid).

Methanoic acid (HCOOH). Use of Baking soda can give relief on the stung area when applied on it.

(4) Acetic acid

Basicity: The basicity of an acid is defined as the number of hydronium ions (H₃O⁺) that can be produced by the ionization of one molecule of that acid in aqueous solution.

The basicity of following compounds are:

Nitric acid: Basicity = 1

Sulphuric acid: Basicity =2

Phosphoric acid: Basicity =3

Given 

Mass of object (m) = 10 Kg. 

Height (h) = 6 m. 

Acceleration due to gravity (g) = 9.8m/s² 

Potential Energy of Object = mgh 

= 10×9.8×6 = 98×6 

= 588 J 

Energy possessed by an object is 588 Joule.

Correct answer is KE = 1/2 mv²