11th class physics Chapter one Important Long Questions Prepare Online

Question: 1

Describe law of mass action?

Answer: 1

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Law of mass reaction: According to this law the rate at which a substance reacts is directly. Proportional to its active mass and the rate of a reaction directly proportional to the product of the active masses of the reacting substances. Derivation for equilibrium constant: Consider the following reversible reaction: A+B____kf_______ C+D kr Suppose (A) (B) (C) and (D) are moral concentration of A,B,C and D are respectively. So, a Rf * (A) (B) Rf-Kf (A) (B) Where Rf is rate of forward reaction while KF is a rate constant for forward reaction: Similarly, Rr * (C) (D) Rr = Kr (C) (D) where Rr is rate of reverse reaction while Kr is the rate constant for a reverse reaction. At equilibrium state Rf=Rr By putting the values of Eq 1 and 2 in Eq 3 we have Kf (A) (B) = Kr (C) (D) Kf = (C) (D) Kr = (A) (B) Kc = (C) (D) (A) (B) Kc is a equilibrium constant Part 6( b) Macroscopic Characteristics Dynamic means reaction is still continuing. A few characteristics are given below. Closed system: Dynamic equilibrium is attain able only in close vessel because substances can neither leave nor enter in close system. Concentration remain the same: Amount of reactants and products do not change at equilibrium state. Physical properties will not change: physical properties like colour density etc remain the same. Reaction does not stop: Reaction will not cease in dynamic equilibrium forward and reverse reaction keep on talking place at the same rate but in opposite direction. it can be shown as: Rates of forward _______ Rates of reaction Reverse reaction Equilibrium can be established from either side. An equilibrium state can be disturbed and again achieved under certain conditions of concentration pressure and temperature.

Question: 2

Question 7 (A) (B) Direction of reaction?

Answer: 2

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The direction of chemical reaction at a particular moment can be predicted by using reaction quotient which is products reactants ratio. It is calculated at any moment before a reaction attain equilibrium.It is represented by QC It predicts the direction of reaction by comparing the values of Qc with Kc, thus we can make following generalization about the direction of reaction. (1) If Qc < Kc the reaction goes from left to right.So reaction will proceed in the forward direction. forward Qc__________Kc large small The reverse reaction will occur to attain the equilibrium. (2) If Qc < kc then forward and reverse reaction take place at same rate. It implies that the equilibrium has established. Qc_________________Kc equilibrium Example: Consider the formation of hydrogen iodide at look H2 + I2______-2H1 Kc = 57.0 at look At any moment we withdraw the sample from reaction mixture and calculate the amount of H2.I2 and HI Suppose: [H2] t = 0.10 mol dm- 3 [I2] t = 0.20 mol dm -3 [HI]t = 0.40mol dm - 3 Where 't' subscript represent the measurements of concentration the equilibrium constant expression we get a value called the reaction quotient. Thus: Qc =___[HI] 2t___ [H2] t, [I2] t Qc = (0.40)2_____= 8.0 (0.10), (0.20) So, the value of Qc is less then Kc the reaction is not equilibrium.It needs more amounts of products.Therefore reaction will move in forward reaction. Part (B) 7 Data: Amount of H2 = 0.011 mol dm - 3 Amount of I2 = 0.011 mol dm - 3 Equilibrium concentration of, [HI] = 0.078 mol dm-3 Equilibrium constant value (kc)=? Solution: Equation: 2H1____________ H2+ I2 K2___[H2] [I2] [HI]2 By putting values we get: Kc=(0.11 mol dm -3) ( 0.011 mol dm-3) ( 0.078 mol dm -3 )2 kc= ( 0.000121) (0.006084) kc = 0.019

Question: 3

Q 5:<div>(a) describe the machanism of breathing?</div><div>(b) describe the structure and function of human respiratory system?</div>

Answer: 3

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Part (A)

The physical moment associated with the gaseous exchange are called breathing they are two phases breathing inhalation and exhalation.

Inspiration or inhalation:

During inspiration the rib muscle contract and rib muscle are raised. At the same dome shaped diaphragmcontract and is lowered. These moment increase the area of the thoracic cavity which reduce the pressure of lungs. A a result the lungs expand and the air pressure with them also decreases. The air from outside rushes into the lungs to equalize the pressure on both side.

Expiration or Exhalation:

After the gaseous the exchange in the lungs the impure air is expelled out in exhalationThe rib muscle relan bringing the back to the original position. The diaphragm also relam and it gets its raised dome-shaped. This reduces the shaped in chest cavity and increases the pressure on lungs.

The lungs contracts and the air is expelled out of them. Human breath 10____ 20 time per minute in normal circumstances i.e. at rest the rate of breathing is controlled by the respiratory center in the brain.

Part (B)

The nose enclosed the nosel cavity, it open to the outside through the opening called nostrils. The noral cavity is divided in two position by a wall. Each position is lined by fine hairs and maces. Which filter the dust particle as from the air. The noral cavity open into the pharynn by mean of two small opening called internal nostrils pharynn is a muscular passage and is corman to bath food and air glottis is narrowing opening at the floor of pharynn which lead into larynn .The larynn is a bone made of coutilliage.It is present b/w pharynn and trachea, it is also called vaic bone .Larynn continue to the trachea which is called the windpipe. It is about 12 cm long tube. Which lies in front of the esophagus.

Bronchi:

The bronchi also have cartiligae nose plates in their walls, each bronchus enter into the lungs of its side and then divide into small branches.

Bronchioles:

Within the lungs the bronchi divide into fine tubeles called as bornchioles.

Alveolar duct:

Each alveolar is open into a cluster a pauches called alveolar.

Alveoli:

The alveoli from respiratory system surface in human body. Each aleolus is a scak like structure alined by a single layer of epithelial cells. It is bond on the outside by a networle of capillaries.

Question: 4

Explain Newtons second law of motion

Answer: 4

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Statement: When a net force is applied on a body<it produces acceleration in the body in the direction of the force. The magnitude of this acceleration is directly proportional to the net force acting on body and inversely proportional to its mass

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11th Class Chapter one Physics Long Questions

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