Explain why the gas fizzes out when soda water bottle is opened?

1 Answer

Answer :

Ans. In soda water bottle carbon dioxide gas is dissolved under pressure. As soon as the bottle is opened, the pressure inside the bottle tends to decrease, so the solubility decreases and gas escapes out.

Related questions

Description : Why fragrance of perfume spread in all the room when it is opened in one corner of the room? Write name of this phenomena.

Last Answer : This is because the molecules of the perfume are in higher concentration where it is opened, so it begins to move towards the area where their concentration is lower. This phenomenon is called diffusion.

Description : What will be the effect on equilibrium if (i) a catalyst is added to it (ii) An inert gas is added at constant volume

Last Answer : Ans. (i) The state of equilibrium is not disturbed on adding catalyst rather it is attained quickly. (ii) No effect on state of equilibrium

Description : What happens to the dissociation of PCl5 in a closed vessel if He gas is introduced into it at the same temperature?

Last Answer : Ans. No effect.

Description : Which gas law governs Isothermal process ?

Last Answer : Ans. Boyle’s law.

Description : What is meant by compressibility factor of gases? How does its value deviate from that of an ideal gas in case of real gases and what does it indicate?

Last Answer : Ans. It is the ratio of the product PV to nRT. Z = PV/nRT. For ideal gas its value is unity. Z < 1 indicates negative deviation i.e. gas is more compressible due predominance of attractive forces. Z > 1 indicates positive deviation i.e. gas is less compressible due predominance of repulsive forces.

Description : Can a gas with a = 0 be liquefied?

Last Answer : Ans. A gas with a = 0 means absence of intermolecular forces. Hence such a gas cannot be Liquified.

Description : What would have the effect on the gas pressure if collisions between the gas molecules are not elastic?

Last Answer : Ans. The gas pressure would gradually become zero as molecules will gradually slow down and ultimately settle down due to constant loss of energy.

Description : Arrange solid, liquid and gas in order of energy. Give reason.

Last Answer : Ans. Solid < liquid < gas. This is because solid absorb energy to change into a liquid which further absorb energy to change into a gas.

Description : Justify the statement. A gas neither has a fixed shape nor a fixed volume.

Last Answer : Gas molecules possess large intermolecular spaces therefore the cohesive forces between them are insignificant. This is why a gas has no fixed shape or volume

Description : How gas exerts pressure on a container?

Last Answer : Gas molecules have weak cohesive forces present between them, so these are widely separated from each other and move freely in all directions so they collide with each other and with the walls of container, in this way pressure is created.

Description : Explain the effect of increasing the temperature of a liquid, on intermolecular forces operating between its particles. What will happen to the viscosity of a liquid if its temperature is increased? Arrange the following in increasing order of viscosity-water, hexane, glycerine.

Last Answer : Ans. On increasing the temperature , the kinetic energy of liquid molecules increases so that it can overcome the attractive forces between the molecules and hence liquid can flow more easily i.e. viscosity decreases. Order of increasing viscosity : hexane < water < glycerine.

Description : Out of NH3 and N2 which will have a) larger value of ‘a’ b)larger value of ‘ b’ .Explain.

Last Answer : Ans. a) NH3 will have larger value of a because of H – bonding. b) NH3 will have larger value of b due to larger molecular size.

Description : Use the information and data given below to answer the questions Stronger intermolecular forces result in higher boiling point Strength of London forces increases with the number of electrons in the molecule ... here? (c) Why is the boiling point of HF highest while that of HCl lowest?

Last Answer : Ans :( a) In the molecules HCl, HBr and HI, dipole-dipole interaction and London forces are present. (b) Dipole moment of HCl > HBr > HI but boiling point of HCl < HBr

Description : Explain Hess’s law.

Last Answer : Ans. It states that the enthalpy change of the reaction remains the same whether the reaction is carried out in one step or several steps, i.e., ∆H = ∆H1 + ∆H2 + ∆H3 +…………

Description : We are consuming a lot of electrical energy, solar energy etc Do you, therefore, conclude that energy of the universe is continuously decreasing? Explain. Which other thermodynamic quantity is continuously increasing or decreasing?

Last Answer : Ans. No, energy of the universe remains constant (law of conservation of energy). Entropy of the universe is continuously increasing.

Description : When ΔH>0 and ΔS< 0, reaction is never spontaneous. Explain.

Last Answer : Ans. When ΔH > 0 , energy factor opposes the reaction . When ΔS< 0, i.e. randomness decreases, this factor also opposes the process. As both factors oppose the process, reaction is never spontaneous.

Description : Define the term system and surroundings. Explain the different types of system.

Last Answer : Ans. System : The part of the Universe which is under investigation. Surroundings: The remaining part of the Universe other than system. The system and surroundings are separated by well defined boundary. Types of system: (i) Open system (ii) Closed system (iii) Isolated system

Description : Explain how can gases be liquefied?

Last Answer : Ans. Gases can be liquefied by decrease of temperature and increase of pressure.

Description : Explain the absolute zero (in terms of volume) with the help of isobar.

Last Answer : Ans: At absolute zero ,volume approach to zero and below this temperature, the volume will be negative, which is meaningless. Hence absolute zero is the lowest possible temperature .

Description : On the basis of Boyle’s Law explain why mountaineers carry oxygen cylinder with them.

Last Answer : Ans. At high altitude as the atmospheric pressure is low , the air is less dense. As a result less oxygen is available for breathing .

Description : What is the molarity of pure water?

Last Answer : Ans: 55.5M

Description : Applying Le- Chatelier's principle, predict the effect of temperature and pressure on evaporation of water.

Last Answer : Ans Evaporation of water can be represented as water + heat water vapours: i) With increase in pressure- the equilibrium tend to shift in direction where there is decrease in the vol. i.e. ... left. ii) with increase in temperature- the equilibrium shifts to right as it is an endothermic reaction.

Description : Which measurable property become constant in Water Water vapors equilibrium at constant temperature

Last Answer : Ans. Vapour pressure.

Description : Water can be lifted into the water tanks at the top of the house with the help of a pump. Then why is not considered to be spontaneous?

Last Answer : Ans. A spontaneous process should continue taking place by itself after initiation . But this is not so in the given case because water will go up so long as the pump is working.

Description : What is the value of ∆G where ice and water are in equilibrium?

Last Answer : Ans. ∆G=0

Description : i)Vapour pressure increases with increase in temperature. ii)Giycerine is more viscous than water.

Last Answer : Ans. i) At higher temperature inter particle attraction weakens and more number of mole cules escape to vapour. ii) As interparticle forces are stronger in glycerine.

Description : Which type of intermolecular forces are effected in each of the following process: (i)Sublimation of iodine. (ii)Evaporation of water.

Last Answer : Ans. (i) Sublimation of iodine : Dispersion forces. (ii)Evaporation of water : Hydrogen bond.

Description : How fishes remain alive under frozen water (ice) ponds?

Last Answer : When water freezes into ice, the empty spaces are left between water molecules, due to hydrogen bonding. So as a result ice becomes lighter then water and start floating on surface of water. It is also non-conductor of heat, so water beneath it doesn’t freezes and fishes remain alive under it.

Description : Out of carbon(diamond)and carbon (graphite) whose enthalpy of formation is taken as zero?

Last Answer : Ans. Enthalpy of formation of carbon in the form of graphite is taken as zero because it is a more commonly found in stable form of carbon.

Description : Why is the PH of blood remains almost constant?

Last Answer : Ans: Blood is a buffer solution and resist the change in PH

Description : How much is the percentage ionization of an electrolyte to classified is as 'weak electrolyte'?

Last Answer : Ans:

Description : What type of substances are generally called 'electrolyte'?

Last Answer : Ans: Acid, bases and salts

Description : Write the effect of temperature on Equilibrium constant.

Last Answer : Ans. The value of Equilibrium constant changes with the temperature. The increase in rate depends upon activation energy .As the activation energy are different for forward & backward direction .So temperature will ... & backward direction. As K= Kf/ Kb ,so the state of equilibrium will be altered.

Description : Why the Equilibrium constant is taken as dimensionless?

Last Answer : Ans. Activities are used in place of molar Conc. These represent the concentration or pressure with respect to standard state.

Description : Write the significance of equilibrium constant?

Last Answer : Ans.The numerical value of equilibrium constant is a measure of the extent to which the reactants have been converted into products. A large value of K indicates large amount of ... its low value indicates less amount of reactants converted into products before achieving the equilibrium state.

Description : What are the conditions for getting maximum yield of NH3 by Haber’s process?

Last Answer : Ans. High conc. Of N2 &H2, Low Temp. & High Pressure.

Description : if the equilibrium constant for the reaction is 4.0, what will be the equilibrium constant for the reverse reaction.

Last Answer : Ans. Kc=1/4

Description : what do you mean by homogenous and heterogeneous equilibrium?

Last Answer : Ans. Homogenous;-It is that equilibrium reaction in which all the reactants and the products are in the same phase. Heterogeneous equilibrium: - It is that equilibrium reaction in which all the reactants and the products are in two or more phases

Description : Write Application of Equilibrium constant?

Last Answer : Ans. (i) To predict the extent of the reaction. (ii) To predict the direction of the reaction. (iii) To calculate the equilibrium concentration.

Description : Write characteristics of Chemical equilibrium.

Last Answer : Ans. (i) At equilibrium the rate of forward reaction becomes equal to rate of backward reaction. (ii) A chemical equilibrium established only if none of the products are allowed to escape out ... can be attained from either direction. (iv) Catalyst does not alter the state of equilibrium.

Description : What will be the value of K ,If reaction is reversed?

Last Answer : Ans. The value of K will get inversed.

Description : what is Equilibrium?

Last Answer : Ans : Equilibrium represents the state of process in which properties such as temperature, pressure ,concentration of the system do not show any change with the passage of time. OR The state in which rate of forward reaction becomes equal to the rate of backward reaction.

Description : Is the bond energy of all the four C-H bonds in CH4 molecule equal? If not then why ? How is C-H bond energy then reported?

Last Answer : Ans. No because after breaking of C-H bonds one by one, the electronic environments change. The reported value is the average of of the bond dissociation energies of the four C-H bonds.

Description : What is the sign of enthalpy of formation of highly stable compound?

Last Answer : Ans. Negative.

Description : Which have more entropy real crystal or ideal crystal and why?

Last Answer : Ans. Real crystal has more entropy because it has more disorderness.

Description : Predict the sign of ∆S for (a) the process of evaporation (b) the process of freezing.

Last Answer : Ans. (a) ∆S =+ve (b) ∆S=-ve

Description : Two ideal gases under same pressure and temperature are allowed to mix in an isolated system. What will be the sign of entropy change?

Last Answer : Ans. Entropy change (∆S) is positive. It is because disorder or degree of freedom increases on mixing.

Description : Under what condition, the heat evolved or absorbed in a reaction is equal to its free energy change?

Last Answer : Ans. As ΔG = ΔH – TΔS. Thus, ΔG = ΔH only when either the reaction is carried out at 0^0 K or the reaction is not accompanied by any entropy change, i.e., ΔS = 0

Description : Write an expression in the form of chemical equation for the standard enthalpy of formation (∆Hf) of CO (g).

Last Answer : Ans. C(s) +1/2 O2(g) → CO (g)

Description : What is meant by entropy driven reaction? How can the reaction with positive change of enthalpy and entropy be made entropy driven?

Last Answer : Ans.The free energy change of a reaction is given by ΔG = ΔH - TΔS For a reaction to be spontaneous, ΔG should be -ve. If both ΔH and ΔS are positive ΔG can be -ve if TΔS>ΔH in magnitude. Thus, entropy ... is low, TΔS should be greater than ΔH (ii) If ΔS is small, T should be so large that TΔS>ΔH.