Liquid States MCQ Quiz - Objective Question with Answer for Liquid States - Download Free PDF

The Correct answer is Liquids have loosely packed molecules that slide past each other.

Key Points

• Liquids have loosely packed molecules, meaning their particles are not tightly bound as in solids.
• The molecules in a liquid are held together by intermolecular forces, but these forces are weak enough to allow the molecules to move freely and slide past one another.
• Liquids exhibit a property called fluidity, which allows them to flow and take the shape of the container they occupy.
• Due to the weak intermolecular forces, liquid molecules have enough kinetic energy to overcome these forces partially, enabling free movement.
• This ability to flow distinguishes liquids from solids, where molecules are rigidly fixed, and gases, where molecules move independently with negligible intermolecular forces.
• The sliding motion of molecules gives liquids unique properties such as viscosity, which determines how easily a liquid flows.
• Examples of liquids that exhibit flow include water, oil, and milk, where the molecular structure enables their fluid behavior.

 Additional Information

• Liquids have no intermolecular forces
  • This statement is incorrect because all liquids have intermolecular forces, although they are weaker compared to solids. These forces are crucial for maintaining the liquid state.
  • Examples of intermolecular forces in liquids include hydrogen bonding, van der Waals forces, and dipole interactions.
• Liquids do not have kinetic energy
  • This is incorrect as molecules in a liquid possess kinetic energy, which allows them to move and slide past each other.
  • Kinetic energy is directly related to the temperature of the liquid, meaning higher temperatures result in faster molecular movement.
• Liquid molecules move randomly without any restriction
  • This is not entirely accurate because while liquid molecules do move randomly, their motion is influenced by intermolecular forces, which impose some restrictions.
  • Complete random motion is characteristic of gases rather than liquids.

The Correct answer is Both statements I and II are correct.

Key Points

• Liquids are one of the three primary states of matter, alongside solids and gases, characterized by distinct physical properties.
• Statement I: Liquids have fixed volume but no fixed shape.
  • Liquids occupy a definite volume due to the relatively strong intermolecular forces between their particles.
  • However, unlike solids, liquids do not have a fixed shape and take the shape of their container because the particles can slide past one another.
• Statement II: The rate of diffusion of liquids is higher than that of solids.
  • Diffusion is the process by which particles spread out to evenly occupy a space.
  • The rate of diffusion in liquids is faster than in solids because liquid particles are in a state of continuous motion and have weaker intermolecular forces compared to solids.
  • This property is crucial in processes like mixing of liquids and biological functions such as nutrient transport in cells.
• Both statements are correct because they describe fundamental properties of liquids observed under normal conditions.

 Additional Information

• Liquid State Characteristics:
  • Viscosity: A measure of a liquid's resistance to flow. For instance, honey has a higher viscosity compared to water.
  • Surface Tension: Liquids exhibit surface tension due to cohesive forces between molecules. This property enables phenomena like the formation of water droplets.
  • Compressibility: Liquids are generally incompressible due to the close packing of their molecules.
  • Evaporation: Liquids can change into gases at their surface even below the boiling point due to the kinetic energy of molecules.
• Applications of Liquid Properties:
  • The property of taking the shape of the container is utilized in designing hydraulic systems like brakes and lifts.
  • Diffusion in liquids is significant in chemical and biological processes, such as the mixing of solutions and nutrient absorption.

The correct answer is It has fixed volume but not fixed shape.

Key Points Liquids and Their Characteristics:

• Liquids are one of the three primary states of matter, along with solids and gases.
• A key characteristic of liquids is that they have a definite volume.
• This means that a given amount of liquid will always occupy the same amount of space.
• However, liquids do not have a fixed shape.
• They take the shape of the container they occupy.
• This is because the particles in a liquid are able to move past each other, unlike the particles in a solid, which are fixed in place.
• Liquids are generally incompressible, or only very slightly compressible.
• This is due to the close proximity of the particles within the liquid.
• The forces between liquid particles are strong enough to maintain a fixed volume, but weak enough to allow them to flow.
• Liquids exhibit the property of fluidity, which means they can flow.
• This fluidity is due to the ability of the particles to slide past each other.
• The surface of a liquid at rest is generally horizontal.
• Liquids can exhibit surface tension, which is a force that causes the surface of a liquid to behave like a stretched elastic membrane.
• Viscosity is another characteristic of liquids, which is a measure of their resistance to flow.
• Liquids have a density that is typically between that of solids and gases.
• Liquids can evaporate, which is the process of a liquid changing into a gas.
• Liquids can also condense, which is the process of a gas changing into a liquid.
• The temperature of a liquid affects its properties, such as viscosity and density.
• The particles in a liquid have kinetic energy, which increases with temperature.
• Liquids can dissolve various substances, forming solutions.
• Liquids are essential for numerous biological and industrial processes.
• The intermolecular forces in liquids are stronger than in gasses, but weaker than in solids.
• The ability of the particles to move freely within the liquid allows it to take the shape of its container.

Given, the work needed to decrease this coverage by 1 cm² is 25.0 × 10^-7 J. Surface tension of pure water is 0.027 N/m. Surface pressure per cm² is 25 × 10^-7J.

\(\text{ per }\mathrm{m}^2\text{ is }\frac{25\times 10^{-7}}{10^4}\mathrm{J}\Rightarrow 25\times 10^{-3}\mathrm{J}\)

Surface pressure (n) = ν₀ - ν

ν = 0.072 − 0.025

ν = 0.072 - 0.025 = 0.047

So, the surface tension of the film is 0.047 N/m.

Key Points

• Petrol is a liquid and takes the shape of the container it is in.
• Tungsten and Iron are solid materials that do not change shape based on the container.
• Paper is also a solid and maintains its shape unless physically altered.
• Liquids, unlike solids, have the ability to flow and adapt to the shape of any container.
• Petrol, being a liquid, exhibits properties such as viscosity and surface tension, which are characteristic of liquids.

Additional Information

• Liquids have a fixed volume but no fixed shape, which differentiates them from solids and gases.
• The behavior of liquids in containers is governed by principles of fluid dynamics and hydrostatics.
• Understanding the properties of liquids is crucial in various applications, including engineering, chemistry, and daily life.

The correct answer is the air pressure is less.

Key Points

• The boiling point of water is lower at higher altitudes due to the decreased atmospheric pressure.
• A liquid/water boils when its vapour pressure exceeds the total atmospheric pressure over it.
• Unlike Pressure Cooking where the boiling point is higher due to high pressure,  at higher-altitude cooking takes place at lower atmospheric pressure.
  • This requires more cooking time.
  • Water boils at 212º F at sea level. 
  • At higher altitudes, the boiling point of water decreases, which leads to longer cooking times.
• Relation of Pressure and altitude:
  • Pressure decreases with increasing altitude.

• Silver (Ag) does not react with Oxygen (O) even at a high temperature because of the less reactivity of Sliver.
• Reactive elements displace the less reactive elements in a chemical reaction.
• The reactive element loose electrons readily to attain stable electronic configuration and thus reduce another element and oxidize themselves.
• Reactive metals are found on top of the reactivity series.
• The order of reactivity of metals is given below.

The correct answer is Mercury.

Key Points

• The best conductor of heat among liquids is Mercury.
• Mercury
  • Symbol- Hg
  • The Greek name of mercury is hydrargyrum from where its symbol is taken.
  • Atomic number: 80
  • Atomic mass: 200 u
  • Melting point: -38 °C
  • Boiling point: 356.7 °C
  • It is the only metal element to exist in the liquid state at room temperature i.e. in the range 20 to 25 °C 
  • It is also called liquid silver.
  • It is used in thermometers because it can record the slightest change in temperature.

Additional Information

• Solids are generally very good conductors of heat.
• Silver and copper are excellent conductors of both heat and electricity.
• Alcohol is a class of organic compounds in which one or more hydroxyl (-OH) groups attached to a carbon atom of an alkyl group (hydrocarbon chain).
  • Alcohol is a bad conductor of heat and electricity as it does not ionize.
  • Alcohol doesn't have free moving ions.
• Ether is a class of organic compounds in which an oxygen atom is bonded to two alkyl or aryl groups.
• Thermal conductivity is defined as the amount of heat per unit time per unit area that can be conducted through a plate of unit thickness of a given material, the faces of the plate differing by one unit of temperature.
• It is denoted by k, λ, or κ.
• It is quantified using the International Systems of Unit (SI unit) of \( W/m•K\) (Watts per meter per degree Kelvin).

Important Points

The correct answer is Evaporation.

Key Points

• Evaporation is the process by which water changes from a liquid to a gas or vapor. Evaporation is the primary pathway that water moves from the liquid state back into the water cycle as atmospheric water vapor.
• The oceans, seas, lakes, and rivers provide nearly 90 percent of the moisture in the atmosphere via evaporation, with the remaining 10 percent being contributed by plant transpiration.

Important Points

• Sublimation is the conversion between the solid and the gaseous phases of matter, with no intermediate liquid stage. an example of sublimation is naphthalene, dry ice.
• Condensation is the process by which water vapor in the air is changed into liquid water. Condensation is crucial to the water cycle because it is responsible for the formation of clouds. Condensation is the opposite of evaporation.

The correct answer is 5 NTU.

Key Points

• According to  the Bureau of Indian Standards (BIS)(IS -10500 ∶ 2012), the maximum permissible limit of turbidity in potable water should be 5NTU
• Turbidity levels should be maintained between 1 and 5 NTU to keep the desirable drinking water quality as per the Bureau of Indian Standards.
• Turbidity in water means Turbidity is the measure of relative clarity of a liquid.
• Turbidity is produced by suspended particulate matter like plankton, inorganic and organic matter.

  Additional Information

• Turbidity is measured in NTU: Nephelometric Turbidity Units.
• The instrument used for measuring it is called a nephelometer or turbidimeter.
• It measures the intensity of light scattered at 90 degrees as a beam of light passes through a water sample.
• It is essential to eliminate the turbidity of water in order to effectively disinfect it for drinking purposes.

The correct answer is Heat is absorbed.

• When ice is converted into water then it absorbs all the heat energy without an increase in its temperature.

Key Points

• When ice(solid-state) is converted into water (liquid state), heat is absorbed by ice (solid-state) meaning solid transforms into liquid.
• In this transformation, heat is absorbed and the crystalline nature of ice is broken, and as we have well-separated water molecules.
• For instance, when we take out the ice from the freezer and keep it in an atmospheric temperature or warm room, the ice would absorb heat from the warm air and will start melting.

The correct answer is Liquid

Key Points

• Water shows anomalous behaviour when heated i.e., the amount of water decreases with an increase in temperature from 0°C to 4°C and beyond that, increases with an increase in temperature.
• At 12°C, the physical state of water is Liquid. Hence option 1 is correct.
  • ​It is liquid at 25°C also.
• The density of water is maximum at 4°C.

Additional Information

• At 0°C, the physical state of water is solid or ice because a phase change process takes place at that temperature.
  • At 100°C, the physical state of water is gas and that temperature is the boiling point of the water where the water evaporates.
• Superionic water is a phase of water that exists at extremely high temperatures.

The correct answer is Turbidity.

Key Points

• Turbidity is the measure of the relative clarity of a liquid.
• It is an optical characteristic of water and is a measurement of the amount of light that is scattered by material in the water when a light is shined through the water sample.
• The higher the intensity of scattered light, the higher the turbidity.
• The distance at which the disk disappears is the water clarity reading, which is recorded in centimetres.​

Additional Information

• Turbidity is commonly measured in Nephelometric Turbidity Units (NTU).
• The nephelometric method compares how light is scattered in a water sample against the amount of light scattered in a reference solution.
•  An electronic hand-held meter is often used to measure turbidity.
• The WHO (World Health Organization), establishes that the turbidity of drinking water shouldn't be more than 5 NTU, and should ideally be below 1 NTU.

The correct option is Bromine.

Key Points

• Bromine is a non-metal which is found in a liquid state.
• The atomic symbol of bromine is Br.
• It is present in group 17 of the periodic table.
• Its atomic number is 35 and there are 7 electrons present in its valence shell.
• it is it belongs to the halogen family as it has a strong attractive dispersion force that causes it to be in liquid form at room temperature with a high boiling point.
• It has a sufficient amount of intermolecular interaction such as Vander Waal interaction to enter the liquid phase as Br₂.

Additional Information Iodine:

• The atomic symbol of Iodine is I.
• It is present in group 17 of the periodic table.
• Its atomic number is 53 and there are 7 electrons present in its valence shell.
• It is non-metal but it is lustrous.
• It is used in Goitre.
• It exists as I₂.

Carbon:

• The atomic symbol of carbon is C.
• It is present in group 14 of the periodic table.
• Its atomic number is 6 and there are 4 electrons present in its valence shell.
• It is non-metal and it is brittle.
• It has catenation and tetravalency properties.

Sulphur:

• The atomic symbol of Sulphur is S.
• It is present in group 16 of the periodic table.
• Its atomic number is 16 and there are 6 electrons present in its valence shell.
• It is non-metal and it is brittle.
• It exists as S₈.
•  It has a yellowish appearance.

The correct answer is Salt decreases the melting point of the ice cream.

Concept:

• The melting point of a substance is a particular temperature at which the solid and liquid state of that substance attain an equilibrium.
• It can also be identified as the minimum temperature that is required to initiate the conversion of the solid-state of a matter to its liquid state.

 Explanation:

• The melting point of ice is 0ºC. At this temperature the ice in equilibrium with its liquid state, water.
• When only ice used to make ice cream, at 0ºC ice starts melting by absorbing the energy from its environment in the form of heat.
• Addition of salt to ice while making ice cream lowers the melting point of ice. 
• The temperature at which the equilibrium between ice and its liquid state will be achieved is lowered.

Therefore, salt is added to ice creams to decrease the melting point of ice cream.

Additional Information

• The same principle is used and applied to clear the snow from roads during snowfall.
• The depression in freezing point depends upon the concentration of salt added.