Solutions MCQ Quiz - Objective Question with Answer for Solutions - Download Free PDF

The correct answer is True solutions have a single-phase system, whereas colloids have a two-phase system.

Key Points

• A true solution is a homogeneous mixture of two or more substances.
• In a true solution, the solute particles are completely dissolved in the solvent, forming a single-phase system.
• A colloid is a heterogeneous mixture where the solute particles do not dissolve but are dispersed throughout the solvent.
• Colloids consist of a dispersed phase and a dispersion medium, forming a two-phase system.
• The particles in colloids are larger than those in true solutions but are still invisible to the naked eye.
• True solutions are transparent, while colloids can be opaque or translucent.

 Additional Information

• True solutions have visible solute particles, whereas colloids have invisible dispersed particles.
  • In true solutions, solute particles are not visible as they are at the molecular or ionic level.
  • In colloids, the dispersed particles are also invisible to the naked eye but are larger than those in true solutions.
• True solutions exhibit Brownian motion, but colloids do not.
  • Brownian motion is the random movement of particles in a fluid, observed in colloids rather than true solutions.
  • True solutions do not exhibit Brownian motion as their particles are too small to be observed under normal conditions.
• True solutions show the Tyndall effect, but colloids do not.
  • The Tyndall effect is the scattering of light by particles in a colloid, making the light beam visible.
  • True solutions do not show the Tyndall effect as their particles are too small to scatter light.

The correct answer is True solutions have a single-phase system, whereas colloids have a two-phase system.

Key Points

• True solutions are homogeneous mixtures in which the solute is completely dissolved in the solvent, forming a single-phase system.
• Colloids, on the other hand, are heterogeneous mixtures with two distinct phases: the dispersed phase (solute-like) and the dispersion medium (solvent-like).
• The particles in true solutions are molecular or ionic in size (<1 nm), whereas colloidal particles range from 1 nm to 1000 nm.
• True solutions do not scatter light and hence do not exhibit the Tyndall effect, while colloids do scatter light due to their larger particle size.
• True solutions are stable without any separation of components, whereas colloids may show sedimentation over time under certain conditions.

Additional Information

• Brownian motion: The random, zigzag motion of particles in a fluid medium, observed prominently in colloids due to their particle size. True solutions do not exhibit Brownian motion as their particles are too small.
• Tyndall effect: The scattering of light by particles in a colloid, making the light beam visible. True solutions do not exhibit this effect as their particles are too small to scatter light.
• Homogeneous vs. heterogeneous mixtures: True solutions are homogeneous (uniform throughout), while colloids are heterogeneous (two-phase system but appear uniform to the naked eye).
• Particle visibility: Solute particles in true solutions are invisible under a microscope, while colloidal particles can be seen under an ultramicroscope.
• Examples: True solutions include saltwater and sugar water. Colloids include milk (emulsion), fog (aerosol), and gelatin (gel).

The correct answer is - the association of molecules.

• Acetic acid has a molar mass of 60 g/mol.
• The acid dimerizes in benzene due to the presence of hydrogen bonding between its molecules.
• Due to this association of molecules,  the molecular weight of the acetic acid becomes double that of normal value.
• Hence, in benzene, acetic acid shows the molecular weight of 118 g/mol.

Additional Information

• Benzene is an organic chemical compound with the molecular formula C₆H₆.
• The benzene molecule is composed of six carbon atoms joined in a planar ring with one hydrogen atom attached to each.
• As it contains only carbon and hydrogen atoms, benzene is classed as a hydrocarbon. 

The correct answer is Option 2.

Key Points

• Water is a universal solvent: Water can dissolve more substances than any other liquid, which makes it essential for biological processes and various industrial applications.
• Water has a high boiling point: Water boils at 100°C (212°F) under standard atmospheric pressure, which is relatively high compared to other similar molecular compounds.
• Water is a poor conductor of electricity: Pure water does not conduct electricity well. Its conductivity increases with the addition of dissolved salts and minerals.
• Water exists in all three states on Earth: Water naturally occurs as a solid (ice), liquid (water), and gas (water vapor) in the Earth's environment.

Additional Information

• Universal Solvent:
  • Water's polarity allows it to dissolve a wide range of substances, making it crucial for chemical reactions in living organisms and industrial processes.
  • This property is essential for nutrient transport in biological systems and for the functioning of ecosystems.
• High Boiling Point:
  • Water's high boiling point is due to hydrogen bonding among water molecules, which requires significant energy to break.
  • This high boiling point helps regulate temperature in natural and artificial environments.
• Electrical Conductivity:
  • Pure water's low electrical conductivity is due to the lack of free ions; however, the presence of dissolved ions like sodium and chloride increases its conductivity.
  • Understanding water's conductivity is important for water quality assessment and various industrial applications.
• States of Water:
  • Water's ability to exist in three states is due to its unique molecular structure and hydrogen bonding.
  • This property is vital for Earth's climate system, influencing weather patterns and the hydrological cycle.

The correct answer is Both I and II are correct.

Key Points

• A solution is a homogeneous mixture: Homogeneous mixtures have a uniform composition throughout, such as salt dissolved in water (source: Chemistry LibreTexts).
• Soil is an example of a heterogeneous mixture: Heterogeneous mixtures have visibly different substances or phases, like soil which contains organic matter, minerals, air, and water (source: ScienceDirect).
• Homogeneous mixtures are characterized by having only one phase of matter, ensuring uniform properties (source: Encyclopedia Britannica).
• Heterogeneous mixtures can be separated into their components through physical means such as filtration, sieving, or decantation (source: National Science Foundation).

Additional Information

• Homogeneous Mixture:
  • Examples include solutions like sugar in water, air, and alloys.
  • In homogeneous mixtures, the solute and solvent are uniformly distributed at the molecular level (source: Royal Society of Chemistry).
• Heterogeneous Mixture:
  • Examples include mixtures like salad, oil and water, and granite.
  • Components in heterogeneous mixtures can be easily distinguished and separated physically (source: American Chemical Society).
• Solution:
  • A solution is a specific type of homogeneous mixture composed of two or more substances.
  • It involves a solute being dissolved in a solvent, forming a single-phase system (source: Chemguide).
• Mixture:
  • A mixture is a material made up of two or more different substances which are not chemically bonded.
  • Mixtures can be classified as either homogeneous or heterogeneous based on the uniformity of their composition (source: Khan Academy).

Concept: 

Mass by mass percentage: Mass percent is a way to express a concentration or to describe the component in a specific mixture.

• The composition of the solution can be represented in a mass percentage that shows the mass of solute present in a given solution quantity.
• The solute quantity is measured in the mass or by moles.
• The mass per cent is defined as the grams of solute per gram of solution for a solution, multiplied by 100 to get the percentage.
• Concentrating a Solution is the amount of solution present in a given quantity (mass or volume) of solution.

Mass % = (mass of solute/mass of solution) x 100

Calculation:

Given:

Solute mass (m) = 50 g, Solvent mass (M) = 350 g

Solution mass = m + M = 50 + 350

Solution mass = 400 g

Mass % = (mass of solute/mass of solution) x 100

The correct answer is Sugar in water.

Important Points

• Sugar in water is a homogeneous mixture.
• A Heterogeneous mixture has different proportions of its compound in a sample.
• A Homogeneous mixture has the same proportions of its compound in a sample.
• A Mixture in which solute particle does not dissolve, but get suspended is a suspension.
• A solution in which the substances are regularly suspended in a fluid is a Colloidal Solution.
• A true solution is a homogeneous mixture of two or more substances in which the substance dissolved in the solvent has a particle size of less than 10-9 m or 1 nm. 

The correct answer is 3 i.e. 46 grams.

Explanation:

• 1 mole of C2H5OH = Molecular mass of C₂H₅OH in grams
  • Mass of 2C + Mass of 6H + Mass of 1O
  • 12 × 2 + 1 × 6 + 16 × 1
  • 24 + 6 + 16
  • 46 grams

Concept:

Good and Bad Conductors of electricity

• Good Conductors are materials that allow an electric current to pass through them. 
  • Examples: Metals like copper, silver, etc are good conductors. Graphite is also a good conductor. 
  • They are used for making conducting wires. 
• Poor conductors are materials that do not allow an electric current to pass through them.
  • Examples: wood, diamond, plastic, pure water, etc. 
  • They are used to make switches, insulating covers, etc.

Pure water is a poor conductor of electricity. But when impurities are present in it, it may conduct electricity. 

Explanation:

• Pure water is a poor conductor of electricity. 
• Distilled water is pure water and hence poor conductor of electricity. 
• Tap water is not pure. It contains several other types of minerals and ions which conduct electricity. So, tap water is a good conductor of electricity. 
• The salt solution contains ions that conduct electricity, so the saltwater is a good conductor of electricity.

Therefore the correct option is Both tap and seawater. 

Solution: 

• A solution is a homogenous mixture of two or more substances.
• The minor component in the solution which is dissolved in the solvent (major component)  is called Solute.
• The major component of the solution which dissolves a solute (minor component) is called Solvent.

Here, in the above question, common salt is solute and water is solvent.  

The formula for mass by the Concentration of the solution is given bt 

= \(\dfrac{Mass of Solute}{Mass of Solution} \times100\)

Calculation:

Given:  

Mass of solute (common salt) = 50g 

mass of solvent (water)= 500g 

∴Concentration of the solution

=  \(\dfrac{Mass of Solute}{Mass of Solution} \times100\)mass of solutemass ofsolvent" id="MathJax-Element-2-Frame" role="presentation" style="display: inline; position: relative;" tabindex="0">mass of solutemass ofsolvent ����������������������

= (50/550) × 100

= 9.09%

Concentration of the solution =  9%

The correct answer is Amalgam.

Explanation:

• An Amalgam is an alloy of mercury with another metal.
• It may be a liquid, a soft paste or a solid, depending upon the proportion of mercury.
• These alloys are formed through metallic bonding, with the electrostatic attractive force of the conduction electrons working to bind all the positively charged metal ions together into a crystal lattice structure.
• Amalgams are used to make dental fillings, to bind to precious metals so they can be isolated later, and to produce mirror coatings.

Additional Information

• Saturated Solution - 
  • A solution which can not dissolve a further amount of solute at a particular temperature is called a saturated solution.
  • For example, when you keep adding sugar to the water, a time will reach when no more sugar will dissolve in the water and sugar will settle down at the bottom.
• Unsaturated Solution - 
  • An unsaturated solution is a solution that contains less than the maximum amount of solute that is capable of being dissolved.
  • Tea and the sugar solution is a good example of an unsaturated solution due to the reason that they dissolve more amount of sugar in them.
  • Once such solutions reach the saturation point, they get converted to a saturated solutions.
• Supersaturated Solution -
  • A supersaturated solution contains more dissolved solute than required for preparing a saturated solution and can be prepared by heating a saturated solution, adding more solute, and then cooling it gently.
  • Excess dissolved solute crystallizes by seeding supersaturated solution with a few crystals of the solute.

• A mixture of cement, gravel, coarse and water is called concrete.
• Mortar is composed of sand and cement.
• Slurry is a semi-liquid mixture made of cement or coal, manure, and water.

The correct answer is solution.

Key Points

• A homogeneous mixture of two or more substances is known as the Solution.
  • Mixtures are constituted by more than one kind of pure form of matter.
  • A solution has a solvent and a solute as its components.
  • The component of the solution that dissolves the other component in it (usually the component present in larger amounts) is called the solvent.
  • The component of the solution that is dissolved in the solvent (usually present in lesser quantity) is called the solute.

Additional Information

• Mixtures are classified into two categories:-
  • A heterogeneous mixture is a mixture of two or more chemical substances where the various components can be visually distinguished.
  • A homogeneous mixture is a type of mixture in which the composition is uniform and every part of the solution has the same properties.
• Pure substances are classified into two categories:-
  • Elements- A pure substance with only one kind of atom and cannot be broken into two or simpler substances by physical or chemical means is an element.
  • Compounds- A pure substance composed of two or more elements and chemically combined in a fixed proportion is called a compound.

The correct answer is 2 i.e. 18 grams.

Explanation:

• 1 mole of H2O = Molecular mass of H2O in grams
  • Mass of 2H + Mass of 1O
  • 2 × 1 + 16 × 1
  • 2 + 16
  • 18 grams

The correct answer is options (ii) and (iv).

Concept:

Mixtures:

• A mixture is a substance that consists of two or more elements or compounds not chemically combined together.
• For Example - Air is a mixture of gases like oxygen, nitrogen, argon, CO2, and water vapour. 

Explanation:

Types of Mixtures:

• Homogeneous Mixture:
  • Those mixtures, in which the substances are completely mixed together and are indistinguishable from one another, are called homogeneous mixtures.
  • For example Soda water, Soft drinks, lemonade, salt or sugar solution, etc.
• Heterogeneous Mixture:
  • Those mixtures in which the substances remain separate and one substance is spread throughout the other substance as small particles, droplets, or bubbles are called heterogeneous mixtures.
  • All the suspensions and colloids are heterogeneous mixtures.
  • For Example: - Sugar and sand mixture, muddy river water, soap solution.