The process used to separate oil and water is:
  • Distillation
  • Separating funnel
  • chromatography
  • Sublimation
In which of the following the constituents are present in any ratio?
  • Mixture
  • Colloid
  • Solution
  • Compound
Salt can be obtained from sea water by:
  • Decantation
  • Evaporation
  • Sublimation
  • Filtration
Which of the following is considered to be a pure substance?
  • Granite
  • Milk of magnesia
  • Muddy water
  • Sodium chloride
Which of the following is a compound?
  • Graphite
  • Hydrogen sulphide
  • Bronze
  • Stainless steel
White gold is used in jewelry and contains two elements, gold and palladium. A jeweler has two different samples that are both identical in appearance and have a uniform composition throughout. What can be said about the samples?
  • They are homogeneous mixtures and be classified as metallic alloys.
  • The samples are heterogeneous mixtures that can be separated using magnetic properties.
  • The materials are heterogeneous mixtures and can be classified by their components.
  • The samples have variable compositions and are classified as metallic solutions.
Distillation is a good separation technique for:
  • Solids
  • Gases
  • Solid alloys
  • Liquids
Two substances A and B when bought together form a substance C with the evolution of heat. The properties of C are entirely different from those of A and B. the substance C is:
  • None of these
  • An element
  • A mixture
  • A compound
Air is regarded as a mixture because:
  • It's temperature may change
  • Its composition may vary
  • It's pressure may very
  • Its volume changes under different conditions
A mixture of ZnCl2 and PbCl2 can be separated by:
  • Adding acetic acid
  • Sublimation
  • Crystallization
  • Distillation
Compounds:
  • Contain the only type of element
  • Are different kinds of atoms chemically combined with each other?
  • Can be separated by their physical properties
  • Are the same as mixtures?
Which component of the mixture ( Fe + S ) reacts with dil. HCI and gives hydrogen gas?
  • Sulphur
  • Iron
  • Both
  • none
Why do suspended particles settle in muddy water over time but not in milk?
  • Because muddy water contains larger particles that settle due to gravity, while milk has smaller particles that remain suspended.
  • Because milk particles are heavier than those in muddy water, so they float.
  • Because muddy water is denser than milk, so particles settle faster.
  • Because milk is a solid and muddy water is a liquid.
Evaporation is different from boiling in that:
  • Evaporation occurs at any temperature, while boiling occurs at a specific temperature.
  • Evaporation happens only at high temperatures, while boiling happens at low temperatures.
  • Evaporation and boiling both occur only at the boiling point.
  • Evaporation is a rapid process, while boiling is a slow process.
Why do you see bright rays of sunlight when it passes through small gaps between the leaves of a dense tree?
  • Because sunlight is scattered and diffracted as it passes through small gaps, creating bright rays.
  • Because the leaves absorb all the sunlight, leaving only bright rays.
  • Because sunlight is reflected off the leaves, forming bright rays.
  • Because the tree produces its own light, resulting in bright rays.
Is the mixture of oil and water homogeneous or heterogeneous? Can you think of some other heterogeneous mixtures?
  • The mixture of oil and water is heterogeneous. Examples of other heterogeneous mixtures include sand and water, salad, and granite.
  • The mixture of oil and water is homogeneous. Examples of other homogeneous mixtures include sand and water, salad, and granite.
  • The mixture of oil and water is homogeneous. Examples of other homogeneous mixtures include salt water, air, and vinegar.
  • The mixture of oil and water is heterogeneous. Examples of other heterogeneous mixtures include salt water, air, and vinegar.
Are the particles visible in each mixture? Record your observations for: A. Salt and water B. Chalk powder and water C. Milk and water
  • A. Salt and water: Particles are not visible. B. Chalk powder and water: Particles are visible. C. Milk and water: Particles are not clearly visible, but the mixture is not transparent.
  • A. Salt and water: Particles are visible. B. Chalk powder and water: Particles are not visible. C. Milk and water: Particles are clearly visible.
  • A. Salt and water: Particles are not visible. B. Chalk powder and water: Particles are not visible. C. Milk and water: Particles are not visible.
  • A. Salt and water: Particles are visible. B. Chalk powder and water: Particles are visible. C. Milk and water: Particles are not visible.
Direct the light from a laser pointer through the beakers containing the mixtures and observe it from the side of the beaker in a direction perpendicular to the laser beam. Record your observations for:
  • A. Salt and water: The laser beam is not visible in the mixture. B. Chalk powder and water: The laser beam is visible as it scatters due to the particles. C. Milk and water: The laser beam is visible as it scatters due to the colloidal particles.
  • A. Salt and water: The laser beam is visible as it scatters due to the particles. B. Chalk powder and water: The laser beam is not visible in the mixture. C. Milk and water: The laser beam is not visible in the mixture.
  • A. Salt and water: The laser beam is visible as it scatters due to the colloidal particles. B. Chalk powder and water: The laser beam is not visible in the mixture. C. Milk and water: The laser beam is not visible in the mixture.
  • A. Salt and water: The laser beam is visible as it scatters due to the particles. B. Chalk powder and water: The laser beam is visible as it scatters due to the colloidal particles. C. Milk and water: The laser beam is not visible in the mixture.
Predict what you would observe in each of the beakers if you leave them undisturbed for a few minutes.
  • A layer of sediment settles at the bottom of each beaker.
  • The contents of each beaker remain completely mixed.
  • The liquid in each beaker evaporates completely.
  • The beakers change color due to a chemical reaction.
Set up a filtration apparatus and filter each mixture separately. Is there any residue left on the filter paper?
  • Yes, there is residue left on the filter paper.
  • No, there is no residue left on the filter paper.
  • The residue dissolves completely in the filtrate.
  • The filter paper changes color but no residue is left.
Based on your observations, these are the same types of mixtures or are they different?
  • They are the same types of mixtures.
  • They are different types of mixtures.
  • They are neither the same nor different.
  • They are both homogeneous mixtures.
What is a solute?
  • A solute is the substance that gets dissolved in a solution.
  • A solute is the substance that dissolves other substances in a solution.
  • A solute is the liquid part of a solution.
  • A solute is the substance that evaporates from a solution.
What is a solvent?
  • A solvent is the substance that dissolves the solute in a solution.
  • A solvent is the substance that gets dissolved in a solution.
  • A solvent is the solid part of a solution.
  • A solvent is the gas released during a chemical reaction.
In the mixture of sugar and water, which is the solute and which is the solvent?
  • Sugar is the solute and water is the solvent.
  • Water is the solute and sugar is the solvent.
  • Both sugar and water are solutes.
  • Both sugar and water are solvents.
The right proportion is always essential when preparing a solution because:
  • it ensures the solution has the desired properties and effectiveness.
  • it makes the solution look colorful.
  • it allows the solution to be prepared faster.
  • it prevents the solution from evaporating quickly.
Who is Dilip Mahalanabis and what is his contribution to science?
  • Dilip Mahalanabis is an Indian paediatrician who developed and implemented the treatment for dehydration caused by diseases such as diarrhoea and cholera. He formulated the ORS that has revolutionised rehydration therapy.
  • Dilip Mahalanabis is a renowned physicist known for his work in quantum mechanics.
  • Dilip Mahalanabis is a famous botanist who discovered several new plant species.
  • Dilip Mahalanabis is a chemist who invented a new method for synthesizing antibiotics.
If 10 g of salt is dissolved in 90 g of water, calculate the mass by mass percentage of the solution formed.
  • 10 % m/m
  • 5 % m/m
  • 20 % m/m
  • 15 % m/m
If 5 g of glucose is dissolved in water to make 100 mL of solution, calculate its concentration in mass by volume percentage.
  • 5 % m/v
  • 0.5 % m/v
  • 10 % m/v
  • 0.05 % m/v
A common talcum powder contains 4% w/m zinc oxide, which acts as an antiseptic. How much zinc oxide is present in 300 g of the talcum powder?
  • 12 g
  • 4 g
  • 8 g
  • 16 g
What is the % v/v of orange juice concentrate in the mixture you prepared?
  • 10%
  • 25%
  • 50%
  • 75%
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