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Test Paper 1: Chemical Changes
- What is a chemical change?
- A) A change in state of matter
- B) A change where new substances are formed
- C) A change that is reversible
- D) A change involving only physical properties
- Which of the following is a sign of a chemical change?
- A) Change in shape
- B) Change in size
- C) Formation of a precipitate
- D) Dissolution in water
- What happens when iron rusts?
- A) It loses weight
- B) It undergoes a physical change
- C) It combines with oxygen to form a new substance
- D) It retains its original properties
- Which is an example of a chemical reaction?
- A) Boiling of water
- B) Melting of butter
- C) Burning of paper
- D) Slicing of bread
- What is required to start a chemical reaction?
- A) Catalyst
- B) Inhibitor
- C) Accelerator
- D) All of the above
Test Paper 2: Interaction within Ecosystems
- What is an ecosystem?
- A) A community of people
- B) A single organism
- C) Interacting organisms and their environment
- D) A collection of minerals
- Which component is not a part of an ecosystem?
- A) Animals
- B) Plants
- C) Buildings
- D) Weather
- What is the role of producers in an ecosystem?
- A) They consume other organisms
- B) They produce oxygen and food
- C) They decompose dead material
- D) They control the population of species
- Which of the following is an example of a decomposer?
- A) Lion
- B) Mushroom
- C) Grass
- D) Giraffe
- What is a food chain?
- A) A series of restaurants
- B) A process of cooking food
- C) A sequence where organisms eat and are eaten
- D) A system for growing food
Test Paper 3: Separation Techniques – Distillation
- What is distillation used for?
- A) Mixing liquids
- B) Separating mixed liquids based on boiling points
- C) Filtering solids from liquids
- D) Changing the chemical composition of liquids
- In the distillation process, what happens to the liquid with the lower boiling point?
- A) It condenses first
- B) It evaporates first
- C) It remains in the distillation flask
- D) It changes into a solid
- What is the purpose of a condenser in distillation?
- A) To heat the liquid
- B) To mix liquids
- C) To cool down vapor and turn it back into liquid
- D) To separate solids
- Which of the following can be separated by simple distillation?
- A) Salt from water
- B) Alcohol from water
- C) Sand from water
- D) Oil from water
- What is a key requirement for a mixture to be separated by distillation?
- A) High pressure
- B) Different boiling points
- C) Similar boiling points
- D) High viscosity
Test Paper 4: Separation Techniques – Paper Chromatography
- What is the principle behind paper chromatography?
- A) Evaporation
- B) Solubility
- C) Precipitation
- D) Density
- What does the stationary phase refer to in paper chromatography?
- A) The paper
- B) The solvent
- C) The mixture
- D) The atmosphere
- Why is a baseline drawn in pencil in paper chromatography?
- A) Pencil reacts with the solvent
- B) Pencil marks do not dissolve in the solvent
- C) It helps the paper absorb the solvent
- D) It indicates where to place the paper in the solvent
- What determines how far a substance travels in paper chromatography?
- A) Its color
- B) Its solubility in the solvent
- C) Its weight
- D) Its boiling point
- What is the purpose of using a solvent in chromatography?
- A) To draw on the paper
- B) To dissolve the substances in the mixture
- C) To hold the paper upright
- D) To act as a filter
Chemical Changes
- What is the product formed when magnesium reacts with hydrochloric acid?
- Name the type of reaction where two or more substances combine to form a single product.
- What color change indicates the oxidation of iron?
- Which gas is commonly produced in reactions involving acids and carbonates?
- What is the term for a substance that speeds up a chemical reaction without being consumed?
Interaction within Ecosystems
- What type of organism is the primary source of energy in any ecosystem?
- Name the process by which plants convert light energy into chemical energy.
- What is the term used for a graphical representation of the number, biomass, or energy of organisms at each trophic level in an ecosystem?
- What do we call organisms that feed directly on producers?
- Which cycle involves the process of converting atmospheric nitrogen into a usable form for plants?
Separation Techniques – Distillation
- What do you call the device used to cool vapors back into liquid during distillation?
- Name a common laboratory use for distillation.
- What is the main reason why fractional distillation is used instead of simple distillation for crude oil?
- During distillation, what is the term for the liquid that collects after it has been vaporized and condensed?
- What type of distillation would you use to separate components of air?
Separation Techniques – Paper Chromatography
- What is used as the mobile phase in paper chromatography?
- Name the effect that causes the separation of different components in chromatography.
- What should you use to mark the origin line in paper chromatography to ensure it doesn’t interfere with the separation?
- What term describes the ratio between the distance traveled by the solute and the solvent front in chromatography?
- In chromatography, which component travels further on the paper: the one with higher or lower solubility in the solvent?
Chemical Changes
- What substance is formed when a metal reacts with oxygen?
- What is the term for a chemical reaction that absorbs heat from the surroundings?
- Name the type of chemical reaction that involves a substance combining with oxygen to release energy and light.
- Which indicator turns pink in basic solutions and colorless in acidic solutions?
- What type of reaction occurs when an acid and a base neutralize each other to form water and a salt?
Interaction within Ecosystems
- What term is used for animals that only eat plants?
- Name the large-scale geographical ecosystem type characterized by specific types of natural vegetation and climate conditions.
- What is the apex predator in a food chain?
- What term describes organisms that break down dead or decaying organisms, returning essential nutrients to the ecosystem?
- Which natural process removes carbon dioxide from the atmosphere, helping to regulate Earth’s climate?
Separation Techniques – Distillation
- What is the difference between simple and fractional distillation?
- Name the property that primarily determines how substances are separated by distillation.
- In the context of distillation, what is a ‘fraction’?
- What kind of mixtures can be separated by steam distillation?
- What role does a Liebig condenser play in a distillation setup?
Separation Techniques – Paper Chromatography
- How do you calculate the retention factor in paper chromatography?
- What is the stationary phase in gas chromatography called?
- Why must the chromatography paper not touch the sides of the container?
- What safety precaution should you observe when using solvents in chromatography?
- In chromatography, what determines the choice of solvent for the mobile phase?
- What is produced when a base reacts with an acid?
- Name the type of reaction that releases energy in the form of heat.
- What is the new substance called that forms as a result of a chemical reaction?
- Which gas is produced when vinegar reacts with baking soda?
- What term describes the breaking down of a compound into simpler substances by heating?
- What color change is observed when litmus paper is added to an acid?
- Name a common household product that undergoes a chemical change when used for cleaning.
- What is the main sign that a chemical change has occurred during cooking?
- Which element is typically involved in oxidation reactions?
- What is the term for the smallest particle of a compound that has the chemical properties of that compound?
- What type of chemical reaction involves the exchange of ions between two reactants to form new products?
- Name a substance that acts to reduce the activation energy needed to start a chemical reaction.
- Which type of reaction forms water as one of the products when an acid reacts with a metal oxide?
- What happens to the mass of reactants and products in a closed system during a chemical reaction, according to the law of conservation of mass?
- What type of chemical reaction is involved in the process of photosynthesis?
- Name the gas that is a common byproduct when acids react with metals.
- What change occurs to iron when it rusts?
- What type of reaction is a combustion reaction?
- Which substance is formed when sulfur dioxide is added to water?
- What is the name of the chemical process that plants use to make their own food using sunlight?
- What is the pH range of an acid?
- Name a common household alkali.
- What is formed when an acid reacts with a metal?
- Which indicator turns red in acidic solutions and blue in alkaline solutions?
- What type of salt is produced when hydrochloric acid reacts with sodium hydroxide?
- What gas is typically released when an acid reacts with a carbonate?
- Name an acid found in the stomach that helps in digestion.
- What type of solution is formed when an acid is neutralized by a base?
- Which acid is commonly used in car batteries?
- What color does phenolphthalein turn in an alkaline solution?
- What is the product called when an acid reacts with an alkali?
- Which base is used in the treatment of acidic soils?
- Name a naturally occurring acid found in citrus fruits.
- What does the term ‘amphoteric’ mean in relation to a substance?
- Which common laboratory base, when diluted, is often used in first aid for acid burns?
- What property of acids and bases does litmus paper test?
- What is the effect of diluting an acid with water on its pH value?
- Name an industrial use of alkalis.
- What type of reaction occurs when an acid and a base react to form water and a salt?
- Which indicator would you use to perform a titration between an acid and a base?