Physical and Chemical Changes

When fuel is burned, it undergoes a combustion reaction producing carbon dioxide gas as a byproduct.

The burning of wood is a chemical change because it results in the formation of new substances like ash and smoke.

Oil can change into fat through the process of hydrogenation, which involves adding hydrogen to unsaturated fats.

Fertilizers are used to fulfill the nutritional requirements of plants, providing essential nutrients like nitrogen, phosphorus, and potassium.

Melting of ice cream is a physical change because it involves a change in state from solid to liquid without altering the chemical composition.

Chemical changes are usually irreversible because they result in the formation of new substances with different chemical properties.

Mixing sugar in water is an example of a physical change because it involves the dissolution of sugar without altering its chemical structure.

Melting of wax is a physical change because it involves a change in state from solid to liquid without altering its chemical composition.

Physical changes are mostly reversible because they do not alter the chemical composition of the substance, allowing it to return to its original state.

Melting of ice is a physical change because it involves a change in state from solid to liquid without altering its chemical composition.

A chemical change alters the chemical composition of a substance, resulting in the formation of new substances with different properties.

The process used to convert vegetable oil into banaspati ghee is hydrogenation, which involves adding hydrogen to unsaturated fats.

Nickel is used as a catalyst in the hydrogenation of vegetable oil to facilitate the addition of hydrogen to the oil molecules.

Plastics are made up of many small molecules called monomers, which link together to form polymers.

Plastics are also called polymers due to their large molecule size, consisting of repeating structural units.

Banaspati ghee is a product of a chemical change, specifically through the hydrogenation process of vegetable oils.

The release of gas often indicates a chemical change, as it suggests a chemical reaction resulting in the formation of new gaseous substances.

A physical change is best defined by the fact that no new substance is formed; only the physical properties of a substance are altered.

Photosynthesis in plants is an example of a chemical change because it involves the conversion of carbon dioxide and water into glucose and oxygen.

The burning of a candle is both a physical and chemical change. The melting of wax is physical, while the combustion of wax is chemical.

Melting of chocolate is a reversible change because it can be melted and then solidified again without altering its chemical composition.

A chemical change always results in the formation of a new substance with different chemical properties.

Rusting of iron is an example of a permanent and chemical change because it results in the formation of a new substance (iron oxide) with different properties.

In a physical change, the identity of the substance remains the same; only its physical properties, such as state or shape, are altered.

Drying of wet clothes is a physical change because it involves the evaporation of water without altering the chemical composition of the clothes.

Acid rain is caused by gases from vehicles and factories, which release pollutants like sulfur dioxide and nitrogen oxides into the atmosphere.

Hydrocarbons are made of hydrogen and carbon atoms.

Methane is a hydrocarbon fuel commonly used in homes for heating and cooking.

Burning of diesel or petrol is an example of a chemical change because it involves combustion reactions that produce new substances.

Fossil fuels are non-renewable energy sources because they take millions of years to form and cannot be replenished on a human timescale.

Fertilizers provide essential nutrients to plants, such as nitrogen, phosphorus, and potassium, which are crucial for plant growth.

Helium is not typically a part of fertilizers. Fertilizers usually contain elements like nitrogen, phosphorus, and potassium.

Ammonium Nitrate has the chemical formula NH₄NO₃, which is commonly used as a fertilizer.

Hydrogenation is used for turning oil into ghee by adding hydrogen to unsaturated fats in the presence of a catalyst.

In the hydrogenation process, hydrogen gas is passed through vegetable oil to convert it into a more saturated fat like ghee.

Nickel acts as a catalyst in the hydrogenation process, facilitating the addition of hydrogen to the vegetable oil without being consumed in the reaction.

Plastics are made of polymers, which are large molecules composed of repeating structural units called monomers.

Monomers are small repeating units that combine to form polymers, which are the building blocks of plastics.

Plastics are not easily biodegradable, which is one of their major environmental drawbacks.