Chemistry in Class 10 : Practice MCQ Questions & Answers with Explanations

A catalyst speeds up a chemical reaction by lowering the activation energy without being consumed in the process. Catalysts are vital in industrial processes such as the production of fertilizers.

Sodium reacts vigorously with water to produce hydrogen gas and sodium hydroxide, a characteristic reaction of alkali metals.

Sodium hydroxide (NaOH), also known as caustic soda, is commonly used in cleaning products due to its ability to break down grease and other contaminants.

A decomposition reaction involves the breakdown of a compound into two or more simpler substances, often requiring heat or light. An example is calcium carbonate breaking down into calcium oxide and carbon dioxide.

Diamond is an allotrope of carbon where carbon atoms are arranged in a crystal lattice, making it the hardest natural substance. Other allotropes include graphite and graphene.

When vinegar (acetic acid) reacts with baking soda (sodium bicarbonate), carbon dioxide gas is produced. This reaction is commonly used in science experiments and as a cleaning agent.

Carbon monoxide is a colorless, odorless, and poisonous gas formed during the incomplete combustion of carbon-containing materials. It can be deadly when inhaled in large amounts.

Graphite is an excellent conductor of electricity because it has free electrons that move between layers of carbon atoms. This makes it useful in pencils and electrical applications.

Alcohols contain the hydroxyl group (-OH) as their functional group. This group makes alcohols soluble in water and gives them their characteristic properties.

Glucose is an organic compound because it contains carbon atoms bonded with hydrogen and oxygen, which are typical features of organic molecules.

Methane is a saturated hydrocarbon where all carbon atoms are connected by single bonds, making it less reactive than unsaturated hydrocarbons like ethene and ethyne.

The litmus test determines whether a substance is acidic or basic. Red litmus turns blue in a basic solution, and blue litmus turns red in an acidic solution.

Methane ($CH_4$) is a simple hydrocarbon consisting of one carbon atom bonded to four hydrogen atoms. It is the main component of natural gas.

Nitrogen is widely used in the production of fertilizers due to its essential role in plant growth. It is a key component of compounds like ammonium nitrate and urea.

Iron is a metal with properties like high conductivity and malleability. It is commonly used in construction and manufacturing.

When a fuel burns in oxygen, the products of combustion are typically water and carbon dioxide. This chemical reaction releases energy in the form of heat and light.

Hydrogen peroxide is represented by the formula $H_2O_2$. It consists of two hydrogen atoms and two oxygen atoms, and is commonly used as a disinfectant and bleaching agent.

Metals are ductile (can be drawn into wires) and malleable (can be hammered into thin sheets). These properties arise from the atomic arrangement that allows shape changes without breaking.

Calcium oxide is commonly known as quicklime. It is a white, caustic substance used in the production of cement and as a drying agent in various industrial processes.

Acids release hydrogen ions (H+) when dissolved in water. This gives them their characteristic properties, such as sour taste and the ability to turn litmus paper red.