Chemical Reactions And Equation Class 10th

The correct answer is "Rancidity". When oily food such as potato chips is flushed with nitrogen in a packet, it helps to prevent rancidity. Rancidity is the process of the food becoming stale or developing a bad taste and odor due to the oxidation of fats present in the food. By flushing the packet with nitrogen, the oxygen content is reduced, which slows down the oxidation process and helps to maintain the freshness and quality of the food.

In a double displacement reaction, the positive and negative ions of two compounds switch places to form two new compounds. In this case, when barium chloride (BaCl2) and sodium sulphate (Na2SO4) are mixed together, a double displacement reaction occurs. The positive ions (Ba2+ and Na+) switch places with the negative ions (Cl- and SO4 2-), resulting in the formation of barium sulphate (BaSO4) and sodium chloride (NaCl). The white insoluble substances obtained in the reaction indicate the formation of the insoluble compound barium sulphate.

When silver chloride powder is exposed to sunlight, it undergoes a chemical reaction and turns grey. This is because silver chloride is photosensitive, meaning it reacts with light. The reaction causes the silver chloride to decompose and form silver metal and chlorine gas. The silver metal appears grey in color, hence giving the silver chloride powder a grey color when exposed to sunlight.

When iron reacts with copper sulphate solution, iron displaces copper from the copper sulphate solution to form iron sulphate and copper. This type of reaction, where one element displaces another element from a compound, is called a displacement reaction. Therefore, the given reaction is an example of a displacement reaction.

When quick lime reacts with water, it undergoes a highly exothermic reaction. This means that heat is released during the reaction. The reaction between quick lime (calcium oxide) and water produces calcium hydroxide, and this process is known as slaking. The release of heat energy is a characteristic of exothermic reactions, where the products have lower energy than the reactants.

When magnesium ribbon burns, it reacts with oxygen in the air to form magnesium oxide. In this reaction, magnesium loses electrons and oxygen gains electrons. This transfer of electrons indicates a loss of electrons by magnesium, which is characteristic of oxidation. Therefore, burning of magnesium ribbon is an example of oxidation.

During electrolysis of water, water molecules (H2O) are broken down into hydrogen gas (H2) and oxygen gas (O2). The ratio of the volume of hydrogen gas to the volume of oxygen gas produced is 2:1. This means that for every 2 volumes of hydrogen gas produced, 1 volume of oxygen gas is produced.

When ferrous sulphate crystals are heated, they undergo a chemical reaction that releases a gas. This gas is called sulphur dioxide.

Nitrogen dioxide is the correct answer because it is a reddish-brown gas that is formed when nitrogen monoxide reacts with oxygen in the air. The figure likely shows a reddish-brown gas being evolved, indicating the presence of nitrogen dioxide. Nitrogen oxide is a general term that can refer to various nitrogen-oxygen compounds, so it is not as specific as nitrogen dioxide. Nitrogen and ammonia are different compounds and would not be the correct answer in this context.

Respiration is an example of exothermic because it is a process that releases energy in the form of heat. During respiration, organic molecules such as glucose are broken down in the presence of oxygen to produce carbon dioxide, water, and energy in the form of ATP. This energy release is accompanied by the generation of heat, making respiration an exothermic process.