Chemical Reaction And Equation Quiz!

When balancing a chemical equation, the number of atoms on both sides of the equation must be equal. This is because the law of conservation of mass states that mass can neither be created nor destroyed in a chemical reaction, it can only be rearranged. Balancing the equation ensures that the same number and type of atoms are present on both sides, thus satisfying the law of conservation of mass.

Nitrogen gas is used in the storage of fat and oil-containing foods for a long time. This is because nitrogen is an inert gas, meaning it does not react with the food or cause any chemical changes. By replacing the oxygen in the storage environment with nitrogen, the food is protected from oxidation, which can lead to spoilage. Nitrogen also helps to maintain the freshness and quality of the food by preventing the growth of bacteria and other microorganisms.

The given set-up is used for electrolysis of water. Electrolysis is a process in which an electric current is passed through a substance, causing a chemical reaction to occur. In this case, water is being electrolyzed, which means that the water molecules are being broken down into hydrogen and oxygen gases. This is achieved by passing an electric current through the water using the electrodes shown in the diagram. The hydrogen gas is collected at the cathode (negative electrode), while the oxygen gas is collected at the anode (positive electrode).

When sulphuric acid reacts with barium chloride solution, it forms white precipitates of barium sulphate. This is because sulphuric acid reacts with barium chloride to produce barium sulphate as a solid product. The formation of white precipitates confirms the presence of barium sulphate in the reaction.

When a magnesium ribbon is burnt in the air, it undergoes a chemical reaction with oxygen to form magnesium oxide. Magnesium oxide is a white powdery substance, which is the ash formed when magnesium burns. Therefore, the correct answer is white.

The given reaction involves the displacement of copper from copper chloride by lead. This is evident from the fact that lead (Pb) replaces copper (Cu) in the reaction, forming lead chloride (PbCl2) and leaving behind copper. Therefore, the correct answer is displacement.

Silver chloride is stored in a dark-colored bottle to avoid the action of sunlight. Sunlight can cause the decomposition of silver chloride, leading to the formation of silver metal and chlorine gas. By storing it in a dark-colored bottle, the entry of sunlight is restricted, minimizing the decomposition reaction and preserving the integrity of the silver chloride.

Gold does not corrode when exposed to the atmosphere because it is a highly unreactive metal. It is resistant to oxidation and does not easily react with oxygen or moisture in the air. This property makes gold highly valuable and desirable for use in jewelry and other applications where durability and resistance to corrosion are important.

Rancidity refers to the spoilage of food due to the oxidation of fats. Adding antioxidants helps prevent rancidity by inhibiting the oxidation process. Storing food away from light is also important as light exposure can accelerate the oxidation process. Keeping food in the refrigerator slows down the rate of oxidation by reducing the temperature and inhibiting the growth of microorganisms. Therefore, all of these methods contribute to preventing rancidity.

When calcium carbonate (CaCO3) is heated, it decomposes into calcium oxide (CaO) and carbon dioxide (CO2) gas. The colorless gas that comes out during the heating process is the carbon dioxide gas. Therefore, the reaction described in the question is a decomposition reaction, where a compound breaks down into simpler substances.

Fatty food becomes rancid due to the process of oxidation. Oxidation occurs when the fats in the food react with oxygen in the air, causing them to break down and produce unpleasant odors and flavors. This process is accelerated by factors such as heat, light, and exposure to air. As a result, the food becomes rancid and unfit for consumption.

In the given equation, Cu reacts with HNO3 to form Cu(NO3)2, NO2, and H2O. The balanced equation shows that for every 1 mole of Cu, 4 moles of HNO3 are required. This indicates that x (the coefficient of HNO3) must be 4. Additionally, the equation shows that for every 1 mole of Cu, 2 moles of NO2 are produced. Therefore, y (the coefficient of NO2) must be 2. Hence, the values of x and y are 4 and 2, respectively.

The respiration process described in the question involves the combustion of glucose, a chemical reaction that releases energy. This energy is produced by combining glucose with oxygen in the cells of our body. Since this process releases energy in the form of heat, it is classified as an exothermic process.

Potassium (K) is the most reactive metal among the options given. It belongs to Group 1 of the periodic table, also known as the alkali metals. These metals are highly reactive because they have only one electron in their outermost shell, which they readily lose to form a positive ion. Potassium reacts vigorously with water, releasing hydrogen gas and forming a strong alkaline solution. It also reacts with oxygen in the air, forming a white oxide layer. This reactivity is due to the low ionization energy and high electropositivity of potassium.

Both CO2 and H2 gases are colourless because they do not have any pigments or dyes that would give them a distinct color. Color is determined by the absorption and reflection of light, and since these gases do not interact with light in a way that produces color, they appear colorless to the human eye.

The given chemical reaction is classified as a redox reaction because there is a transfer of electrons between the reactants. Additionally, it is also classified as a displacement reaction because one element is replaced by another element in the reaction. Therefore, the correct answer is "Redox reaction as well as displacement reaction."

When iron (Fe) is exposed to moist air, it undergoes a chemical reaction with oxygen (O2) to form a reddish-brown compound called iron(II) oxide (Fe2O2). This compound is commonly known as rust. Therefore, the element X is Fe and the compound Y is Fe2O2.

Burning of L.P.G. will result in the evolution of heat energy because it is a combustion reaction. When L.P.G. (liquefied petroleum gas) is burned, it reacts with oxygen in the air to produce carbon dioxide and water vapor, releasing a large amount of heat energy in the process. This is an exothermic reaction where energy is released in the form of heat.

The process of melting candle wax when heated does not involve a chemical reaction. Melting is a physical change where the wax changes from a solid to a liquid state due to the application of heat. No new substances are formed during this process. In contrast, burning of candle wax involves a chemical reaction called combustion, where the wax reacts with oxygen in the air to produce heat, light, carbon dioxide, and water vapor. Digestion of food in our stomach and ripening of banana also involve chemical reactions as they involve the breakdown of complex molecules into simpler ones.

A reducing agent is a substance that undergoes oxidation by losing electrons, causing another substance to be reduced by gaining those electrons. In other words, it donates electrons to another substance, resulting in the reduction of that substance. This process is important in many chemical reactions, as it allows for the transfer of electrons and the conversion of one substance into another. Therefore, a substance that oxidizes itself and reduces others is known as a reducing agent.

In a neutralization reaction, an acid reacts with a base to form a salt and water. This reaction involves the exchange of ions between the acid and the base, resulting in the formation of a new compound. This process is known as a double displacement reaction, as the positive ions from the acid combine with the negative ions from the base to form the salt. Therefore, the correct answer is double displacement reaction.

A double displacement reaction is a type of chemical reaction where two compounds exchange their ions to form two new compounds. In this reaction, the positive ions of one compound combine with the negative ions of the other compound, and vice versa. This results in the formation of two new compounds with different combinations of ions. Double displacement reactions often occur in aqueous solutions and are characterized by the formation of a precipitate, gas, or water.

When magnesium is exposed to air, it rapidly reacts with oxygen to form a layer of magnesium oxide on its surface. This layer of oxide can hinder the combustion process when the ribbon is burned. By rubbing the ribbon with sandpaper, the layer of magnesium oxide is physically removed, exposing a fresh surface of magnesium that can react more readily with oxygen during combustion. This allows for a more efficient and complete burning of the magnesium ribbon.

Aluminium dust is the correct answer because it can undergo a displacement reaction with iron (III) oxide to produce iron and aluminium oxide. This reaction releases a large amount of heat, making it suitable for welding rail tracks. Copper granules, magnesium ribbon, and sodium pellets do not have the ability to displace iron from its oxide, so they would not be suitable for this purpose.

A chemical reaction involves the formation of new substances with different properties, the breaking and formation of chemical bonds, and the rearrangement of atoms to form new products. However, it does not involve changing the atoms of one element into those of another element to form new products. This process is known as nuclear transmutation, which is not a part of a chemical reaction.

When ferrous sulfate is heated strongly, it undergoes decomposition to form ferric oxide as the main product. The change in color from green to brown is observed during this reaction. This change in color is due to the conversion of the green ferrous sulfate into brown ferric oxide.

When a copper rod is dipped in an iron sulfate solution, no reaction takes place. This is because copper is less reactive than iron, so it cannot displace iron from its compound. Additionally, there is no change in color observed in the solution, indicating that there is no chemical reaction occurring. Lastly, there is no mention of any heat being released, suggesting that the reaction is not exothermic. Therefore, the correct answer is that no reaction takes place.

In this redox reaction, hydrogen sulfide is oxidized to sulfur, which means it loses electrons and is the reducing agent. Iodine is reduced to hydrogen iodide, which means it gains electrons and is the oxidizing agent. Therefore, the correct answer is "Iodine and hydrogen sulphide respectively".

Rust is a reddish-brown substance that forms on iron or steel when it reacts with oxygen and water. It is a compound known as iron oxide, specifically ferric oxide. The term "hydrated" indicates that water molecules are also present in the compound. Therefore, the correct answer is "Hydrated ferric oxide."

The reaction of H2 gas with oxygen gas to form water is an example of a combination reaction because two substances are combining to form a single product. It is also a redox reaction because there is a transfer of electrons between the reactants. Additionally, it is an exothermic reaction because it releases heat energy. Therefore, the correct answer is "All of these reactions" as the given reaction exhibits characteristics of all three types of reactions.