Chemical Reactions And Equations... I

When a metal reacts with an acid, hydrogen gas is evolved. This is because the acid reacts with the metal to form metal salt and hydrogen gas. The reaction can be represented by the general equation: Metal + Acid → Metal Salt + Hydrogen gas. Hydrogen gas is released as a byproduct of the reaction and can be observed as bubbles or effervescence.

In this reaction, iron (Fe) reacts with copper sulfate (CuSO4) to form iron sulfate (FeSO4) and copper (Cu). This is a single displacement reaction, where the more reactive metal (iron) replaces the less reactive metal (copper) in the compound.

When magnesium burns in air, it reacts with oxygen to form magnesium oxide. During this reaction, a bright and intense white flame is produced. This is because the energy released during the reaction excites the electrons in the magnesium atoms, causing them to emit light in the visible spectrum, which appears as a dazzling white flame.

According to the law of conservation of mass, the total mass of the reactant is equal to the total mass of the product. This means that during a chemical reaction, the mass of the reactants before the reaction is equal to the mass of the products after the reaction. This law states that matter cannot be created or destroyed in a chemical reaction, only rearranged. Therefore, the total mass of the reactant must be equal to the total mass of the product.

A chemical equation is a short-hand method of representing a chemical reaction. It consists of reactants on the left side, separated by a plus sign, and products on the right side, separated by an arrow. The equation also includes coefficients to represent the number of molecules or moles involved in the reaction. This notation allows chemists to easily understand and communicate the details of a chemical reaction. Balanced equation and skeletal equation are also types of chemical equations, but the term "chemical equation" is a more general term that encompasses all types of equations used to represent chemical reactions.

The correct answer is NH4 OH. Ammonium hydroxide is a compound made up of ammonium (NH4+) and hydroxide (OH-) ions. The chemical formula NH4 OH represents the combination of these ions. The other options, NH3OH, NaOH, and NaHCO3, do not represent the correct formula for ammonium hydroxide.

When aqueous solutions of Barium chloride and Sodium sulphate react together, a white precipitate is formed. This is because Barium chloride and Sodium sulphate react to form Barium sulphate, which is insoluble in water and appears as a white solid precipitate.

Carbon has an atomic number of 6, which means it has 6 electrons. In its ground state, carbon has 2 electrons in its innermost shell and 4 electrons in its outermost shell. The valency of an element is determined by the number of electrons it needs to gain, lose, or share to achieve a stable electron configuration. Since carbon has 4 electrons in its outermost shell, it needs to gain, lose, or share 4 electrons to achieve stability. Therefore, the valency of carbon is 4.

Magnesium oxide is a basic compound. It is formed by the reaction of magnesium with oxygen. When dissolved in water, it forms magnesium hydroxide, which is a strong base. This compound can also neutralize acids, indicating its basic nature. Therefore, the correct answer is basic.

Calcium Oxide is commonly known as Quick lime, while Calcium hydroxide is referred to as Slaked lime.