Metallurgy, Metals, Non-Metals & Alloy RRB PYQ

Navin performed a displacement reaction by adding a magnesium strip to an aqueous solution of CuSO4. Magnesium, being higher in the reactivity series, displaces copper from copper sulfate to form magnesium sulfate. Other metals like platinum, copper, and silver are less reactive than copper and cannot displace it in similar reactions.

Chlorine gas reacts with potassium iodide solution in a displacement reaction, where chlorine displaces iodine from the solution to form potassium chloride and iodine. In displacement reactions, one element replaces another in a compound based on reactivity.

Corrosion particularly affects iron (Fe), resulting in rust formation through an oxidation reaction when exposed to moisture and oxygen. This process involves the creation of iron oxide, commonly known as rust, which weakens the metal over time. Preventive methods like painting and galvanizing are often used to protect iron and steel structures from corrosion.

The reaction between zinc metal and copper sulphate solution is a classic example of a single displacement reaction. Statement (i) is True: Since zinc is more reactive than copper (higher in the reactivity series), it displaces copper from its salt solution. Chemical Equation: Zn(s) + CuSO4(aq) → ZnSO4(aq) + Cu(s).

In the process of galvanization, iron is coated with a layer of zinc to protect it from rusting. This is achieved by dipping the iron in molten zinc. Zinc forms a barrier that prevents air and moisture from coming into contact with the iron, thus preventing rust formation.

When zinc is added to a solution of copper sulphate, copper is displaced. This is because zinc is more reactive than copper and can replace copper in the solution. The chemical reaction is: Zn(x) + CuSO4(aq) → ZnSO4(aq) + Cu(s). In this displacement reaction, zinc displaces copper from copper sulphate, forming zinc sulphate and solid copper.

This order reflects the decreasing reactivity of the metals, with Potassium (K) and Sodium (Na) being highly reactive alkali metals, followed by Zinc (Zn), a moderately reactive transition metal. Copper (Cu), Mercury (Hg), and Silver (Ag) are less reactive metals. The reactivity series helps in predicting the outcomes of reactions, such as displacement reactions and metal extractions.

'All metals (except Mercury) are in liquid form and are soft' is incorrect because, in reality, most metals are solid at room temperature and have varying degrees of hardness. While mercury is indeed the only metal in liquid form at room temperature, metals like iron, copper, and aluminum are generally hard. Additionally, metals are shiny, malleable, and ductile, with high melting and boiling points.

Aluminium, iron and zinc do not react with cold water. Aluminium forms a strong aluminium oxide layer on its surface, which prevents water from coming into direct contact with the metal. Iron and zinc are less reactive metals compared to sodium or calcium. Their reaction with water is very slow and requires higher temperatures (like steam) to proceed. Metals sodium, calcium and potassium have a vigorous reaction with cold water to form metal hydroxides and hydrogen gas.

Ag > Al > Na > Zn. Metals are shiny in appearance. Solid metals are good conductors of electricity. Metals are strong and hard. Metals are malleable and ductile.