Chemical Reactions

Concept: The ability of a metal to displace hydrogen from an acid (like dilute HCl) depends on its position in the reactivity series (also known as the activity series of metals). Metals above hydrogen in the reactivity series are more reactive than hydrogen and can displace it from dilute non-oxidizing acids. Step 1: Understanding the Reactivity Series The reactivity series arranges metals in order of their decreasing reactivity. A simplified portion relevant here is: K>Na>Ca>Mg>Al>Zn>Fe>Sn>Pb>(H)>Cu>Hg>Ag>Pt>Au (Highly reactive Least reactive) Metals {above} Hydrogen (H) in this series will displace hydrogen from dilute acids like HCl or . Metals {below} Hydrogen will not displace hydrogen from these acids. Step 2: Analyzing the options based on their position relative to Hydrogen % Option (R) (1) Ag (Silver): Silver is {below} hydrogen in the reactivity series. Therefore, it cannot displace hydrogen from dilute HCl. (Reaction: ) % Option (S) (2) Au (Gold): Gold is far {below} hydrogen in the reactivity series (it's a very unreactive noble metal). It cannot displace hydrogen from dilute HCl. (Reaction: ) % Option (T) (3) Mg (Magnesium): Magnesium is well {above} hydrogen in the reactivity series. Therefore, it is more reactive than hydrogen and will displace it from dilute HCl. Reaction: % Option (U) (4) Cu (Copper): Copper is {below} hydrogen in the reactivity series. Therefore, it cannot displace hydrogen from dilute HCl. (Reaction: ) Step 3: Identifying the correct metal Magnesium (Mg) is the only metal among the options that is more reactive than hydrogen and thus will displace hydrogen from dilute HCl.

Step 1: Identify the reactants.
The reactants are dilute hydrochloric acid (HCl) and granulated zinc (Zn). Zinc is a metal, and hydrochloric acid is a strong acid. Step 2: Recall the reaction of metals with acids.
When a reactive metal reacts with a dilute acid, it typically displaces hydrogen from the acid to form a salt and hydrogen gas. The reactivity series of metals helps determine if a metal will react with an acid. Zinc is more reactive than hydrogen, so it will displace hydrogen from HCl. Step 3: Write the chemical reaction.
The reaction between zinc and hydrochloric acid is a single displacement reaction: Zn(s) + 2HCl(aq) ZnCl (aq) + H (g)
Zinc (Zn) reacts with hydrochloric acid (HCl).
Zinc chloride (ZnCl ) is formed as the salt.
Hydrogen gas (H ) is released. Step 4: Evaluate the given options.
(1) 'H ' gas and 'ZnCl ' are Produced: This matches the predicted products of the reaction.
(2) No Reaction Produced: This is incorrect as zinc is more reactive than hydrogen.
(3) 'H O' and 'ZnO' are Produced: This is incorrect. ZnO would be produced if zinc reacted with oxygen, and H O is not a primary product of this type of displacement reaction.
(4) H O and ZnSO are Produced: This is incorrect. ZnSO (zinc sulfate) would be formed if zinc reacted with sulfuric acid, not hydrochloric acid. Step 5: Conclude the correct products.
When dilute HCl is added to granulated Zn, hydrogen gas and zinc chloride are produced. $ _2 _2 $