The question asks about the gas commonly produced at the anode in primary cells. This requires understanding the basic electrochemistry of primary cells, specifically the oxidation reactions occurring at the anode.
Correct Option: C) Hydrogen is commonly produced at the anode in primary cells, often as a side reaction due to the reaction of the anode material (like zinc) with the acidic electrolyte, leading to self-discharge.
The question asks to identify the most common type of primary battery used in households. This requires knowledge of common battery types and their applications.
Correct Option: B) Alkaline batteries are the most common type of primary battery found in household use. They are widely available in various sizes (AA, AAA, C, D) and power many everyday devices like remote controls, clocks, and toys.
The question asks to identify an environmentally friendly primary cell among the given options. This requires knowledge of the chemical composition and environmental impact of common battery types.
A) Lithium primary cell — Lithium primary cells are generally considered more environmentally friendly because they do not contain highly toxic heavy metals such as cadmium or lead. While proper disposal and recycling are still important, their chemical composition is less harmful than the alternatives listed.
The question asks about the anode material in a lithium primary cell. A primary cell is a non-rechargeable battery. We need to identify which of the given options serves as the anode (negative electrode) in such a cell, considering the nature of lithium batteries.
B) Lithium — In a lithium primary cell, metallic lithium serves as the anode. It undergoes oxidation during discharge, releasing electrons and forming lithium ions. This is fundamental to the operation and naming of lithium batteries.
The question asks about the typical shelf life of an alkaline battery. This is a factual recall question related to common battery types. We need to identify the standard duration for which an unused alkaline battery can retain its charge.
Correct Option: B) 5-10 years
Modern alkaline batteries are designed to have a long shelf life, typically ranging from 5 to 10 years, sometimes even longer for specific brands or types, when stored properly at room temperature. This is due to low self-discharge rates and improved construction.
The question asks where primary cells are typically NOT used. Primary cells are non-rechargeable batteries, meaning they are designed for single use and then discarded. We need to identify an application that requires frequent or high-power energy supply, making non-rechargeable batteries impractical or uneconomical.
B) Electric vehicles. Electric vehicles require a large amount of energy to power their motors and must be rechargeable for practical and economic reasons. Using primary (non-rechargeable) cells would be prohibitively expensive, impractical due to the sheer number of batteries needed, and environmentally unsustainable, as they would need constant replacement.