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Science (086) — AI-generated practice question

AI-generated practice question — model-generated for extra practice, not a previous-year CBSE board question.

Q1. [1] straightforward initial-understanding
When lead nitrate is heated strongly, brown fumes are produced along with a solid residue and oxygen gas. What are the brown fumes, and what is the solid residue formed?
Generated by claude-sonnet-4-6 · 2026-06-26 00:53 · grounding rag
Model Answer

The brown fumes are nitrogen dioxide (NO₂). The solid residue formed is lead oxide (PbO).

Explanation

The reaction is: $2\text{Pb(NO}_3)_2 \xrightarrow{\Delta} 2\text{PbO} + 4\text{NO}_2 + \text{O}_2$. Examiners expect both products named correctly. One mark is typically split: ½ for NO₂, ½ for PbO — so both must be stated.

Source: Chapter 1, Section 1.2.2 (Activity 1.6)

Previous-year CBSE Grade 10 board exam questions, organised by subject and chapter, each with a model answer — free to read and print.