Why is the extraction of copper from pyrites more difficult than that from its oxide ore through reduction?

Why Zinc not extracted from Zinc oxide through reduction using CO?

Describe the role of SiO_2 in the extraction of Copper from Copper matte.

What is the chief ore of iron? Write chemical reactions taking place is the extraction of iron from its ore?

Describe the role of NaCN in the extraction of gold from gold ore.

How copper is extracted from low grade ore?

Iron ores are separated from its impurities by-

What chemical principle is involved in choosing a reducing agent for getting the metal from its oxide ore? Consider the metal oxide Al_2O_3 and Fe_2O_3 and Justifuy the choice of the reducing agent.

Actinoid contraction is greater from element to element than lanthanoid contraction. Why?

A car starts from rest on a half kilometer bridge. The co-efficient of friction between the tyres and road is 1. Show that one can't drive through the bridge in less than 10 sec.

An infinitely long straight current carrying wire produces a magnetic field B at a point at a distance 'a' from it. What must be the radius of the circular loop, so that for the same current through it the magnetic field at (i) its dentre equals B/2