The correct option is (C): Coke (C) converts \(CO _2\) to \(CO\).
Option (C) states that coke (\( \text{C} \)) converts carbon dioxide (\( \text{CO}_2 \)) to carbon monoxide (\( \text{CO} \)) in the blast furnace. This is indeed correct.
The overall reaction for this process is:
\[ \text{CO}_2 + \text{C} \rightarrow 2\text{CO} \]
This reaction occurs at high temperatures in the blast furnace, typically in the range of 900 K to 1500 K. It is an important step in the extraction of iron from its ore because carbon monoxide is a reducing agent that reacts with iron ore (\( \text{Fe}_2\text{O}_3 \)) to produce iron metal (\( \text{Fe} \)):
\[ \text{Fe}_2\text{O}_3 + 3\text{CO} \rightarrow 2\text{Fe} + 3\text{CO}_2 \]
Thus, option (C) accurately describes one of the key processes involved in the extraction of iron from its ore in the blast furnace.
A block of mass 1 kg is pushed up a surface inclined to horizontal at an angle of \( 60^\circ \) by a force of 10 N parallel to the inclined surface. When the block is pushed up by 10 m along the inclined surface, the work done against frictional force is:
[Given: \( g = 10 \) m/s\( ^2 \), \( \mu_s = 0.1 \)]
A gas can be taken from A to B via two different processes ACB and ADB. When path ACB is used, \( 60 J \) of heat flows into the system and \( 30 J \) of work is done by the system. If path ADB is used, the work done by the system is \( 10 J \). The heat flow into the system in path ADB is:
Two identical concave mirrors each of focal length $ f $ are facing each other as shown. A glass slab of thickness $ t $ and refractive index $ n_0 $ is placed equidistant from both mirrors on the principal axis. A monochromatic point source $ S $ is placed at the center of the slab. For the image to be formed on $ S $ itself, which of the following distances between the two mirrors is/are correct:
Minerals are the naturally occurring, homogeneous inorganic solid substances. They are having a definite chemical composition and crystalline structure, hardness and color. For example, copper pyrite, calamine, etc.
Impurities in an ore are called gauge. The removal of a gauge from the ore is called concentration ore.
Several steps are involved in the extraction of pure metal from ores. Major steps are as follows –