Home › Karnataka SSLC (Class 10) › Science › Chemical Reactions and Equations › In the balanced equation $3Fe + 4H_2O \rightarro…
In the balanced equation $3Fe + 4H_2O \rightarrow Fe_3O_4 + xH_2$, the value of $x$ is
A4
B2
C3
D6
Answer & Solution
Correct answer: A. 4
1. Balance hydrogen: the right side needs as many H atoms as $4H_2O$ (8 H).
2. So $xH_2$ must give 8 H atoms, i.e. $x = 4$.
3. The balanced equation is $3Fe + 4H_2O \rightarrow Fe_3O_4 + 4H_2$.
_Source: Karnataka SSLC (KSEEB) Class 10 Science, Ch1 'Chemical Reactions and Equations', §1.1.2_
Related questions
A reducing agent in a redox reaction is the substance thatRespiration, in which glucose combines with oxygen to release energy, is best described asThe decomposition of water into hydrogen and oxygen on passing electric current is calledThe unpleasant smell and taste developed in oily foods left exposed for long is calledThe development of a black coating on silver articles left in air is an example ofIn the reaction $CuO + H_2 \rightarrow Cu + H_2O$, the substance that is reduced isIn a chemical reaction, the gain of oxygen by a substance is calledThe reaction $Na_2SO_4 + BaCl_2 \rightarrow BaSO_4\downarrow + 2NaCl$, forming an insolubl