alleryStart learning →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_
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