Question

which of the following equations is balanced?
a $h_{2}+2o_{2}\to 2h_{2}o$
b $h_{2}+o_{2}\to h_{2}o$
c $2h_{2}+o_{2}\to h_{2}o$
d $2h_{2}+o_{2}\to 2h_{2}o$
check ii

Explanation:

Step1: Check hydrogen atoms

For option a: Left - hand side has \(2\) H atoms (from \(H_2\)) and right - hand side has \(2\times2 = 4\) H atoms (from \(2H_2O\)). Not balanced.
For option b: Left - hand side has \(2\) H atoms (from \(H_2\)) and right - hand side has \(2\) H atoms (from \(H_2O\)). Left - hand side has \(2\) O atoms (from \(O_2\)) and right - hand side has \(1\) O atom (from \(H_2O\)). Not balanced.
For option c: Left - hand side has \(2\times2=4\) H atoms (from \(2H_2\)) and right - hand side has \(2\) H atoms (from \(H_2O\)). Not balanced.
For option d: Left - hand side: \(2\times2 = 4\) H atoms (from \(2H_2\)) and \(2\) O atoms (from \(O_2\)). Right - hand side: \(2\times2=4\) H atoms (from \(2H_2O\)) and \(2\times1 = 2\) O atoms (from \(2H_2O\)). Balanced.

Answer:

d. \(2H_2+O_2
ightarrow2H_2O\)