In laboratory preparation of hydrogen what are the mistake in the arrangement correct the figure

Balance the following reaction. as2s3 + 9o2 → 2as2o3 + so2

The polarity of an oxygen-hydrogen bond is higher than the polarity of a nitrogen-hydrogen bond, allowing amines to be more soluble than alcohols.

Which number should be placed before f2 on the reactants side equation to make equation balanced? xe + > xef4