$解：氢氧化钠的质量为：$
$80.0g×20\%=16.0g，$
$设参加反应的H_{2}SO_{4}的质量为x，$
$H_{2}SO_{4}+2NaOH\xlongequal[\\]{\\}Na_{2}SO_{4}+2H_{2}O$
$98~~~~~~~~~~~~~~~~~80$
$x~~~~~~~~~~~~~~~~~~~16.0g$
$\frac {98}{80}=\frac {x}{16.0g}，$
$解得x=19.6g。$
$答：这一定量的石油产品中含有H_{2}SO_{4}的质量为19.6g。$
