The balanced chemical formula should be Al2(SO4)3 + 6NaOH = 2Al(OH)3 + 3Na2SO4
Therefore the coefficient of Al(OH)3 is 2!
Hope that helps :)
A. They speed up chemical reactions
<span>Percent yield is the measured recovery of a substance in grams divided by the theoretical amount of substance expected in grams (times 100 to convert to %). Undissolved Aluminum trihydroxide would add mass to the Aluminum sulphate one is making here. The measured mass would be inaccurately high, increasing the percent yield calculated.</span>