How many grams of hydrogen are in 85.0 g of Ca(OH)2

2.30 grams

Explanation: First find how many moles you have:

The molar masses are taken from the periodic table: Ca is 40, O is 16, H is 1. There are two O and 2 H from (OH)2 40+32+2=74 g/mol. Grams (given) x mol/grams (molar mass) = mols, so 85 grams x 1 mol / 74 grams = 1.149 mol. For every mol of Ca(OH)2, there is 2 mol of H so x2 = 2.297 mol H. For every mol of H, there is one gram so 2.297 grams. Rounded to three significant figures you get 2.30 grams.

fire could start, buildings collapsing, and ash falling from the sky.

explanation:

this is because the buildings or plants could catch on fire and the buildings would most likely collapse. lastly ash would fall because all the burning would cause ash to fall from the sky.

hope this .