Answer:
a molecule is the <u>smallest</u> particle of a substance that can normally exist independenty
Moles=mass/molar mass of water. the molar mass of water is found to be 18g which is calculated adding the molar mass of hydrogen plus that of oxygen that is(2x 16)+(1 x2)=18g/mol
convert Kg to grams that is 1.8kg x 1000=1800g
moles is therefore 1800g /18g/mol=100 mol
The Equation is CaH2(s)+2H2O(l)-->Ca(OH)2(aq)+2H2(g)
so,
moles of H2 generated = PV / RT
R = 62.363 L Torr K−1 mol−1
number of moles = 814 * 53.5 / 62.363 * 293
= 2.38 moles
looking at the equation these came from 2.38 /2 moles of CaH2 or 1.19 moles
Molar mass of CaH2 is 42.0943 g/mol
so mass of CaH2 = 1.19 X 42.1 = 50.01g
