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Calcium hydride and water?
Hydrogen gas can be produced from the reaction of calcium hydride and water.
CaH2(s) + 2H2O(l) --> 2H2(g) + Ca(OH)2(aq)
How many grams of calcium hydride are needed to produce 1.5 L of hydrogen gas, collected over water at 26 C and 760 torr total pressure.
How do I do this? Help! Thanks in advance.
2 Answers
- 1 decade agoFavorite Answer
2H2
pv = nrt
n = pv / rt
n = (101.325kpa)(1.5L) / (8.314472)(299k)
n = 0.0611367 mols
CaH2
n = (0.0611367mols)(.5)
= 0.030568351
n = m / M
m = nM
= (0.030568351mols)(42.01g/mol)
= 1.286927577 g
= 1.29 grams
Source(s): I think it's right. - geek.....Lv 71 decade ago
step 1: convert C to K, torr to atm
step 2: look up value for 26 C vapor pressure and substract difference from torr
step 3: use ideal gas law and solve for n
step 4: mol CaH2 to mol H2, mol to g H2
good luck.
