Need help with chemistry (1 Viewer)

[lazyandcool]

1) if one mole of calcium reacts how many moles of hydrogen will be formed?
2)Calculate the volume of the hydrogen formed at 25 degrees and 100k pA if 4.5g of calcium reacts with excess acid(1 mole of gas at 25 degrees and 100k Pa=24.79L)

 

[hscishard]

1) if one mole of calcium reacts how many moles of hydrogen will be formed?
2)Calculate the volume of the hydrogen formed at 25 degrees and 100k pA if 4.5g of calcium reacts with excess acid(1 mole of gas at 25 degrees and 100k Pa=24.79L)

1) doesn't make sense.

 

[random-1005]

1) if one mole of calcium reacts how many moles of hydrogen will be formed?
2)Calculate the volume of the hydrogen formed at 25 degrees and 100k pA if 4.5g of calcium reacts with excess acid(1 mole of gas at 25 degrees and 100k Pa=24.79L)

you need to know the acid, never the less i will assume it is sulphuric ( if it is hydrochloric it is just a matter of changing the eqn, you will get slightly harder mole ratios, but no big deal.

Ca + H2SO4 --> CaSO4 + H2 ( balanced reaction equation)


mass Ca= 4.5g
molar mass Ca (from periodic table/ data sheet) = 40g/mol

Molar mass = mass of one mole ( M= m/n)
n= m/M= 4.5/40= 0.11moles

from reaction eqn, ratio of moles of Ca reacted to H2 produced is 1/1 ( the coeffiecents of the substances)

therefore 0.11 moles H2 is produced.

Volume H2= 0.11 x 24.79 = 2.7L

if it has HCL, ( which i suspect it is from part a of the question) the only difference will the eqn

in that case Ca +2HCL --> CaCl2 +H2 ( huh, interesting, that wouldnt change the answer either)