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1.2 g of mg is burnt in a closed vessel which contains 0.5 g of o2. millimeters of 0.5 m h2so4 required to dissolve the residue in the vessel is?

Prerna Ranasingh , 8 Years ago
Grade 12th pass
anser 2 Answers
suvra bhattacharjee
The equation is as follows:
2Mg + O2  ------>  2MgO
(s)      (g)                (s)
Therefore 2 moles of Mg require 1 mole of O2 to produce 2 moles of MgO.
Calculate actual moles.
moles= mass/ molar mass
Mg=    1/24  = 0.041667
O2=   0.56/32 = 0.0175
MgO=
Mole ratio of Mg: O2   = 2:1
find mass of Mg that reacts:
that means 2 mole of Mg reacts with 1 moles of O2
If 1 = 2 
Then 0.0175 = 0.0175 x 2
                     =0.035 moles of magnesium
mass of magnesium that reacts:
mass= moles x molar mass
        = 24 x 0.035
         
              0.84 g
That means that of the 1 gram of magnesium that reacts only 0.84 grams is used
Therefore magnesium is in excess and by 0.16
 
Last Activity: 7 Years ago
Sheeba Roohi
Eq. Of Mg = 1.2÷12=0.1
Eq. Of O² = 0.5÷8 = 0.0625
Therefore Eq. Of MgO = 0.0625
Eq. Of mg left = 0.1-0.0625=0.0375
Eq. Of H²SO⁴=0.0375+0.0625
=0.1
Vol. of H²SO⁴ = 0.1÷0.25×2=0.2L =200mL
Last Activity: 7 Years ago
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