If 1.25 L of acetylene at 0.750 atm can be made from 5.00 g of limestone

If 1.25 L of acetylene at 0.750 atm can be made from 5.00 g of limestone

 

 

Calcium carbide, CaC2, is made by heating lime, CaO, with carbon. The lime is made by heating limestone, CaCO3. Acetylene, C2H2, can be made from the calcium carbide by reacting it with water:

CaC2(s) + 2H2O(l) → Ca(OH)2(aq) + C2H2(g)

 

If 1.25 L of acetylene at 0.750 atm can be made from 5.00 g of limestone, what is the temperature of the gas?

 

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CaCO3(s) → CaO(s) + CO2(g)

CaO(s) + 3C(s) → CaC2(s) + CO(g)

CaC2(s) + 2H2O(l) → Ca(OH)2(aq) + C2H2(g)

 

CaCO3 (몰질량 100.09 g/mol) 5.00 g의 몰수를 구하면,

5.00 g / (100.09 g/mol) = 0.0500 mol CaCO3

 

CaCO3 : CaO : CaC2 : C2H2 = 1 : 1 : 1 : 1 반응 비이므로,

0.0500 mol CaCO3가 반응하면, 0.0500 mol C2H2가 생성됩니다.

 

PV = nRT

T = PV / nR

= [(0.750)(1.25)] / [(0.0500)(0.0821)]

= 228.38 K = –44.77℃