What mass of calcium carbide is needed to produce 0.5 mol of ethyne by reaction with water (Ca = 40, C = 12)?
Correct answer C. 32 g
Explanation
CaC₂ + 2H₂O → Ca(OH)₂ + C₂H₂, a 1:1 ratio. Molar mass of CaC₂ is 64 g mol⁻¹, so 0.5 mol requires 32 g.
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