Tin occurs naturally in the form of the cassiterite mineral SnO2. Calculate the mass fraction of metal in this compound. Find the mass of cassiterite required to obtain 250 kg of tin.
Given: SnO2, m (Sn) = 250 kg. Find: ω (Sn) – ?, m (SnO2) -?
1. Calculate the mass fraction of tin in the SnO2 mineral.
Mr (SnO2) = Ar (Sn) + 2 • Ar (O) = 119 + 2 • 16 = 151
ω (Sn) = (Ar (Sn) / Mr (SnO2)) • 100% = (119: 151) • 100% = 78.81%
2. Calculate the mass of cassiterite:
m (SnO2) = (m (Sn): ω (Sn)) • 100% = (250 kg: 78.81%) • 100% = 317 kg.
Answer: ω (Sn) = 78.8%, m (SnO2) = 317 kg.
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