A student is given four solid samples labeled W, X, Y, and Z. All have a metallic luster. She is told that the solids could be gold, lead sulfide, mica (which is quartz, or SiO2), and iodine. The results of her investigations are: W is a good electrical conductor; X, Y, and Z are poor electrical conductors. When the solids are hit with a hammer, W flattens out, X shatters into many pieces, Y is smashed into a powder, and Z is not affected. When the solids are heated with a Bunsen burner, Y melts with some sublimation, but X, W, and Z do not melt. In treatment with 6 M HNO3, X dissolves; there is no effect on W, Y, or Z. On the basis of these test results, identify the solids.

Question

Jeffrey Reese

Chemistry

14 September, 00:03

A student is given four solid samples labeled W, X, Y, and Z. All have a metallic luster. She is told that the solids could be gold, lead sulfide, mica (which is quartz, or SiO2), and iodine. The results of her investigations are: W is a good electrical conductor; X, Y, and Z are poor electrical conductors. When the solids are hit with a hammer, W flattens out, X shatters into many pieces, Y is smashed into a powder, and Z is not affected. When the solids are heated with a Bunsen burner, Y melts with some sublimation, but X, W, and Z do not melt. In treatment with 6 M HNO3, X dissolves; there is no effect on W, Y, or Z. On the basis of these test results, identify the solids.

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Maeve · Answer 1

W is Gold because it is a good conductor of electricity, it is also malleable hence its flattened out.

X is lead sulfide since it dissolved in HNO₃ with the production nitric oxide gas

3 PbS + 8 HNO₃ → 3 PbSO₄ + 8 NO + 4 H₂O

Y is Iodine, Iodine like some solids undergoes sublimation (change of state from solid directly to gas)

Z is mica