Pure substances and mixtures Original Scenario-Based Download PDF

Questions

1. 1.

   During an expedition to an uncharted crystal cavern, an astro-chemist collects four mysterious samples labeled with distinct physical and chemical observations: Sample X melts sharply at 115 °C and cannot be separated into simpler substances by any physical or chemical method; Sample Y boils at a constant 78 °C and decomposes into two new gaseous substances when exposed to an electric arc; Sample Z consists of two visibly distinct crystalline layers that can be mechanically separated; and Sample W is a completely transparent liquid that leaves a white crystalline crust behind after gentle heating. Based on fundamental chemical principles of matter, which conclusion correctly classifies these specimens?

   • A) Samples X and Y are pure substances, whereas Samples Z and W are mixtures.
   • B) Samples X and W are pure substances, whereas Samples Y and Z are mixtures.
   • C) Only Sample X is a pure substance, while Samples Y, Z, and W are all mixtures.
   • D) Samples Y and Z are compounds, whereas Samples X and W are homogeneous solutions.