Question

Is iced water a pure substance? Why?

Short answer

Explain your reasoning. Answer: No, iced water is not a pure substance. Although both ice and liquid water consist of H2O molecules, the presence of two different physical states (solid and liquid) in iced water demonstrates that it is not a homogenous mixture. A pure substance must have a homogenous composition, which iced water does not have.

Step-by-step solution

Understand the concept of a pure substance

A pure substance is a material that has a homogenous composition, with no discernible separately identifiable parts. It can be an element or a compound made of unique types of atoms bonded together. In other words, a pure substance has the same composition throughout and cannot be separated into different components by simple physical methods.

Analyze the composition of iced water

Iced water can be considered as a mixture of two components: ice and liquid water. Ice is the solid-state version of water, whereas liquid water is the liquid-state version. Both are formed from water molecules, that consist of two hydrogen atoms and one oxygen atom (H\(_2\)O).

Compare the composition of iced water to the definition of a pure substance

Since iced water consists of ice and liquid water, two different states of the same compound, one can argue that it's not a homogenous combination. Though both ice and water consist of H\(_2\)O molecules, the presence of two states indicates that the iced water is not a pure substance based on the definition provided earlier. It is instead a mixture of two forms of the same substance.

Conclusion

Iced water is not considered a pure substance because it contains both ice (solid-state water) and liquid water, making it a mixture of two physical states of the same compound. A pure substance must have a homogenous composition, which iced water does not have due to the presence of both solid and liquid forms of water.