The table describes how some substances were formed.
| Substance | Description |
|---|---|
| $P$ | Formed by boiling pure water |
| $Q$ | Formed by combining three hydrogen atoms to every nitrogen atom |
| $R$ | Formed by adding 5 g of sugar to 1 L of water |
| $S$ | Formed by compressing carbon under high pressure |
Based on the given descriptions, which substance is most likely a mixture?
P
Q
R
S
Answer (1)
Substance P involves a phase change of a single substance.
Substance Q describes the formation of a chemical compound.
Substance R involves dissolving sugar in water, creating a mixture.
Substance S involves changing the form of a single substance.
Therefore, the substance most likely a mixture is R .
Explanation
Understanding the Problem We need to determine which of the given substances (P, Q, R, or S) is most likely a mixture based on their descriptions. A mixture is formed by combining two or more different substances without a chemical reaction.
Analyzing Substance P Substance P is formed by boiling pure water. Boiling is a phase change (liquid to gas), but it's still the same substance (water). So, P is not a mixture.
Analyzing Substance Q Substance Q is formed by combining three hydrogen atoms to every nitrogen atom. This describes the formation of ammonia ( N H 3 ), which is a chemical compound, not a mixture.
Analyzing Substance R Substance R is formed by adding 5 g of sugar to 1 L of water. Sugar dissolving in water creates a mixture because the sugar and water retain their individual properties and are not chemically bonded.
Analyzing Substance S Substance S is formed by compressing carbon under high pressure. This changes the form of carbon (e.g., graphite to diamond), but it's still pure carbon. So, S is not a mixture.
Conclusion Based on the analysis, substance R (sugar dissolved in water) is the most likely mixture.
Examples
Mixtures are common in everyday life. For example, when you make a cup of coffee, you're creating a mixture of coffee grounds and water. Similarly, the air we breathe is a mixture of nitrogen, oxygen, and other gases. Understanding mixtures is crucial in fields like chemistry, cooking, and environmental science, where separating and analyzing different substances is essential.
