Let's analyze each substance based on its description to determine which one is most likely a mixture.
1. Substance P: Formed by boiling pure water
- Boiling pure water will result in steam, which is still composed of pure water (H₂O) molecules. This means Substance P is a pure substance because it consists of only one type of molecule.
2. Substance Q: Formed by combining three hydrogen atoms to every nitrogen atom
- This description matches the chemical compound ammonia (NH₃), which is formed by chemically bonding three hydrogen atoms to one nitrogen atom. This combination results in a distinct compound with specific properties, making Substance Q a chemical compound and not a mixture.
3. Substance R: Formed by adding 5 g of sugar to 1 L of water
- Adding sugar to water creates a solution where the sugar (solute) dissolves in the water (solvent). This results in a homogeneous mixture because the sugar molecules are dispersed within the water but not chemically bonded to the water molecules. Substance R is a mixture.
4. Substance S: Formed by compressing carbon under high pressure
- Compressing carbon under high pressure can result in the formation of either diamond or graphite. Both diamond and graphite are crystalline forms of pure carbon and are considered pure substances since they consist only of carbon atoms.
Considering the above analysis, we can conclude that:
- Substance P is a pure substance (steam).
- Substance Q is a chemical compound (ammonia).
- Substance R is a mixture (sugar solution).
- Substance S is a pure substance (diamond or graphite).
Therefore, the substance that is most likely a mixture is:
R
