Question

activity: solutions
a. for each of the following mixtures, identify the solute and the solvent.

1. 10 g of sugar dissolved in 200 ml of tea
2. 30 ml of oxygen mixed with 70 ml of nitrogen (air)
3. brass, an alloy made of 30% zinc and 70% copper
4. 50 ml of ethanol mixed with 25 ml of water
5. 12 g of iodine crystals placed in 100 ml of ethanol
6. soda water made by dissolving carbon dioxide under pressure in water
7. bronze, an alloy made of 10% tin and 90% copper
8. hydrogen gas dissolved in palladium metal
9. 25 g of sodium hydroxide pellets dissolved in 75 ml of water
10. perfume (a solution of fragrant oils in alcohol)

Explanation:

Step1: Recall solute - solvent concept

The solute is the substance that is dissolved, and the solvent is the substance in which the solute is dissolved.

Step2: Analyze each mixture

For sugar - tea mixture, sugar is dissolved in tea. For oxygen - nitrogen, oxygen is the minor component dissolved in nitrogen. In alloys, the minor component is the solute and the major one is the solvent. In ethanol - water, ethanol is in larger volume so it is considered the solute here. For iodine - ethanol, iodine is dissolved in ethanol. In soda - water, carbon dioxide is dissolved in water. In bronze, tin is the solute in copper. For hydrogen - palladium, hydrogen is dissolved in palladium. For sodium hydroxide - water, sodium hydroxide is dissolved in water. In perfume, fragrant oils are dissolved in alcohol.

Answer:

1. Solute: Sugar; Solvent: Tea
2. Solute: Oxygen; Solvent: Nitrogen
3. Solute: Zinc; Solvent: Copper
4. Solute: Ethanol; Solvent: Water
5. Solute: Iodine; Solvent: Ethanol
6. Solute: Carbon dioxide; Solvent: Water
7. Solute: Tin; Solvent: Copper
8. Solute: Hydrogen gas; Solvent: Palladium metal
9. Solute: Sodium hydroxide; Solvent: Water
10. Solute: Fragrant oils; Solvent: Alcohol