How many mL does 1.5 teaspoons make?

1. Convert 1 teaspoon to mL: 1 \text{ teaspoon} = 4.92892 \text{ mL}
2. Multiply the volume in teaspoons by the mL conversion factor: 1.5 \text{ tsp} \times 4.92892 \text{ mL/tsp} = 7.39338 \text{ mL}

Answer: 7.39338 \text{ mL}