Final answer:
To find the number of particles in a block of ice containing 2.5 moles, you multiply 2.5 by Avogadro's number (6.022 × 10²³ particles/mole) to get 1.51 × 10²³ particles.
Step-by-step explanation:
The question is asking us to calculate the number of particles in a block of ice containing 2.5 moles. We know that one mole of a substance consists of Avogadro's number of particles, which is 6.022 × 10²³ particles. Therefore, to find the number of particles in 2.5 moles, we multiply 2.5 by Avogadro's number.
Calculation: 2.5 moles × 6.022 × 10²³ particles/mole = 1.5055 × 10²´ particles
In scientific notation, rounded to 3 significant figures, this is 1.51 × 10²³ particles, which corresponds to answer C.