Question

A block of ice with a molar mass of 20 mg contains 2.5 mole particles.

A) How many particles are in the block?
A) 3.01 × 10^23 particles
B) 5.02 × 10^23 particles
C) 1.51 × 10^23 particles
D) 4.81 × 10^23 particles

Answer 1

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.