Calculating the Mass of Zinc Atoms: A Step-by-Step Guide
Introduction and Importance of Molar Mass and Avogadro's Number
Understanding the concepts of molar mass and Avogadro's number is essential in chemistry, particularly when dealing with atomic-level calculations. This guide will walk you through the steps to calculate the mass of 3.75 x 10^21 atoms of zinc. Before we dive in, it's crucial to grasp the significance of these concepts.
Understanding Molar Mass and Avogadro's Number
Molar mass is the mass of one mole of a substance, expressed in grams per mole (g/mol). On the other hand, Avogadro's number (also known as Avogadro's constant) is the number of atoms, molecules, or formula units in one mole of a substance, which is approximately 6.022 x 10^23.
Step-by-Step Calculation: Mass of Zinc Atoms
Let's begin with the given data:
About 3.75 x 10^21 atoms of zinc. Molar mass of zinc (Zn) 65.38 g/mol. Determine the number of moles of zinc: Number of moles (n) Number of atoms / Avogadro's number n (3.75 x 10^21 atoms) / (6.022 x 10^23 atoms/mol) 6.22 x 10^-3 moles Calculate the mass of zinc: Mass (m) Number of moles (n) x Molar mass (M) m (6.22 x 10^-3 moles) x (65.38 g/mol) 0.407 gTherefore, the mass of 3.75 x 10^21 atoms of zinc is approximately 0.407 grams.
The Role of Unit Cancellation in Chemistry Problems
This method of working through chemical problems is often called unit cancellation, unit factor, or dimensional analysis. It involves using conversion factors to convert units from one form to another. Let's see how this works with the example given:
3.75 x 10^21 atoms Zn x (1 mol / 6.022 x 10^23 atoms) x (65.38 g / 1 mol) 0.407 g
Conclusion and Practical Application
Understanding how to convert between atomic quantities and grams using molar mass and Avogadro's number is a fundamental skill in chemistry. Practicing these calculations will help you tackle more complex problems and ensure accuracy in your work.
Related Keywords: molar mass, Avogadro's number, atomic mass