How many atoms are in 0.500 g of Magnesium Chloride?

3.16 × 10²¹ atoms MgCl₂

General Formulas and Concepts:

Explanation:

Step 1: Define

0.500 g MgCl₂ (Magnesium Chloride)

Step 2: Define conversion

Molar Mass of Mg - 24.31 g/mol

Molar Mass of Cl - 35.45 g/mol

Molar Mass of MgCl₂ - 24.31 + 2(35.45) = 95.21 g/mol

Avagadro's Number: atoms

Step 3: Dimensional Analysis

= 3.16248 × 10²¹ atoms MgCl₂

Step 4: Check

We are given 3 sig figs. Follow sig fig rules.

3.16248 × 10²¹ atoms MgCl₂ ≈ 3.16 × 10²¹ atoms MgCl₂

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e

b.

the accuracy of the data.