Chapter 3, Problem 3.6P

(a)

Interpretation Introduction

Interpretation:

The correct number of significant figures for the molecular mass of ${\text{BaCl}}_{\text{2}}$ has to be found.

Concept introduction:

Significant figures: The digits having a meaning in a given number are called as significant figures.

Significant figures – calculation rules

• Significant figure is a non-zero number (4443.2 has five significant figures)
• Zeros placement in between non-zero number are significant figures (40005 has five significant figures).
• Zeros before the non-zero number are not significant number (0.00040005 has five significant figures).
• Zeros after the non-zero number are significant in case of that number contains decimal point (4.5000 has five significant figures).
• Zeros after the non-zero number may or may not be a significant figure in case of that number does not have a decimal point (500 may have 1, 2 or 3 significant figures).  In this cases use scientific notation to avoid ambiguity.

(b)

Interpretation Introduction

Interpretation:

The correct number of significant figures for the molecular mass of ${\text{C}}_{\text{31}}{\text{H}}_{\text{32}}{\text{O}}_{\text{8}}{\text{N}}_{\text{2}}$ has to be found.

Concept Introduction:

Refer part (a).