Help me please someone

Question

Consider a 2.87 g sample of C4H10C4H10. How many molecules are in this sample? Report your answer with 3 significant figures and in scientific notation. Use * for the multiplication symbol.

Answer 1

Janet,

First, convert your mass in grams to moles by using the molar mass, then convert the moles to molecules, using Avogadro's number.

The molar mass of C₄H₁₀ is 58.122 g/mol

Avogadro's number = 6.022 * 10²³ molecules/mol

To convert from mass to moles, divide by the molar mass:

2.87 g * 1 mol/58.122 g = 0.0494 moles

To convert from moles to molecules, multiply by Avogadro's number:

0.0494 moles * 6.022*10²³ molecules/mol = 2.97 * 10²² molecules