2. What is a mole? A mole is a number. It is 6.022 x 10 23 This number is also called Avogadro’s number. How many atoms in 1 mole of copper atoms? 6.022 x 10 23 atoms How many molecules in 1 mole of water molecules? 6.022 x 10 23 molecules How many atoms in 1 mole of water molecules? 6.022 x 10 23 x 3 =

3. What is molar mass? The mass of one mole is called the molar mass. It is the same as the atomic mass, but measured in grams. What is the mass of 1 mole of copper atoms? 63.5 g. What is the mass of 1 copper atom ? 63.5 amus

4. SubstanceFormulaHow many molecules in 1 mole? How many atoms in 1 mole? How many grams in 1 mole? CopperCu6.022 x 10 23 molecules 6.022 x 10 23 atoms 63.5 g Atomic nitrogen Nitrogen gas Water Calcium Hydrogen atom Hydrogen gas

5. Practice problems How many moles is 1.50 x 10 23 molecules of NH 3 ?

6. How many atoms are in 1.75 moles of CHCl 2 ?

7. How many moles of magnesium is 1.25 x 10 23 atoms?

8. How many grams are in 5.66 moles of CaCO 3 ?

9. The mole-volume relationship Avogadro’s hypothesis (1811) states that equal volumes of gases at the same temperature and pressure contain equal numbers of particles.

10. STP Standard temperature and pressure (STP) means a temperature of 0 0 C and a pressure of 1 atmosphere (or 760 mm Hg or 101.3 kPa). At STP I mole of gas, or 6.022 x 10 23 particles, occupy 22.4 L. This is called the molar volume of the gas.

11. What is the volume of 3.70 moles of N 2 at STP?

12. What is the volume of 3.20 x 10 -3 moles of CO 2

13. How many moles of gas in 67.2 L of SO 2 at STP

14. How many moles of gas in 0.880 L of He at STP?

15. How many moles of gas in 1.00 x 10 3 L of C 2 H 6