Combined Gas Law Practice: A closed gas system initially has a volume and temperature of 1190mL and 334K with the pressure unknown. If the same closed system has values of 768 torrs, 2.3 L, and 394K, what was the initial pressure in the atm?

1. 1 mole of anything contains 6.022x10^23 pieces  

d  

2. a  

3. c, number  

5. 1.24x10^24atoms / 6.022x10^23atoms/mole = 2moles h2 atoms  

6. fe2br3 mass = 2moles x mass fe + 3 moles x mass br  

molar mass = grams / number of moles = g/mole  

to find moles = g / molar mass  

to find mass = g = molar mass / moles

the answers would be

the first one and the second one