A0.4243-g sample of caco 3 is dissolved in 12 m hcl and the resulting solution is diluted to 250.0 ml
in a volumetric flask. how many moles of caco 3 are used (formula mass = 1 00.1 )?

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