When iron reacts with oxygen in the air , it forms iron (iii) oxide or rust .

how many grams of iron (iii) oxide would be formed if 2 moles of iron completely react with oxygen gas ?

a. 319.2 g

b. 159.6 g

c. 71.8 g

d. 143.6 g

B. 159.6 g

Explanation:

balanced reaction:

∴ moles taht react of Fe = 2 mol

∴ mm Fe = 55.845 g/mol

⇒ g Fe2O3 = ?

∴ moles Fe2O3 = ( 2 mol Fe )×( 2 mol Fe2O3/ 4 mol Fe ) = mol Fe2O3

∴ mm Fe2O3 = 159.6882 g/mol

⇒ g Fe2O3 = ( 1 mol Fe2O3 )×( 159.6882 g/mol) = 159.6882 g

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

um i think it might be a car?