Name:_______________________________
Date:_________________
Per:____
WS 9.5: Stoich & Present Composition
Fe +
CuCl2 →
FeCl2 +
Cu
1. How many atoms of Fe would it take to generate 65g of copper?
𝑔 𝐶𝑢
)(
1
(
𝑚𝑜𝑙 𝐶𝑢
)(
𝑔 𝐶𝑢
𝑚𝑜𝑙 𝐹𝑒
)(
𝑚𝑜𝑙 𝐶𝑢
𝑎𝑡𝑜𝑚𝑠 𝑜𝑓 𝐹𝑒
)
𝑚𝑜𝑙 𝐹𝑒
2. How many grams of Fe would be reacted to produce 65g copper?
(
𝑔 𝐶𝑢
)(
1
)(
KClO3 →
)(
KCl +
)
O2
3. How many liters of oxygen will be produced from 57 grams of potassium chlorate?
𝑔 𝐾𝐶𝑙𝑂3
)(
1
(
𝑚𝑜𝑙 𝐾𝐶𝑙𝑂3
)(
𝑔 𝐾𝐶𝑙𝑂3
𝑚𝑜𝑙 𝑂2
)(
𝑚𝑜𝑙 𝐾𝐶𝑙𝑂3
𝐿 𝑂2
)
𝑚𝑜𝑙 𝑂2
4. How many atoms of oxygen would 57g of KCLO3 would make ?
𝑔 𝐾𝐶𝑙𝑂3
(
1
)(
)(
HCl →
Mg +
)(
)
H2 + MgCl2
5. How many liters of hydrogen will be produced from reacting 12.04x1024 molecules of HCl?
(
𝑀𝑜𝑙𝑖𝑐 𝐻𝐶𝑙
1
)(
𝑚𝑜𝑙 𝐻𝐶𝑙
)(
𝑀𝑜𝑙𝑖𝑐 𝐻𝐶𝑙
𝑚𝑜𝑙 𝐻2
)(
𝑚𝑜𝑙 𝐻𝐶𝑙
𝐿𝐻2
)
𝑚𝑜𝑙 𝐻2
6. How many grams of Hydrogen would 12.04x1024 molecules of HCl make?
(
𝑀𝑜𝑙𝑖𝑐 𝐻𝐶𝑙
1
)(
)(
)(
)
C5H10 +
O2 →
CO2 +
H2 O
7. How many grams of H20 will be generated from 140 grams of pentene?
(
𝑔 𝐶𝑢
)(
1
𝑚𝑜𝑙 𝐶𝑢
)(
𝑔 𝐶𝑢
𝑚𝑜𝑙 𝐹𝑒
)(
𝑚𝑜𝑙 𝐶𝑢
𝑎𝑡𝑜𝑚𝑠 𝑜𝑓 𝐹𝑒
)
𝑚𝑜𝑙 𝐹𝑒
8. 140g of pentene combusting would make how many L of water vaper?
𝑔 𝐶𝑢
)(
1
(
)(
CO2 →
)(
C +
)
O2
9. If 44.8 L of O2 are produced from the decomposition of carbon dioxide, how many liters of carbon
dioxide decomposed?
(
𝑔 𝐶𝑢
)(
1
𝑚𝑜𝑙 𝐶𝑢
)(
𝑔 𝐶𝑢
𝑚𝑜𝑙 𝐹𝑒
)(
𝑚𝑜𝑙 𝐶𝑢
𝑎𝑡𝑜𝑚𝑠 𝑜𝑓 𝐹𝑒
)
𝑚𝑜𝑙 𝐹𝑒
10. If 44.8 L of O2 are produced from the decomposition of carbon dioxide, how many liters of carbon
dioxide decomposed?
(
𝑔 𝐶𝑢
)(
1
)(
)(
)
11. A 3.6 sample is found to contain only carbon and iron. Given that the sample contains 1.68 g of iron,
calculate the percentage composition of the compound.
12. Find the percentage composition of a compound that contains 4.8 g of hydrogen, 19.4 g of carbon, , and
25.8 g of sulfur in a 50.0 g sample of the compound.
13. A sample of an unknown compound with a mass of 16.5g has the following composition: 86.2%
nitrogen and the rest 13.8% chlorine. When this compound is decomposed into its elements, what mass
of each element would be recovered?