# Chemistry

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1. How many moles of Al(CN)3 are in 199 g of the compound?

2. 96.0 mol of P4O10 contains how many moles of P?

3. If 4.71 moles of C5H12 reacts with excess O2, how many moles of CO2 will be produced in the following combustion reaction? C5H12+8O2 -> 6H20+5CO2

4. How many grams of O2(g) are needed to completely burn 51.0 g of C3H8(g)?
C3H8+5O2 -> 3CO2+4H2O

5. How many grams of sodium iodide, NaI, must be used to produce 69.9 g of iodine, I2? 2NaI+Cl2 -> I2+2NaCl

6. What is the average atomic mass of titanium on that planet?
Isotope: 46Ti
Abudance: 70.900%
Mass(amu): 45.95263
Isotope: 48Ti
Abudance: 10.000%
Mass(amu): 47.94795
Isotope: 50Ti
Abundance: 19.100%
Mass(amu): 49.94479

• Chemistry - ,

You would do well to restrict posts in the future to one problem per post.

1. How many moles of Al(CN)3 are in 199 g of the compound?

mol = g/molar mass

2. 96.0 mol of P4O10 contains how many moles of P?

mol = g/molar mass

3. If 4.71 moles of C5H12 reacts with excess O2, how many moles of CO2 will be produced in the following combustion reaction? C5H12+8O2 -> 6H20+5CO2

Here is a worked example. Just follow the steps.
" target="_blank">http://www.jiskha.com/science/chemistry/stoichiometry.html

4. How many grams of O2(g) are needed to completely burn 51.0 g of C3H8(g)?
C3H8+5O2 -> 3CO2+4H2O
See problem 3.

5. How many grams of sodium iodide, NaI, must be used to produce 69.9 g of iodine, I2? 2NaI+Cl2 -> I2+2NaCl

See problem 3.

6. What is the average atomic mass of titanium on that planet?
Isotope: 46Ti
Abudance: 70.900%
Mass(amu): 45.95263
Isotope: 48Ti
Abudance: 10.000%
Mass(amu): 47.94795
Isotope: 50Ti
Abundance: 19.100%
Mass(amu): 49.94479

Take the three isotopes.
(abundance x amu) + (abundance x amu) + (abundance x amu) = average. The average is what you calculate.

• Chemistry - ,

On the last problem (#6) abundance goes in as a fraction.