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

1. To find the number of moles of Al(CN)3 in 199 g of the compound, you need to use the formula:

Number of moles = Mass of compound / Molar mass of compound

The molar mass of Al(CN)3 can be calculated by adding up the atomic masses of each element in the compound.

Atomic mass of Al = 26.98 g/mol
Atomic mass of C = 12.01 g/mol
Atomic mass of N = 14.01 g/mol

To calculate the molar mass of Al(CN)3:
Molar mass of Al(CN)3 = (26.98 g/mol) + 3*(12.01 g/mol) + 3*(14.01 g/mol)

Now you can plug in the values to find the number of moles:
Number of moles = 199 g / Molar mass of Al(CN)3

2. To find the number of moles of P in 96.0 mol of P4O10, you need to use the formula:

Number of moles = Number of moles of compound * (Number of moles of P / Number of moles of compound)

In P4O10, there are 4 moles of P for every 1 mole of P4O10. So you can set up the equation:

Number of moles of P = 96.0 mol * (4 mol P / 1 mol P4O10)

3. To find the number of moles of CO2 produced in the combustion reaction, you need to use the balanced equation and the stoichiometry.

From the balanced equation:
1 mole of C5H12 reacts to produce 5 moles of CO2

So, for 4.71 moles of C5H12:
Number of moles of CO2 = 4.71 mol C5H12 * (5 mol CO2 / 1 mol C5H12)

4. To find the grams of O2 needed to burn 51.0 g of C3H8, you need to use the balanced equation and the stoichiometry.

From the balanced equation:
1 mole of C3H8 reacts with 5 moles of O2

First, find the number of moles of C3H8:
Number of moles of C3H8 = Mass of C3H8 / Molar mass of C3H8

Then, use the stoichiometry to find the number of moles of O2:
Number of moles of O2 = Number of moles of C3H8 * (5 mol O2 / 1 mol C3H8)

Finally, calculate the mass of O2 in grams:
Mass of O2 = Number of moles of O2 * Molar mass of O2

5. To find the grams of sodium iodide (NaI) needed to produce 69.9 g of iodine (I2), you need to use the balanced equation and the stoichiometry.

From the balanced equation:
2 moles of NaI react to produce 1 mole of I2

First, find the number of moles of I2:
Number of moles of I2 = Mass of I2 / Molar mass of I2

Then, use the stoichiometry to find the number of moles of NaI:
Number of moles of NaI = Number of moles of I2 * (2 mol NaI / 1 mol I2)

Finally, calculate the mass of NaI in grams:
Mass of NaI = Number of moles of NaI * Molar mass of NaI

6. To find the average atomic mass of titanium, you need to calculate the weighted average of the atomic masses of its isotopes using their respective abundances.

Multiply the mass of each isotope by its abundance and then sum the products.

Average atomic mass of titanium = (Abundance1 * Mass1) + (Abundance2 * Mass2) + (Abundance3 * Mass3)

For 46Ti:
(70.9% * 45.95263 amu) +

For 48Ti:
(10.0% * 47.94795 amu) +

For 50Ti:
(19.1% * 49.94479 amu)

Add up the three terms to find the average atomic mass of titanium.

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

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.