Part 1 :

a.) How many grams of Hydrogen will be contained in a 100.000 g sample of magnesium hydroxide.?

c.) How many grams of nitrogen will be contained in a 120.0 g sample of calcium cyanide?
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Part 3:

d.) How many grams of nickel will be contained in a 400. g sample of nickel (ii) iodide?

f) How many grams of copper will be contained in a 165.0 g sample of copper (i) Sulfide?

g.) How many grams of sulfur will be contained in a 125.5 g sample of hexaphosphorus pentasulfide?

a.) How many grams of Hydrogen will be contained in a 100.000 g sample of magnesium hydroxide.?

mols MgIOH)2 = grams/molar mass = ?
Then mols H ATOMS (not molecules) will be twice that since there are two H atoms per mol Mg(OH)2.
Then grams H ATOMS will be g = mols x atomic mass. I assume you want g H atoms and not g H molecules (i.e., H2).


c.) How many grams of nitrogen will be contained in a 120.0 g sample of calcium cyanide?
See the previous problem. ______________
Part 3:

d.) How many grams of nickel will be contained in a 400. g sample of nickel (ii) iodide?
See previous problems

f) How many grams of copper will be contained in a 165.0 g sample of copper (i) Sulfide?

See previous problems.

g.) How many grams of sulfur will be contained in a 125.5 g sample of hexaphosphorus pentasulfide?
See previous problems
Someone will be glad to check your answers if you post your work (not just the answers)

To calculate the number of grams of a specific element in a compound, you need to know the molar mass of the compound and the molar mass of the element. The molar mass is the mass of one mole of a substance and is usually expressed in grams per mole (g/mol). Here's how you can solve each question:

Part 1:

a) Magnesium hydroxide has the chemical formula Mg(OH)2. To find the molar mass of magnesium hydroxide, you need to add up the atomic masses of each element in the compound.

Molar mass of Mg(OH)2 = (atomic mass of Mg) + 2 * (atomic mass of O) + 2 * (atomic mass of H)

You can find the atomic masses from the periodic table. The atomic mass of Mg is 24.31 g/mol, O is 16.00 g/mol, and H is 1.01 g/mol.

Molar mass of Mg(OH)2 = 24.31 + 2 * 16.00 + 2 * 1.01 g/mol
Molar mass of Mg(OH)2 = 58.33 g/mol

Now, using the molar mass of Mg(OH)2, you can calculate the number of moles of magnesium hydroxide in the 100.000 g sample. To do this, divide the mass of the sample by the molar mass.

Number of moles = mass / molar mass
Number of moles = 100.000 g / 58.33 g/mol

Finally, to find the number of grams of hydrogen in the sample, you need to consider the ratio of moles between hydrogen and magnesium hydroxide. The compound has a 1:2 ratio of hydrogen to magnesium hydroxide.

Number of grams of hydrogen = number of moles of Mg(OH)2 * (2 moles of H / 1 mole of Mg(OH)2) * (molar mass of H)

Substitute the number of moles calculated earlier and the molar mass of hydrogen (1.01 g/mol) into the formula above to get the answer.

c) Calcium cyanide has the chemical formula Ca(CN)2. Follow the same steps as above to calculate the grams of nitrogen in the 120.0 g sample of calcium cyanide. The atomic masses you'll need are: Ca (40.08 g/mol), C (12.01 g/mol), and N (14.01 g/mol).

Part 3:

d) Nickel (II) iodide has the chemical formula NiI2. Calculate the molar mass of NiI2 using the atomic masses of Ni (58.69 g/mol) and I (126.90 g/mol). Then use the same procedure as in Part 1 to calculate the grams of nickel in the 400.0 g sample.

f) Copper (I) sulfide has the chemical formula Cu2S. Calculate the molar mass of Cu2S using the atomic masses of Cu (63.55 g/mol) and S (32.06 g/mol). Then follow the same steps to calculate the grams of copper in the 165.0 g sample.

g) Hexaphosphorus pentasulfide has the chemical formula P6S5. Calculate the molar mass of P6S5 using the atomic masses of P (30.97 g/mol) and S (32.06 g/mol). Then follow the same steps as in Part 1 to calculate the grams of sulfur in the 125.5 g sample.