1.) Calculate the number of atoms in 2.58 mol antimony.

2.) Determine the mass of 1.45 mol FePO4.

3.) Calculate the number of mol in 6.75 g of NaCl.

4.) What is the volume, in liters, of 2.54 mol methane (CH4) gas?.

5.) What is the percent composition of B4H10?

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1.) To calculate the number of atoms in 2.58 moles of antimony, you can use Avogadro's number, which states that there are 6.022 × 10^23 atoms in one mole of any substance.

First, you need to find the molar mass of antimony (Sb), which is 121.76 g/mol.

Next, you multiply the number of moles (2.58 mol) by Avogadro's number (6.022 × 10^23 atoms/mol).

Number of atoms = 2.58 mol × 6.022 × 10^23 atoms/mol

2.) To determine the mass of 1.45 moles of FePO4, you need to find the molar mass of FePO4.

The molar mass of FePO4 is calculated by adding up the atomic masses of its constituent elements:
Fe (iron) = 55.85 g/mol
P (phosphorus) = 30.97 g/mol
O (oxygen) = 16.00 g/mol (there are 4 oxygen atoms in FePO4)

Molar mass of FePO4 = (1 × 55.85 g/mol) + (1 × 30.97 g/mol) + (4 × 16.00 g/mol)

To find the mass of 1.45 moles, you multiply the molar mass by the number of moles:
Mass = 1.45 mol × (molar mass of FePO4)

3.) To calculate the number of moles in 6.75 g of NaCl (sodium chloride), you need to know the molar mass of NaCl.

The molar mass of NaCl can be found by adding up the atomic masses of its constituent elements:
Na (sodium) = 22.99 g/mol
Cl (chlorine) = 35.45 g/mol

Molar mass of NaCl = 22.99 g/mol + 35.45 g/mol

To find the number of moles, you divide the mass of NaCl by its molar mass:
Number of moles = 6.75 g ÷ (molar mass of NaCl)

4.) To calculate the volume of 2.54 moles of methane gas (CH4), you can use the ideal gas law equation: PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant (0.0821 L•atm/mol•K), and T is the temperature in Kelvin.

Assuming constant temperature and pressure, the equation can be rearranged to solve for volume (V):
V = (nRT) / P

Given that you have the number of moles (2.54 mol), the ideal gas constant (0.0821 L•atm/mol•K), and the values of temperature and pressure, you can substitute them into the equation to find the volume.

5.) To calculate the percent composition of B4H10 (diborane), you need to determine the total molar mass of the compound and the molar mass of each element present.

The molar mass of B4H10 can be calculated by adding up the atomic masses of boron (B) and hydrogen (H).

Boron's molar mass = 10.81 g/mol
Hydrogen's molar mass = 1.01 g/mol

Molar mass of B4H10 = (4 × Boron's molar mass) + (10 × Hydrogen's molar mass)

Then, you can calculate the percent composition of each element by dividing the molar mass contribution of each element by the total molar mass of B4H10 and multiplying by 100%.

Percent composition of B = (Molar mass contribution of B / Molar mass of B4H10) × 100%
Percent composition of H = (Molar mass contribution of H / Molar mass of B4H10) × 100%