Answer:
1. number of Cd atoms = 4.384 × 10²³
2. number of moles of Ti = 0.817 mol
3. molar mass of C₇H₆O₃ = 138.077 g/mol
4. moles of Sildenafil = 0.249 mmol
Explanation:
1. given data
mass of Cd = 81.8 g
number of Cd atoms = ?
molar mass of Cd = 112.411 g/mol
Solution
1st we find out the number of moles of Cd
<em> number of moles = mass / molar mass
</em>
number of moles of Cd = 81.8 g / 112.411 g.mol⁻
number of moles of Cd = 0.728 mol
Now we find out the number of Cd atoms
<em> number of atoms = moles × 6.022 × 10²³</em>
number of Cd atoms = 0.728 (6.022 × 10²³)
number of Cd atoms = 4.384 × 10²³
2. Given data
Mass of Ti = 39.1 g
moles = ?
molar mass Ti = 47.867 g/mol
Solution
Now we will find out the number of moles
<em> number of moles = mass / molar mass
</em>
number of moles of Ti = 39.1 g / 47.867 g.mol⁻
number of moles of Ti = 0.817 mol
3. Given data
chemical formula of Salicylic acid = C₇H₆O₃
molar mass of salicylic acid = ?
molar mass of carbon = 12.011
molar mass of hydrogen = 1.008
molar mass of oxygen = 15.999
<em> molar mass of molecule = number of moles of atoms × molar mass of atoms</em>
molar mass of C₇H₆O₃ = 7 (12.011) + 6 (1) + 3 (16)
molar mass of C₇H₆O₃ = 84.077 g + 6 g + 48 g
molar mass of C₇H₆O₃ = 138.077 g/mol
4. Given data
molar mass of Sildenafil = 474.5828 g/mol
mass given = 0.118 g
moles of Sildenafil = ?
Solution
Now we find out the number of moles
<em> number of moles = mass / molar mass
</em>
<em> </em>number of moles Sildenafil = 0.118 g / 474.5828 g/mol
number of moles Sildenafil = 0.0003 mol
as this is very small amount we convert it into millimoles
<em>millimoles = moles × 1000</em>
millimoles of Sildenafil = 0.000249 × 1000
millimoles of Sildenafil = 0.249 mmol
