Answer:
1) a) 1.81 × 10²³ molecules (b) 1.93 × 10²³ molecules (c) 0.66× 10²³ molecules
2) a) 0.45× 10²³ions (b) 0.84× 10²³ions (c) 3.6 × 10²³ions
Explanation:
1) Number of molecules:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
a) 16g of H₂CO₃
Number of moles = mass/ molar mass
Number of moles = 16 g/ 62.03 g/mol
Number of moles = 0.3 mol
1 mol = 6.022 × 10²³ molecules
0.3 mol × 6.022 × 10²³ molecules /1 mol
1.81 × 10²³ molecules
b) 20g of HNO₃
Number of moles = mass/ molar mass
Number of moles = 20 g/ 63.01 g/mol
Number of moles = 0.32 mol
1 mol = 6.022 × 10²³ molecules
0.32 mol × 6.022 × 10²³ molecules /1 mol
1.93 × 10²³ molecules
c) 30g of C₆H₁₂O₆
Number of moles = mass/ molar mass
Number of moles = 20 g/ 180.156 g/mol
Number of moles = 0.11 mol
1 mol = 6.022 × 10²³ molecules
0.11 mol × 6.022 × 10²³ molecules /1 mol
0.66× 10²³ molecules
2. Calculate the number of ions in the following compounds:
a) 10g of AlCl₃
Number of moles = mass/ molar mass
Number of moles = 10g/ 133.34 g/mol
Number of moles = 0.075 mol
1 mol = 6.022 × 10²³ ions
0.075 mol × 6.022 × 10²³ ions/1 mol
0.45× 10²³ions
b) 30g of BaCl₂
Number of moles = mass/ molar mass
Number of moles = 30g/ 208.23 g/mol
Number of moles = 0.14 mol
1 mol = 6.022 × 10²³ ions
0.14 mol × 6.022 × 10²³ ions/1 mol
0.84× 10²³ions
c) 58 g of H2SO4
Number of moles = mass/ molar mass
Number of moles = 58g/ 98.079 g/mol
Number of moles = 0.59 mol
1 mol = 6.022 × 10²³ ions
0.59 mol × 6.022 × 10²³ ions/1 mol
3.6 × 10²³ions
Explanation:
