Question

one single dose of Maalox contains 500. mg each of Mg(OH)2 and Al(OH)3. how molecules of each compound are contained in a single dose?

Answer 1

To find the number of molecules, we need to find the number of moles of each compound

Number of moles = mass/Molar mass

Molar mass of Mg(OH)₂ = 58.32 g/mol

Molar mass of Al(OH)₃ = 78.01 g/mol

500 mg = 500/1000 = 0.5 g of Mg(OH)₂

Number of moles of Mg(OH)₂ = 0.5/58.32 = 0.0086 moles

Number of moles of Al(OH)₃ = 0.5/78.01 = 0.0064 moles

Number of molecules = number of moles*Avogadro's number

Number of molecules of Mg(OH)₂ = 0.0086*6.023*10²³ = 5.179*10²¹ molecules

Number of molecules of Al(OH)₃= 0.0064*6.023*10²³ = 3.855*10²¹ molecules