Final answer:
To calculate the mass of sodium hydroxide in the solution, we need to calculate the number of moles of sodium hydroxide and then multiply it by the molar mass of NaOH. Given the volume of the solution and the concentration, we can calculate the number of moles using the formula moles = volume x concentration. The number of moles is then multiplied by the molar mass of NaOH to obtain the mass of sodium hydroxide.
Step-by-step explanation:
To calculate the mass of sodium hydroxide in the solution, we first need to calculate the number of moles of sodium hydroxide present. The formula for calculating the number of moles is:
Moles = volume (dm³) x concentration (mol/dm³)
Given that the volume is 30 cm³ and the concentration is 0.105 mol/dm³, we convert the volume to dm³ by dividing it by 1000:
30 cm³ = 30/1000 dm³ = 0.03 dm³
Substituting the values into the formula:
Moles = 0.03 dm³ x 0.105 mol/dm³ = 0.00315 mol
To calculate the mass, we use the molar mass of sodium hydroxide. The molar mass of NaOH is 22.99 g/mol for sodium, 15.999 g/mol for oxygen, and 1.008 g/mol for hydrogen. Adding these up:
22.99 g/mol + 15.999 g/mol + 1.008 g/mol = 40.997 g/mol
Finally, we multiply the number of moles by the molar mass:
Mass = number of moles x molar mass = 0.00315 mol x 40.997 g/mol = 0.129 g