Final answer:
The remaining mass of the mixture after decomposition is 2.515 g. The percentage of NaHCO3 in the initial mixture can be found using stoichiometry and the ratio of molar masses. Sodium bicarbonate decomposes into sodium carbonate, water vapor, and carbon dioxide, typically between 50°C and 200°C.
Step-by-step explanation:
The question relates to thermal decomposition, specifically of sodium bicarbonate (NaHCO3), and involves calculations of the mass, percentage composition, identification of products, and investigation of decomposition temperature. Let's answer each part step by step:
- Calculate the remaining mass of the mixture: If we start with 2.968 g of the mixture and lose 0.453 g upon heating, the remaining mass will be 2.968 g - 0.453 g = 2.515 g.
- Determine the percentage of NaHCO3 in the initial mixture: We assume that the loss in mass (0.453 g) is due to the decomposition of NaHCO3 to Na2CO3, H2O, and CO2. The molar mass of NaHCO3 is approximately 84 g/mol, and that of CO2 is about 44 g/mol. Hence, for every 84 g of NaHCO3 that decomposes, 44 g of CO2 is released. By setting up a ratio, we can determine the original mass of NaHCO3 in the mixture: (84 g NaHCO3 / 44 g CO2) = (x g NaHCO3 / 0.453 g CO2). Solving for x gives us the mass of NaHCO3, from which we can then calculate the percentage by mass in the initial mixture.
- Identify the products formed during the thermal decomposition: The decomposition of sodium bicarbonate when heated produces sodium carbonate (Na2CO3), water vapor (H2O), and carbon dioxide (CO2).
- Investigate the temperature range at which the decomposition occurs: Sodium bicarbonate begins to decompose into sodium carbonate, water vapor, and carbon dioxide between 50°C and 200°C, with decomposition being most rapid above 100°C.