Calculate the theoretical mass of sodium carbonate solid that should be produced by heating 1.678 grams of sodium bicarbonate.

The chemical symbol for sodium bicarbonate is NaHCO₃. Its molar mass is calculated by adding the product of the molar mass of each of the component and the number of moles. That is,

   molar mass of NaHCO₃ = (1 mol Na)(23 g Na/1 mol Na) + (1 mol H)(1 g H/ 1 mol H) + (1 mol C)(12 g C/1 mol C) + (3 mol O)(16 g O/1 mol O)
    molar mass of NaHCO₃ = 84 g/mol

Same is to be done with sodium carbonate which has a molar mass of Na₂CO₃
  molar mass of Na₂CO₃ = (2 mol Na)(23 g Na/1 mol Na) + (1 mol C)(12 g C/1 mol C) + (3 mol O)(16 g O/1 mol O)
   molar mass of Na₂CO₃ = 106 g/mol

The decomposition of sodium bicarbonate to sodium carbonate is shwon below,
    2NaHCO₃ --> Na₂CO₃ + H₂O + CO₂

Through conversion factors and dimensional analysis,
 (1.678 g NaHCO₃)(1 mol NaHCO₃/84 g NaHCO₃)(1 mol Na₂CO₃/2 mol NaHCO₃)(106 g NaHCO₃/1 mol NaHCO₃)
     = 1.06 g Na₂CO₃

ANSWER: 1.06 g Na₂CO₃

The most plausible answer is b, duration. the given amount of time is considered how long it last for.