A 1.555 g sample of baking soda decomposes with heat to produce 0.991 g Na2CO3. What is the percent yield of sodium carbonate, Na2CO3?

Explanation:

Baking soda decomposes to produce sodium carbonate .

2NaHCO₃  = Na₂CO₃ + CO₂ + H₂O.

2 x 84 g          106 + 10 x 18  g

Molecular mass of Na₂CO₃ .10H₂O = 286

168 g baking soda  produces 286  g sodium carbonate

1.555g baking soda will produce 286 x 1.555 / 168

= 2.647 g

Percentage yield = actual yield / theoretical yield x 100

= ( .991 /2.647 ) x 100

= 37.43 %.

a polar bond is formed when electrons are shared unevenly between atoms

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.