# Thermal Decomposition of Sodium Hydrogen Carbonate

Topics: Carbon dioxide, Sodium hydroxide, Sodium Pages: 3 (535 words) Published: May 3, 2009
Chemistry Write-Up
The Thermal Decomposition of Sodium Hydrogen Carbonate

Aim:
When Sodium Hydrogen Carbonate (NaHCO3) is heated, Carbon dioxide and water are given off to leave a white powder. The aim is to find the equations for this reaction.

Hypothesis:
The experiment will prove which of the equations below is true. It will tell us whether Sodium Carbonate is produced or Sodium Oxide.

2NaHCO3  Na2CO3 + CO2 + H2O

2NaHCO3  Na2O + 2CO2 + H2O

Variables:
Independent: Original Mass of NaHCO3

Dependant: Final Mass of the Residue

Controlled: Mass lost

Apparatus:

Method:
First we measured and recorded the weight of a crucible and its lid. Then we added some Sodium Hydrogen Carbonate into the crucible and measured and recorded the values again. After, we set up the apparatus as shown in Fig.1. We left the crucible over the fire for five minutes. Then we took it off and measured the weight of the Crucible and the residue. We then put it back on the fire to see if the weight would reduce further. This was repeated three times untill the compound was no longer reducing in weight.

Results:

Apparatus Weight (g)
Crucible and Lid 24.862
Crucible, Lid and NaHCO333.136
Original NaHCO38.274
Crucible, Lid and Residue 30.390
Residue5.528

2NaHCO3  Na2O + 2CO2 + H2O 168628818
10.370.52o.11
8.2743.054.330.89
Calculations:
2NaHCO3  Na2CO3 + CO2 + H2O 1681064418
10.630.260.11
8.2745.222.170.89

Conclusion:
The aim of the experiment was to find out which of the equations for the thermal decomposition on Sodium Hydrogen Carbonate is correct. This can be calculated by simply taking the Molecular formula of the reactants and products, then finding the ratio to one gram of the reactant. To find the mass of product I merely multiplied all the values by the original mass of Sodium Hydrogen...