Chm Lab
How Much Sodium Bicarbonate Is In the Mixture?
Lab Investigation 14
Chemistry 113 Lab
10/13/2011
1) Method 1: Adding acid
NaHCO3 + HCl → NaCl + CO2 + H2O
a) Unknown mixture of NaCl and NaHCO3 Mass of unknown mixture (NaCl + NaHCO3) | 3 g | Mass of HCl | 30 .31g | Mass of products ( NaCl + H2O ) | 26.98 g | Calculate mass of CO2 | 6.33g | Calculate mass of NaHCO3 | 12 .1 g |
i) Calculation :
Mass of CO2 =
[Mass of unknown mixture (NaCl + NaHCO3) + Mass of HCl ] – [Mass of NaCl + H2O]
= (3 g + 30.31 g) – 26.98 g = 6.33g
Mass of NaHCO3 :
6.33 g CO2 * 1 mol CO2 44.10 g CO2 * 1 mol NaHCO3 1 mol CO2 *84.20 g NaHCO3 1mol NaHCO3 =12. 1 g NaHCO3
b) Purity sodium bicarbonate Mass of NaHCO3 | 3 g | Mass of HCl | 30 g | Mass of products ( NaCl + H2O ) | 26.81 g | Calculate mass of CO2 | 6. 19 g | Theoretical mass of NaHCO3 | 11. 8 g |
i) Calculation :
Mass of CO2 = ( Mass of NaHCO3 + Mass of HCl ) – ( Mass of NaCl + H2O )
= (3 g + 30 g ) – 26.81 g = 6.19 g
Theoretical mass of NaHCO3 :
6.19 g CO2 * 1 mol CO2 44.10 g CO2 * 1 mol NaHCO3 1 mol CO2 *84.20 g NaHCO3 1mol NaHCO3 =11. 8 g NaHCO3
2) Method 2: Heating 2NaHCO3→Na2CO3+CO2+H2O
a) Experimental results
i) Trial 1 Mass of NaHCO3 | 0.3g | Temperature of hot plate | 400 ˚C | Time interval | 10 min. | Mass of mini beaker and product (Na2CO3) | 31.3g | Mass of mini beaker | 31.21g | Final mass of Na2CO3 | 0.09g |
ii) Trial 2 Mass of NaHCO3 | 0.3g | Temperature of hot plate | 400 ˚C | Time interval | 10 min. | Mass of mini beaker and product (Na2CO3) | 31.52g | Mass of mini beaker | 31.31g | Final mass of Na2CO3 | 0.21g |
iii) Average mass of Na2CO3
(0.09 g + 0.21 g) / 2 = 0.15 g
b) Theoretical results
i) Trial 1
0.3g NaHCO3 * 1mol NaHCO384.0062g NaHCO3 * 1 mol Na2CO32 mol NaHCO3 * 105.99g Na2CO31 mol Na2CO3 = 0.19g Na2CO3
2) Trial 2
0.3g NaHCO3 * 1mol NaHCO384.0062g NaHCO3 * 1 mol Na2CO32 mol NaHCO3 * 105.99g Na2CO31 mol Na2CO3
Lab Investigation 14
Chemistry 113 Lab
10/13/2011
1) Method 1: Adding acid
NaHCO3 + HCl → NaCl + CO2 + H2O
a) Unknown mixture of NaCl and NaHCO3 Mass of unknown mixture (NaCl + NaHCO3) | 3 g | Mass of HCl | 30 .31g | Mass of products ( NaCl + H2O ) | 26.98 g | Calculate mass of CO2 | 6.33g | Calculate mass of NaHCO3 | 12 .1 g |
i) Calculation :
Mass of CO2 =
[Mass of unknown mixture (NaCl + NaHCO3) + Mass of HCl ] – [Mass of NaCl + H2O]
= (3 g + 30.31 g) – 26.98 g = 6.33g
Mass of NaHCO3 :
6.33 g CO2 * 1 mol CO2 44.10 g CO2 * 1 mol NaHCO3 1 mol CO2 *84.20 g NaHCO3 1mol NaHCO3 =12. 1 g NaHCO3
b) Purity sodium bicarbonate Mass of NaHCO3 | 3 g | Mass of HCl | 30 g | Mass of products ( NaCl + H2O ) | 26.81 g | Calculate mass of CO2 | 6. 19 g | Theoretical mass of NaHCO3 | 11. 8 g |
i) Calculation :
Mass of CO2 = ( Mass of NaHCO3 + Mass of HCl ) – ( Mass of NaCl + H2O )
= (3 g + 30 g ) – 26.81 g = 6.19 g
Theoretical mass of NaHCO3 :
6.19 g CO2 * 1 mol CO2 44.10 g CO2 * 1 mol NaHCO3 1 mol CO2 *84.20 g NaHCO3 1mol NaHCO3 =11. 8 g NaHCO3
2) Method 2: Heating 2NaHCO3→Na2CO3+CO2+H2O
a) Experimental results
i) Trial 1 Mass of NaHCO3 | 0.3g | Temperature of hot plate | 400 ˚C | Time interval | 10 min. | Mass of mini beaker and product (Na2CO3) | 31.3g | Mass of mini beaker | 31.21g | Final mass of Na2CO3 | 0.09g |
ii) Trial 2 Mass of NaHCO3 | 0.3g | Temperature of hot plate | 400 ˚C | Time interval | 10 min. | Mass of mini beaker and product (Na2CO3) | 31.52g | Mass of mini beaker | 31.31g | Final mass of Na2CO3 | 0.21g |
iii) Average mass of Na2CO3
(0.09 g + 0.21 g) / 2 = 0.15 g
b) Theoretical results
i) Trial 1
0.3g NaHCO3 * 1mol NaHCO384.0062g NaHCO3 * 1 mol Na2CO32 mol NaHCO3 * 105.99g Na2CO31 mol Na2CO3 = 0.19g Na2CO3
2) Trial 2
0.3g NaHCO3 * 1mol NaHCO384.0062g NaHCO3 * 1 mol Na2CO32 mol NaHCO3 * 105.99g Na2CO31 mol Na2CO3