Salt or Soda?

Lailani Lewis

Ms. Adams

4^th Grade

February 8, 2017

 

 

 

 

Question

Which dissolves better in water salt or baking soda?

 

 

Hypothesis

If I put water and salt in one cup and water and baking soda in another, then salt will dissolve better.

 

 

 

 

Bibliography

• https://prezi.com/7vl6dcj3y-gy/salt-or-baking-soda/
• https://www.reference.com/science/dissolves-better-water-salt-baking-soda-d5d899876594eaf1

 

 

 

 

Background Information

 Table salt is more soluble in water than baking soda because of the difference in polarity, bond types and compound size. Salt, or sodium chloride, is bound by ionic bonds and is considered extremely polar. Water, or H2O, is also very polar.

When sodium chloride, or NaCl, is dissolved in water, it is easily broken into individual Na+and Cl-ions.

Baking soda, or sodium bicarbonate, consists of a Na+ ion bound to a larger bicarbonate ion.  Although this compound is polar, it is less polar than sodium chloride.  This means it is less soluble than NaCl. Also, although the Na+ ions easily disassociate in a polar solvent such as water, the bicarbonate ion never truly dissolves. Bicarbonate, or HCO3-, is an organic molecule composed of covalent bonds. Covalent compounds do not dissolve in polar solvents. The HCO3- ion takes a hydrogen atom from water to form carbonic acid, which then decomposes to form CO2 gas and water.

 

 Procedures

 

1. Gather my materials
2. Fill both cups with 8 ounces of water
   3. Put 2 teaspoons of salt in one cup and stir 5 times
   4. Put 2 teaspoons of baking soda in the other cup and stir 5 times
   5. Look to see which one dissolved
3. Record results
4. Repeat steps 2-6 two more times
5. Record results

Materials

 

• 2 plastic 12 ounce cups
• Salt
• Baking soda
• Water
• A spoon
• Measuring cup
• Teaspoon

Conclusion

 

Based on my results I found out that my hypothesis was incorrect. Baking soda dissolved better than salt in water after stirring 5 times and waiting for about 5 minutes. In each trial baking soda dissolved better because it was clearer to see through than the salt was. Based on my results I learned that the amount of water and salt or baking soda might affect which dissolves better. I also learned that baking soda takes less time to dissolve than salt.

 

DATA/ RESULTS

 

Trials	Amount	Water	Time	Results
Trial 1
Baking Soda	2 tsp	12 oz.	5 Min.	Clear
Salt	2 tsp	12 oz.	5 Min.	Cloudy
Trial 2
Baking Soda	2 tsp	12 oz.	5 Min.	Clear
Salt	2 tsp	12 oz.	5 Min.	Cloudy
Trial 3
Baking Soda	2 tsp	12 oz.	5 Min.	Clear
Salt	2 tsp	12 oz.	5 Min.	Cloudy