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Physical and chemical properties of various sugar water ratios for hummingbird feeders

Ross Dawkins
North American Bird Bander
4 (October - December)
Inland Regional News
Online Text:

Physical and chemical properties of various sugar water ratios for hummingbird feeders.

ROSS DAWKINS, Dept. Chem. & Biochem., Angela State University, San Angelo, TX.

Most people using sugar water for hummingbird feeders use a recipe ratio involving volumes of water (solvent) to volumes of dry granular sugar (solute) or they measure the final volume of the solution instead of added solvent. In either case it is not easy to compare one recipe to another as far as energy content or total amount of sugar. We have made up a series of sugar (sucrose, Imperial Pure Cane granulated) solutions using the percentage volumes of water and dry sugar. We have then measured the density, molarity, molality, calories/gal and freezing point of various ratios. Density (or the similar specific gravity) is measured easily in the field. The molarity (M) is a normalized method of measuring the moles of solute per volume of final solution. This makes comparisons between solutions easy. The molarity (m) measured the moles of solute per kilogram of solvent. This helps calculate colligative properties such as freezing point or boiling point of any solution. From the molarity, the number of calories/ gal can be calculated. This can be converted to calories or to joules easily. The results are in tabular form and interpolated into graphic form.

Table of Characteristics
V%water/ V% sugar Molarity M Molarity m Freezing Point (F) Density g/mL kCal/gal
33/67 (1:2) 2.31 4.97 15 1.256 11.96
50/50 (1) 1.58 2.485 24 1.174 8.18
60/40 (1.5:1) 1.20 1.66 26 1.132 6.21
67/33 (2:1) 0.965 1.24 28 1.107 5.00
75/25 (3:1) 0.695 0.828 29 1.077 3.60
80/20 (4:1) 0.543 0.621 30 1.058 2.81
File attachments
p-199.pdf (131.14 KB)

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