Admin Table of Contents
- 1 What are some possible explanations for why the melting point of your isolated caffeine was lower than the literature value 236 C?
- 2 Why might the melting point of your isolated caffeine be lower than the literature value?
- 3 Does different kinds or types of tea produces different amount of caffeine content Why?
- 4 How do you determine the melting point of caffeine?
- 5 Is caffeine a carbonyl?
- 6 What determines caffeine content in tea?
What are some possible explanations for why the melting point of your isolated caffeine was lower than the literature value 236 C?
The melting point of your isolated caffeine is likely lower than the actual literature value because it contains impurities. The impurities can melt…
Why might the melting point of your isolated caffeine be lower than the literature value?
What are some possible explanations for why the melting point of you isolated caffeine was lower than the literature value(236 C)? it would require additional heat and some of the caffeine might decompose.
Why is it difficult to obtain caffeine melting point?
Some coffees may give caffeine samples melting at 190 to 2200C due to impurities. Be aware that caffeine is a material which can sublime (go directly from a solid to a gas phase), so rapid heating of your sample is necessary, and may cause difficulty in observing the melting point.
Why does caffeine have two carbonyl peaks?
The IR spectrum of caffeine contains two carbonyl peaks because caffeine is made up of two different carbonyl groups. Both peaks are due to an amide, with one amide frequency being higher than the other. Other than an alcohol a carboxylic group can also present itself at 3300 cm-1 as well as an amine group.
Does different kinds or types of tea produces different amount of caffeine content Why?
Caffeine occurs naturally in the tea plant, Camellia sinensis, so all brewed tea contains some caffeine. Hotter water and longer steeping time will draw out more caffeine in brewed tea—think black or oolong tea. Cooler water and shorter steeping time extracts less caffeine—think green or white tea.
How do you determine the melting point of caffeine?
According to both caffeine’s PubChem page and ChemSpider page its boiling point lies at 173 ∘C and its melting point at ∼235∘C.
What is the melting point of caffeine?
227 to 228 °C
Caffeine (data page)
| Names | |
|---|---|
| Appearance | Odorless, white needles or powder |
| Density | 1.23 g/cm3, solid |
| Melting point | 227 to 228 °C (441 to 442 °F; 500 to 501 K) (anhydrous) 234 to 235 °C (453 to 455 °F; 507 to 508 K) (monohydrate) |
| Boiling point | 178 °C (352 °F; 451 K) (sublimation) |
What is the literature melting point of caffeine?
235 °C
Is caffeine a carbonyl?
Caffeine is built up of two carbonyl groups and 4 tertiary amines. Both caffeine and theobromine also include an amide group, which is a functional group consisting of a carbonyl group bound to a C atom and a N atom, and an alkene, an unsaturated hydrocarbon containing at least one carbon-carbon double bond.
What determines caffeine content in tea?
The amount of caffeine in tea depends on a number of factors, including the method and length of brewing or steeping. Studies also show that leaf location on the tea plant affects content of caffeine in that tea. The youngest leaves, highest on the plant, contain the greatest concentration of caffeine AND antioxidants.
How is caffeine produced in tea?
Why is the melting point of caffeine not measured?
Be aware that caffeine is a material which can sublime (go directly from a solid to a gas phase), so rapid heating of your sample is necessary, and may cause difficulty in observing the melting point.