First two hw of 50 that I am trying to get a handle on. Any help would be appreciated.
3.What gaseous substance is driven off of succrose when it is heated?
is the answer CO2?
7.What gaseous substance is driven off of succrose when it is reacted with acid?
17. What is the back residue left over after complete dehydration of a carbohydrate?
a. C b. SO2 c. HSO2 d. H20
3. If heated to a high temperature, the carbon will burn giving CO2; however, I think the problem refers to a more gentle heating. In that case it will drive off water (which at the temperature of a burner will be a gas) leaving carbon.
7. What acid. With H2SO4, it is dehydrated leaving carbon and the reaction gets hot enough to vaporize the water. If treated with chloric acid (HClO3), CO2, H2O, and HCl are produced.
17. Did you mean "black" residue? carbon.
Thanks for the reply. Question does not specify which acid. There are a min. of ten other questions that just state 'acid', which makes it more confusing.
yes, 'black' residue.
To answer question 3, you need to know the chemical composition of sucrose and understand the process of heating it. Sucrose is a sugar commonly found in plants, and its chemical formula is C12H22O11. When sucrose is heated, it undergoes a process called thermal decomposition. During this process, sucrose breaks down into its component parts, which includes carbon dioxide gas (CO2) as one of the products. Therefore, the correct answer to question 3 is CO2.
To answer question 7, you need to understand the reaction between sucrose and acid. When sucrose reacts with an acid, it undergoes a chemical reaction known as hydrolysis. This reaction involves the breaking of chemical bonds in the sucrose molecule by the presence of water and an acid catalyst. The hydrolysis of sucrose produces glucose and fructose, which are both monosaccharides. It does not produce any gaseous substance. Therefore, there is no gaseous substance driven off of sucrose when it is reacted with acid.
To answer question 17, you need to understand the concept of complete dehydration of a carbohydrate. Dehydration refers to the removal of water molecules from a substance. When a carbohydrate undergoes complete dehydration, it loses all its water molecules. The residue left over after this process is complete would not contain water anymore. Among the options given, the only one that does not include water is option a) C. Therefore, the correct answer to question 17 is a) C.