Answer:
- Starch is a polysaccharide comprising glucose monomers joined in α 1,4 linkages. or
- Starch is a long-chain polymer of glucose molecules joined together. or
- A starch is a complex polysaccharide made up of a large number of glucose units joined together by glycosidic bonds.
Explanation:
starch, a white, granular, organic chemical that is produced by all green plants. Starch is a soft, white, tasteless powder that is insoluble in cold water, alcohol, or other solvents.
Starch is amongst the most abundant plant products and is a mixture of two polymers, amylose and amylopectin. During food processing starch is transformed by hydrothermal treatments. ... The structure of starch is also influenced by specific and non-specific interactions with other food constituents and ingredients.
Answer:The mechanism of the formation of 4-nitrophenyl phenyl ether include the electrophilic substitution in phenol and the nitration of chlorobenzene.
Explanation:
To prepare the 4-nitrophenyl phenyl ether appropriate equivalent of aqueos NaOH is added to absolute phenol, dissolved gives a Phenoxide ion aqueous and is then added.
After the addition of the appropriate mole of chlorobenzene, to the mixture of HNO3 and H2SO4 is heated under reflux with stirring and exclusion of moisture for 5 hours. The alcohol is distilled off from the reaction mixture to a substantial extent through a 20-cm Vigreux column with stirring and the cooled distillation residue is poured into 100 ml of 5% caustic sodium carbonate; the organic phase is extracted several times with diethyl ether, washed with water, and dried with calcium chloride; the solvent is distilled off, and the residue is fractionated or recrystallized from ethanol. Unchanged phenol can be recovered by acidifying the aqueous alkaline solution and extracting it with ether.
The yield of 4-nitrophenyl phenyl ether 80%, m.p. 40°C; b.p. 286-287 °C; in the presence of HNO3 and H2SO4
You need to use the ideal gas equation:
P is pressure (in atm or bar)
V is volume (in L)
n is the number of moles (in mol)
R is an experimentally determined ratio of about 0.82
T is the temperature (in Kelvin)
Note:
For all gases, you need to convert Celsius or Fahrenheit to Kelvin.Get V alone.
Plug in the values you have.
you get:
A fun fact: the gas used to fill up a balloon is Helium.
When oxygen is found is peroxide, it has an oxidation number of -1.
The chemical formula of hydrogen peroxide is H2O2. We know that hydrogen always has +1 oxidation state until it forms metal hydrides. So in H2O2, the oxidation state ofhydrogen is +1.
Now, let oxidation state of oxygen be x. So,
2 * (+1) + 2*x = 0
2 + 2x = 0
2x = -2
x = -2 / 2
x = -1
Hence, the oxidation number of oxygen in peroxides is -1
Answer: The bond formed between magnesium and oxygen is an ionic bond.
Explanation:
An ionic bond is formed when an atom transfer its valence electrons to another atom.
Whereas, a covalent bond is formed by the sharing of electrons between the atoms.
Silicon and oxygen forms silicon dioxide. Silicon has 4 valence electrons which are shared with each oxygen atom. Hence, silicon and oxygen forms a covalent bond.
Oxygen and oxygen shares two pairs of electrons therefore, a covalent bond is formed between oxygen and oxygen.
A covalent bond is formed between carbon and hydrogen as carbon has 4 valence electrons which are shared with four hydrogen atoms.
Magnesium has 2 valence electrons which are transferred to the oxygen atom in order to complete its octet.
Therefore, the bond formed between magnesium and oxygen is an ionic bond.