Answer:
Experiments to determine mechanisms involve looking at indirect evidence to help support or disprove a proposed mechanism.
Most intermediates are not typically isolated to determine reaction mechanisms.
Carbocations are very reactive and are typically not isolated for analysis.
Scientists can prove that a specific mechanism exists.
Evidence of intermediates sometimes can be seen using techniques such as nuclear magnetic resonance spectroscopy
Explanation:
The study of reaction mechanism and chemical kinetics often form the main thrust of study in organic, inorganic and physical chemistry.
We often want to know the actual processes involved in the conversion of one specie to another. Unfortunately, this information may have to be obtained indirectly by certain chemical reactions or by the use of new instrumental methods such as nuclear magnetic resonance spectroscopy.
Many organic reactions have carbocation intermediates. These carbocations are relatively short-lived and are transient intermediates which are rarely isolated unless they are isolated in a molecular cage using a macromolecule or in superacids.
By intensive study, scientists can proof or disprove the authenticity of any proposed mechanism.
We must know that a transition state has partial bonds. It is often an extremely short-lived specie which cannot be isolated.
The change in pressure over a given distance is defined as a pressure gradient. The strength of this pressure gradient determines how fast the wind moves from higher pressure toward lower pressure. A stronger pressure gradient will cause stronger winds, as shown in Figure 2. >> Balanced in the vertical by the force of gravity
there are valence electrons 3 in group 10.
Balance the equation first:
2 Fe+6 HNO3→2 Fe(NO3)3+3H2
Then calculate mass of Iron :
4.5×3.0×3.5 cm3(1 mL1 cm3)(7.87 g Fe1 ml)=371.86 g Fe
Now use Stoichiometry:
371.86 g Fe×(1 mol Fe55.85 g Fe)×(6 mol HNO32 mol Fe)=19.97 mol HNO3
Convert moles of nitric acid to grams
19.97 mol HNO3×(63.01 g HNO31 mol HNO3)=1258.3 g HNO3
OK in the case of hydrazine 14 grams of nitrogen combine with 2 gram of hydrogen and with ammonia 14 grams combine with 3 grams of hydrogen.
Ratio 2:3
