In intermolecular forces lab destroyed of the \"slime\" by adding sulfuric acid.
ID: 1066639 • Letter: I
Question
In intermolecular forces lab destroyed of the "slime" by adding sulfuric acid. Describe the chemistry that was taking place during his step. In the first kinetics experiment we were able to calculate a rate law and rate constant for the relationship between the concentration of crystal violet and the time (but in reality this was a pseudo rate constant) for the experiment because we did not actually include all of the reactants. Did the rate increase or decrease over time? Circle one. How is it that we were able to disregard the other reactant (OH) in our calculations? In the second kinetics experiment we used the method of initial rates to determine reaction order and examine reaction mechanism. Describe the effects of the catalyst and the change in temperature on the rate of reaction? Explain the basis for one of these effects using the Arrhenius equation. Do not explain math here. Explain the molecular basis for the effect.Explanation / Answer
4. Slime is destroyed by adding H2SO4
added H2SO4 gives H+ ion which are used for protonation of the -O-Si-O- oxygens, thereby cleaving the Si-O linkages, the Si gets substituted with OH from water and thus the slime intermolecular forces are broken apart.
5. In the rate law determination of crystal violet the rate of the reaction,
increases with time.
The [OH-] concentration is high enough that its concentration remains almost unchanged in the reaction and thus, the concentration of [OH-] does not affect the rate of the reaction and it becomes pseudo-first order reaction.
6. The catalyst when added enhances the initial rate of the reaction. The reaction also shows a gradual increase in the rate with increasing temperature as the collison factor increases with it, so more reactant collide with each other and form products.
Arrhenius equation relates, activation energy (Ea), rate constant (k) with temperature (T) and coilision factor A
k = Ae^(-Ea/RT)
So rate gets affected by change in temperature of the reaction.