The process that is an example of a chemical change would be of ice turning into water when heated over a Bunsen Burner.
Rates can be calculated with Arrhenius equation k = Axe^(-Ea/RT)
a. temperature affects the rate - imagine you are making coffee, so coffee crystals are boiled faster on higher temperature. Simplified but makes sense.
b. Ea is activation energy. Imagine, while preparing coffee, some of ingredients change to a different one, so there is a A -> B reaction (simplified). Now, Ea is energy barrier that stands on the arrow of this reaction, preventing A to transform to B. If Ea is small, reaction will go easy (not fast!), if Ea is large –reaction will not happen so easy (you ll have to use catalyst for example)
When Cr+3 + 3e- → Cr(s)
So according to the charge formula:
charge Q = I * t
when we have I (the current) = 7.4 a
and t (the time in seconds) = 1.85d * 24h * 60 min*60sec= 159840 sec
by substitution:
Q = 7.4 a * 159840 sec = 1182816 C
now to get the mass we have to use Faraday constant which is:
F = e NA
= 1.602 x 10^-19 * 6.022 x 10^23
= 96485 C mol^-1
when e is the electron charge & NA Avogadro's number for the charge in on mol
and as we can see from the equation Cu3+ reacts with 3 electrons so,
the mass of Cr(s) = Q* (1mole-/F) * (1molCr / 3 mol e-)
= 1182816 * (1/96485) * (1/3)
= 4.1 g
32*x + (1-x) * 36 =33
32x _36-36x =33
-4x = -3
x=.75
Hope this helps
Answer:
Explanation:
Solids have a fixed shape and occupy a fixed volume. because the particles in liquid are so close together,liquids do'not easily compress,so their volume is fixed. gases can also flow, so they occupy the shape of the whole container.
