Answer:
The time taken for the cross mark to disappear decreases steadily down the column.
Explanation:
Now if we look at the data provided, we will discover that the volume of the HCl was held constant while the volume of the thiosulphate was increased steadily and the volume of water decreased steadily.
Recall that a system is more concentrated when it contains less volume of water and more volume of reactants. Hence as the volume of water in the system is being reduced, the concentration of reactants is increased.
It has been established that an increase in the concentration of reactants lead to an increase in the rate of reaction. The disappearance of the cross shows the completion of the reaction between HCl and thiosulphate. The faster or slower the cross disappears, the faster or slower the rate of reaction.
Since increase in concentration of reactants increases the rate of reaction, it is observed that as the volume of the thiosulphate increases (reactant concentration increases) the cross disappears faster (rate of reactant increases). Hence as the volume of thiosulphate increases, it takes a shorter time for the cross to disappear. This implies that the time column in the table (refer to the question) will decrease steadily as the volume of thiosulphate increases.
Answer:
a)
b) entropy of the sistem equal to a), entropy of the universe grater than a).
Explanation:
a) The change of entropy for a reversible process:
The energy balance:
If the process is isothermical the U doesn't change:
The work:
If it is an ideal gas:
Solving:
Replacing:
Given that it's a compression: V2<V1 and ln(V2/V1)<0. So:
b) The entropy change of the sistem will be equal to the calculated in a), but the change of entropy of the universe will be 0 in a) (reversible process) and in b) has to be positive given that it is an irreversible process.
Answer:
c
Explanation:
Change in velocity over time
Answer:
Check the explanation
Explanation:
Lorenz force exerted on electron by magnetic field is
F=e*v*H, where e=1.602E-19 C, H=3.64E-3 T, v is speed of electron;
? meanwhile Lorenz force is centripetal force F=m*v^2/r, where mass of electron m=9.11E-31 kg, r is radius of the path of electron;
? therefore F=F; e*v*H = m*v^2/r; eH=m*(v/r), hence
v/r = eH/m =w is angular speed of electron, hence
T=2pi/w =2pi*m/(eH) is period of rotation of electron;
e- and e+ starting at the same point are moving in the same circular path and in opposite directions, and should meet in T/2 time;
T/2 = pi*m/(eH) = pi*9.11E-31 /(1.602E-19 *3.48E-3) =5.13E-9 s;