onsider a tank used in certain hydrodynamic experiments. After one experiment the tank contains 200 L of a dye solution with a concentration of 1 g/L. To prepare for the next experiment, the tank is to be rinsed with fresh water flowing in at a rate of 2 L/min, the well-stirred solution flowing out at the same rate. Find the time that will elapse before the concentration of dye in the tank reaches 1% of its original value.

Explanation:

From the given information;

Let Q(t) = mass of dye in the tank as a function of time

The mass in the tank = 200 L × (1g/L) = 200 g

Using the law of mass conservation;

Q(0) = 200

By finding the solution to the ODE using the method of separation of variables;

Using the initial condition;

200 = Q(0) = C

1% of 200g = 2g of dye solution

∴

t = 460.5 hours

if two electrons have the same n, the same ℓ, and the same ml, then they are in the same orbital. the pauli exclusion principle states that no two identical fermions (a fancy word for electrons and other subatomic particles like electrons) may occupy the same quantum state in an atom simultaneously.

answer: enthalpy

explanation:

for a exothermic reaction, the energy is released i.e. the energy of the products is lower than the energy of the reactants.

= enthaply

= energy of products

= energy of reactants

as , thus comes out to be negative. negative value of enthalpy shows that the reaction is exothermic.