Answer:
when the forward and reverse reactions occur at equal rates.
chemical reaction is in equilibrium when the concentrations of reactants and products are constant - their ratio does not vary.
There are 1.2 moles of KBr found in 3 Liters of 0.4 M solution.
<h3>HOW TO CALCULATE NUMBER OF MOLES?</h3>
The number of moles of a substance can be calculated by multiplying the molarity by the volume.
No. of moles = Molarity × volume
According to this question, 3L of a KBr solution are contained in a 0.4M.
no. of moles = 3L × 0.4M = 1.2moles
Therefore, there are 1.2 moles of KBr found in 3 Liters of 0.4 M solution.
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Answer: X is a Solid; Y is a Gas
Explanation:
There are three (3) states of matter. They are: Solid, Liquid and Gases.
Substance X and Y, belong to the states of matter.
A Solid is a substance that retains its SIZE and SHAPE without need of a container (as opposed to a liquid or gas).
Thus, it will most likely be concluded that: substance X is a Solid; while Y is a Gas
Answer : The work done by the system is, 2.2722 J
Explanation :
The expression used for work done in reversible isothermal expansion will be,

where,
w = work done = ?
n = number of moles of gas = 0.00100 mole
R = gas constant = 8.314 J/mole K
T = temperature of gas = 
= initial volume of gas = 25 mL
= final volume of gas = 75 mL
Now put all the given values in the above formula, we get:


Therefore, the work done by the system is, 2.2722 J