Compounds W and X react together to form an equilibrium mixture containing compounds Y and Z according to the equation:
2W(aq)+X(aq)⇌3Y(aq)+Z(aq) 2\text{W}(\text{aq}) + \text{X}(\text{aq}) \rightleftharpoons 3\text{Y}(\text{aq}) + \text{Z}(\text{aq}) 2W(aq)+X(aq)⇌3Y(aq)+Z(aq)A beaker contained 80 cm380\text{ cm}^380 cm3 of a 0.15 mol dm−30.15\text{ mol dm}^{-3}0.15 mol dm−3 aqueous solution of W. 2.5×10−2 mol2.5 \times 10^{-2}\text{ mol}2.5×10−2 mol of X and 3.0×10−2 mol3.0 \times 10^{-2}\text{ mol}3.0×10−2 mol of Y were added to the beaker and the mixture was left to reach equilibrium. The equilibrium mixture formed contained 4.0×10−3 mol4.0 \times 10^{-3}\text{ mol}4.0×10−3 mol of W.
Calculate the amounts, in moles, of X, Y and Z in the equilibrium mixture.
Give the expression for the equilibrium constant (KcK_cKc) for this equilibrium and its units.
A different equilibrium mixture of these four compounds, at a different temperature, contained 0.36 mol0.36\text{ mol}0.36 mol of XXX, 0.64 mol0.64\text{ mol}0.64 mol of YYY and 0.080 mol0.080\text{ mol}0.080 mol of ZZZ in a total volume of 5.00×102 cm35.00 \times 10^2\text{ cm}^35.00×102 cm3 of solution. At this temperature the numerical value of KcK_cKc was 585858.
Calculate the concentration of W, in mol dm−3\text{mol dm}^{-3}mol dm−3, in this equilibrium mixture. Give your answer to the appropriate number of significant figures.
Justify the statement that adding more water to the equilibrium mixture in Part 3 will lower the amount of W in the mixture.
