The pressure of an ideal gas stays constant at 2.57 atm. This ideal gas has a volume of 45.8 mL when it is at a
temperature of 37.0°C. What temperature will this ideal gas
be at when it contracts to 32.5 mL?

the dissociation of nickel hydroxide is follows:

the concentration of hydroxide ion is

the equilibrium constant value of nickel hydroxide is = 6.1 * 10^-^1^6 and thus equilibrium equation can be written as:

thus, concentration of ni is 0.23 * 10^-^4 mol /l