Area of a deck is 680 square feet. the deck's width is 17 feet. what is its perimeter

First you need to find the length

L=680/17=40

Then you would add all 4 sides together (I'm assuming that the deck is a rectangle as you gave the width and area and the area formula using width is A=LW)

17+17+40+40=114

The deck's perimeter is 114ft

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