A 10.0-L vessel contains gas A at a pressure of 300.0 torr. Gas A is forced into the second 3.00-L vessel. Calculate the resulting pressure in torr. Assume the temperature remains constant

i believe you are right for all except the 3rd ( look at sqdancefan his answer is much better)

the formula mass of a molecule or a compound is the sum of the atomic weights of the atoms in its empirical formula

(that's what i know about formula mass)

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

the objects have the same charge.