Final answer:
The pH of the solution cannot be determined without additional information.
Step-by-step explanation:
The given question states that 1.88g of Cu(NO3)2 undergoes complete thermal decomposition, producing a gas that dissolves in water to form a 2 L solution labeled as A. The student wants to know the pH of solution A.
First, we need to calculate the molar mass of Cu(NO3)2. It is 63.55 g/mol for Cu + (14.01 + 3 x 16.00) g/mol for NO3 = 125.55 g/mol for Cu(NO3)2.
The number of moles of Cu(NO3)2 can be calculated as 1.88 g / 125.55 g/mol = 0.01499 mol. This is also equal to the number of moles of Cu²+ ions present in the solution, as Cu(NO3)2 completely ionizes in water.
The presence of the Cu²+ ions makes the solution acidic. The exact pH of the solution cannot be determined without knowing the concentration of Cu²+ ions, as it would depend on factors such as the volume of water and the dissociation constant of Cu²+ in water. Therefore, to determine the pH, we need additional information.