Zinc dissolves in acid according to the balanced equation.
Zn(s)+ 2H(aq)-> Zn(aq) + H2(g)
a sample of zinc is placed in a ice calorimeter. If 0.0657g of zinc causes a decrease of 0.109ml in the ice/water volume of the calorimeter, what is the enthalpy change, per mole of zinc, for the above reaction per mole of zinc.
To find the enthalpy change per mole of zinc for the given reaction, we need to determine the amount of moles of zinc that reacted and the corresponding change in enthalpy.
Step 1: Calculate the moles of zinc reacted.
First, we need to find the molar mass of zinc (Zn).
The molar mass of Zn is approximately 65.38 g/mol (you can find this value on the periodic table).
Given mass of Zn = 0.0657 g
Moles of Zn = Mass of Zn / Molar mass of Zn
Moles of Zn = 0.0657 g / 65.38 g/mol
Moles of Zn ≈ 0.001 mole (rounded to three decimal places)
Step 2: Calculate the change in volume.
Given change in volume = 0.109 ml
Since 1 ml is equal to 1 cm^3, the change in volume can be expressed as:
Change in volume = 0.109 cm^3
Step 3: Calculate the enthalpy change per mole of zinc.
The enthalpy change per mole of zinc can be determined using the equation:
Enthalpy change (ΔH) = (Volume change / Moles of Zn) x 22.4 L/mol
Where 22.4 L/mol is the molar volume of an ideal gas at standard temperature and pressure (STP).
ΔH = (0.109 cm^3 / 0.001 mole) x 22.4 L/mol
ΔH ≈ 2400 J/mol (rounded to the nearest whole number)
Therefore, the enthalpy change per mole of zinc for the given reaction is approximately 2400 J/mol.
To determine the enthalpy change per mole of zinc for the given reaction, we need to use the given mass of zinc and the volume change in the ice/water mixture.
First, let's calculate the moles of zinc used in the reaction:
Molar mass of zinc (Zn) = 65.38 g/mol
Moles of zinc = mass / molar mass = 0.0657 g / 65.38 g/mol
Next, we need to convert the volume change to liters:
Volume change = 0.109 ml = 0.109 ml * (1 L / 1000 ml)
Now, we can calculate the enthalpy change per mole of zinc:
Enthalpy change per mole of zinc = volume change / moles of zinc
Plug in the values and solve for the enthalpy change per mole of zinc.