Measurement and Matter Setting up a unit conversion A student sets up the following equation to convert a measurement. (The? stands for a number the student is going to calculate.) Fill in the missing part of this equation. Note: your answer should be in the form of one or more fractions multiplied together. \[ \left(-6.7 \times 10^{4} \frac{\mathrm{J}}{\mathrm{mmol} \cdot{ }^{\circ} \mathrm{C}}\right) \cdot \square=? \frac{\mathrm{kJ}}{\mathrm{mol} \cdot{ }^{\circ} \mathrm{C}} \]

Step 1 ：The problem is asking to convert the units from Joules per millimole degree Celsius to kiloJoules per mole degree Celsius.

Step 2 ：To do this, we need to know the conversion factors: 1 kJ = 1000 J and 1 mol = 1000 mmol.

Step 3 ：So, the missing part of the equation should be the conversion factor that converts Joules to kiloJoules and millimoles to moles.

Step 4 ：Therefore, the missing part of the equation should be \(\frac{1 \, \text{kJ}}{1000 \, \text{J}} \times \frac{1000 \, \text{mmol}}{1 \, \text{mol}}\).

Step 5 ：Let's calculate the result of the equation with this conversion factor.

Step 6 ：The result of the calculation is -67.0, which is in the unit of kJ/mol°C. This is the same unit as the one we want to convert to, so the conversion factor is correct.

Step 7 ：Final Answer: The missing part of the equation is \(\boxed{\frac{1 \, \text{kJ}}{1000 \, \text{J}} \times \frac{1000 \, \text{mmol}}{1 \, \text{mol}}}\).