When the gas is soluble, using a gas syringe is better than using a measuring cylinder. This is because a gas syringe is a closed system, which means that the gas cannot escape. This prevents the gas from dissolving in the water and affecting the accuracy of the measurement. A measuring cylinder is an open system, which means that the gas can escape. This can cause the gas to dissolve in the water and affect the accuracy of the measurement.

In addition, a gas syringe allows for more precise measurements than a measuring cylinder. This is because the gas syringe has a plunger that can be used to accurately control the volume of gas that is being measured. A measuring cylinder does not have a plunger, so it is more difficult to control the volume of gas that is being measured.

Therefore, when the gas is soluble, using a gas syringe is better than using a measuring cylinder.