Question

In order to prepare turpentine oil emulsion, the quantities of oil, water and gum in the primary emulsion formulation is

• A. 4:2:1
• B. 3:2:1
• C. 2:2:1
• D. 1:2:1

Hint:

The stability of emulsions depends on the correct ratio of oil, water, and gum. The typical ratio for turpentine oil emulsion is 3:2:1.

Answer 1

The Correct Option is B

The dry gum (continental) method for preparing a primary emulsion follows fixed oil:water:gum proportions that vary by the oil's nature. For turpentine oil, the ratio used to form the primary emulsion (nucleus) before further dilution is 3 parts oil, 2 parts water and 1 part gum, i.e. 3:2:1. This proportion gives the gum enough water to hydrate fully while still allowing the oil to be incorporated into a stable primary emulsion that can later be diluted to the required volume.

Therefore, the correct answer is 3:2:1.

Answer 2

A useful way to approach this is to notice that in the dry gum method, the water:gum ratio is fixed at 2:1 across nearly all standard formulations, so the differentiating factor between the options is only the amount of oil. Let's check each option on this basis.

1. 4:2:1: Keeps the water:gum ratio at 2:1, but assigns the highest amount of oil, which fits thicker fixed oils rather than turpentine oil.
2. 3:2:1: Also keeps the water:gum ratio at 2:1, with a moderate oil proportion, matching the amount conventionally used for turpentine oil in the primary emulsion.
3. 2:2:1: Maintains the 2:1 water:gum ratio but lowers the oil further, a proportion generally used for oils requiring an even smaller nucleus.
4. 1:2:1: Breaks from the expected pattern by giving oil the smallest share, more water than oil, which is inconsistent with how a primary emulsion is meant to concentrate the oil phase.

Since the water:gum ratio stays constant at 2:1 in all valid formulations, the distinguishing choice comes down to the oil quantity, and the value used for turpentine oil is 3.

Therefore, the correct answer is 3:2:1.