How much surfactant is needed for a spray tank with a capacity of 800 gallons at a concentration of 1/2%?

To determine the necessary amount of surfactant for an 800-gallon spray tank at a concentration of 1/2%, you need to perform a calculation based on the volume of the tank and the desired concentration.

First, convert the percentage concentration to a decimal. A concentration of 1/2% is equivalent to 0.005 in decimal form (1/2% = 0.5/100 = 0.005).

Next, multiply this decimal by the total volume of the spray tank:

0.005 (concentration) × 800 gallons (total volume) = 4 gallons of surfactant.

Therefore, 4 gallons of surfactant is the correct amount to achieve a concentration of 1/2% in an 800-gallon tank. This calculation helps ensure that the surfactant achieves the intended efficacy in improving the distribution and adherence of pesticide or herbicide applications, which is crucial for effective pest management. The other calculations for different amounts would yield incorrect concentrations based on the volume of the spray tank and the specified percentage.