Cwea Grade 4 Test Part 2 Questions and Answers 100% Correct(GRADED A+)

Acid: - ANSWER-A substance which releases hydrogen ions when dissolved in water. Most acids will dissolve the common metals and will react with a base to form a neutral salt and water. An acid is the opposite of an alkali, has a pH rating lower than 7.0, will turn litmus paper red, and has a sour taste. Acidity: - ANSWER-The quantitative capacity of water or a water solution to neutralize an alkali or base. It is usually measured by titration with a standard solution of sodium hydroxide, and is expressed in ppm or mg/L of its calcium carbonate equivalent. Accuracy: - ANSWER-The difference between the readings of an instrument and true value of what is being measured, expressed as a percent of full instrument scale. Air Gap: - ANSWER-A clear vertical space through the free atmosphere, between the lowest opening of any pipe or faucet conveying water or waste to a tank plumbing fixture receptor or other device, and the flood level rim of the receptacle. An air gap is used to prevent cross connection between a water treatment device and a possible source of wastewater, thereby preventing a reverse flow of water from the sewer into the water supply system. Without an air gap, such reverse flow could occur due to an increase in the pressure in the sewer system or the creation of a negative pressure in the water supply line. Local plumbing codes usually require the air gap to be twice the diameter of the inlet, with a minimum width of 1.5 inches. Alternating current (AC Power): - ANSWER-Electrical current that alternates direction in cycles called hertz. American Wire Gage (AWG): The U.S. standard for wire size. Alkalinity: - ANSWER-The quantitative capacity of water to neutralize an acid; that is, the measure of how much acid can be added to a liquid without causing a significant change in pH. Alkalinity is not the same as pH because water does not have to be strongly basic (high pH) to have a high alkalinity. In the water industry, alkalinity is expressed in mg/L of equivalent calcium carbonate. There are three kinds of alkalinity: carbonate, bicarbonate, and hydroxide alkalinity. Total alkalinity is the sum of all three kinds of alkalinity. Different tests are used to determine the quantity of the different kinds of alkalinities present in water. Automatic Controller: - ANSWER-A device that measures the value of a variable and operates to correct or limit de