Chemistry Reveal Questions Chemistry Lab - Div C (Section: 3 / Line: 3) 10/25/2023 Are equilibrium pressures testable within the context of equilibrium calculations since it says equilibrium concentrations? Equilibrium partial pressure questions may be included at the State and National level competitions but NOT at the Invitational and Regional level competitions. Detector Building - Div C (Section: 3 / Line: 5) 10/24/2023 External ADCs, such as the ADS1115, come on PCBs with other resistors and capacitors, but no other ICs. Are these allowed? No, they are not allowed. They violate 3.c. (Section: 3 / Paragraph: a / Line: 2) 11/02/2023 It says in the rules that the ORP probe must be participant built; can teams purchase electrodes online as components of a probe and then use those to construct the probe itself? No, preassembled electrodes or electrodes from a probe are not allowed. The electrode must be student constructed (Section: 3 / Paragraph: g / Line: 1) 11/09/2023 Regarding the digital display of the salt concentration, may the display be more precise than the nearest unit value (e.g., 0.1 ppm, 0.01 ppm, etc.)? Perhaps the rule should be TO AT LEAST the nearest unit value. Yes, since 5.e. specifies that the Event Supervisor records the concentration in ppm to the nearest 1 ppm, there is no need for more precision. (Section: 2 / Paragraph: a / Line: 1) 10/05/2023 The language describing the device has been updated since Detector Building last ran Salt Concentration Sensing, changing from conductivity sensor to ORP probe. Is it required that the device be an ORP probe, or can it still use any means (within ... Yes, the device must be an ORP probe. Measuring conductivity via resistance or inductance with a conductivity probe is prohibited. (Section: 3 / Paragraph: b / Line: 1) 10/16/2023 The wording here has me a bit confused, are we allowed to purchase a salt bridge and electrode in order to combine them into an ORP sensor? Or do we have also have to construct a salt bridge and electrode from basic materials? Both the electrode and salt bridge are student constructed and can not be purchased as preassembled devices. (Section: 3 / Paragraph: b / Line: 1) 10/06/2023 Will a salt bridge containing metal be considered a salt bridge? No, it will not. (Section: 3 / Paragraph: b / Line: 1) 11/28/2023 Would a thermistor be considered a fundamental component and could we measure temperature to supplement our ORP readings as they could change with temperature? Yes, a thermistor would be considered a fundamental component. Forensics - Div C ‹ Physical Science & Chemistry Chemistry Lab - Div C ›
