The percentage of water in an unknown hydrated salt is to bedetermined by weighing a sample of the salt, heating it to driveoff water, cooling it to room temperature, and re-weighing. whichprocedural mistake would result in determining a percentage ofwater that is too low?
procedural mistakes

i. heating the sample in aclosed, rather than an open, container
ii. re-weighing thesample before it has cooled to room temperature

a. i only
b. ii only
c. both i andii
d. neither i norii

B

Explanation:

If the sample is reweighed after it is removed from the furnace without being cooled to room temperature, its percentage water content will be too low as there would be almost no water if crystalization at such high temperature. However, when it is cooled to room temperature, the actual percentage of water contained in the sample can be accurately determined by weighing.

the correct answer is b. a strong acid completely dissociates to its ions when dissolved in water. completely dissociates to and ions. a is incorrect because does not fully ionize to and ions and some remain as the compound . c and d are incorrect because, and do not fall into the category of bronsted lowry acids. a bronsted lowry acid is a proton donor and since both molecules do not have a proton to donate they are not bronsted lowry acids. likewise,   if we use the lewis acid definition, they cannot be acids. a lewis acid is an electron pair acceptor. both and have a complete octet so can not accept any electrons which disqualifies them as acids.