Answer:
d. ΔH° > 0, process is endothermic.
Explanation:
Cold packs contain ammonium nitrate (NH₄NO₃). When this salt dissolves in water, it decreases the temperature of the surroundings. This happens because the process is endothermic (absorbs heat from the surroundings). By convention, when a process is endothermic, the standard enthalpy carries a positive sign (ΔH° > 0).
Answer
oh my.. ima put that down in my conspiracy theory book
Explanation:
Answer:
Option 1 and 3 are correct.
Explanation:
Buffer solution is the solution which resists the change in the magnitude of the pH when small additions of either acid or base is added. Buffer solutions consist of weak acid and its conjugate base usually which are mixed in relatively equal and large quantities.
Hence,
Option 1. is correct because acetic acid is a weak acid and sodium acetate is the conjugate base of it which are mixed in equal concentrations.
Option 2. is incorrect because HCl and NaCl are both strong acid and salt respectively and will not form a buffer.
Option 3. is correct which is the definition of a buffer solution.
Option 1 and 3 are correct.
Answer:
if you are working with hazardous materials.
Explanation:
A properly operating and correctly used fume hood can reduce or eliminate exposure to volatile liquids, dusts, and mists. It is advisable to use a laboratory hood when working with all hazardous substances.