Answer:
a) and d) are false.
Explanation:
a) The second law of thermodynamics states that t<u>he entropy of the universe increases in a spon
taneous process and remains unchanged in an equilibrium process.</u>
For a spontaneous process:
ΔSuniv = ΔSsys + ΔSsurr > 0
For a spontaneous process, the second law says that ΔSuniv must be greater than zero, but it does not place a restriction on either ΔSsys or ΔSsurr. Thus, it is possible for either ΔSsys or ΔSsurr to be negative, as long as the sum of these two quantities is greater than zero.
d) <u>A reaction that does occur under the given set of conditions is called a</u> spontaneous reaction. We observe spontaneous physical and chemical processes every day, including many of the following examples:
• A waterfall runs downhill, but never up, spontaneously.
• A lump of sugar spontaneously dissolves in a cup of coffee, but dissolved sugar does not spontaneously reappear in its original form.
• Heat flows from a hotter object to a colder one, but the reverse never happens spontaneously.
Una sustancia homogénea es una sustancia que se compone de una sola fase. Recordemos que definimos una fase en química como "cantidad química y físicamente uniforme u homogénea de materia que se puede separar mecánicamente de una mezcla no homogénea y que puede consistir en una sola sustancia o una mezcla de sustancias" según Ecyclopedia Britiannica.
El hecho de que un sistema esté compuesto por una sola sustancia no lo hace es autóctono. A veces, un sistema puede estar compuesto por partículas sólidas de una sustancia en equilibrio con su líquido. El sistema contiene solo una sustancia pero en diferentes fases, por lo tanto, el sistema contiene una sustancia pero no es homogéneo.
Por tanto, el hecho de que un sistema contenga una sola sustancia no significa necesariamente que sea homogéneo.
Answer:
C) Precipitation
Explanation:
Above reaction forms the precipitate of (Magnesium Hydroxide). Hence, it is Precipitation reaction. This reaction is also known as Double displacement reaction.
Salt water spray blowing on it each day. This can quickly lead to rust because of all the salt.