Answer:
The reaction is spontaneous when T > 2170 K.
Explanation:
The spontaneity of a reaction is related to the standard Gibbs free energy (ΔG°). When ΔG° < 0 the reaction is spontaneous. ΔG° is related to the standard enthalpy (ΔH°) and the standard entropy (ΔS°) through the following expression:
ΔG° = ΔH° - T.ΔS°
where,
T is the absolute temperature
The reaction is spontaneous when ΔG° < 0, that is,
ΔH° - T.ΔS° < 0
ΔH° < T.ΔS°
T > ΔH°/ΔS° = (169.4 × 10³ J)/(78.1 J/K) = 2170 K
The reaction is spontaneous when T > 2170 K.
To solve this problem we will use the following equation:
w = (m of solute) / (m of solution)
w - percentage
It is necessary to mention here that mass of solution is a sum of the mass of solute and mass of water.
<span>w = mass CaCl2/(mass of water + mass of CaCl2)
</span>
mass of water = x
0.35 = 36 / (x + 36)
0.35 × (x + 36) = 36
0.35x + 12.6 = 36
0.35x = 23.4
x = 66.86 g of water is necessary
Answer:
The correct answer is B. Since the two metals have the same mass, but the specific heat capacity of iron is much greater than that of gold, the final temperature of the two metals will be closer to 498 K than to 298 K
Explanation:
Iron is hotter and gold is colder, therefore, according to laws of thermodynamics, iron will lose heat to gold until they are at the same temperature.
The specific heat capacity of iron(0.449) is over three times that of gold(0.128). Since masses are equal, this means that each time iron's temperature drops by one degree, the energy released it releases makes gold's temperature increase by more than 3 degrees. So gold's temperature will be climbing much faster than iron's is falling. Meaning they will meet closer to the initial temperature of iron than that of gold
Answer:
<h2>1. Ionic compound-
</h2><h2>2. Polar molecular compound-
</h2>
Explanation:
Mg is a metal that has 12 atomic numbers and thus its electronic configuration is 
. The outer most shell of this element has 2 electrons so it loses 2 electrons and thus form 
ions. Br is a nonmetal and has 35 atomic number so its electronic configuration is 
. Since its outermost shell has 7 electrons so it can accept one electron and thus forms 
. So magnesium ion and bromide ion combine and forms an ionic compound .
P is also a nonmetal and combine with Br with covalent bond and due to electronegativity differences form polar covalent compound such as .
It is scandium or titanium iron chroniclemium vanadium manganese
