<span>Molds are created to achieve a
specific design of a material. These materials either came from a process of
having a higher or lower temperature. Therefore, the molder must have thermal
resistant properties. Low melting points means that the material to be shaped
came from a cooler process. Wood and metal have higher thermal conductivity and
therefore can easily be cooled. The wax can turn really hard and can be
unbreakable when present in colder materials due to the lipids present in it. Clay
however can become a mold because of its low melting point.</span>
Answer: <u>It is, as all stars are, a hot ball of gas made up mostly of Hydrogen. The Sun is so hot that most of the gas is actually plasma, the fourth state of matter. ... As we heat up liquid, the liquid turns to gas. Gas is the third state of matter</u>
Explanation:
i. The dissolution of PbSO₄ in water entails its ionizing into its constituent ions:

---
ii. Given the dissolution of some substance
,
the Ksp, or the solubility product constant, of the preceding equation takes the general form
.
The concentrations of pure solids (like substance A) and liquids are excluded from the equilibrium expression.
So, given our dissociation equation in question i., our Ksp expression would be written as:
.
---
iii. Presumably, what we're being asked for here is the <em>molar </em>solubility of PbSO4 (at the standard 25 °C, as Ksp is temperature dependent). We have all the information needed to calculate the molar solubility. Since the Ksp tells us the ratio of equilibrium concentrations of PbSO4 in solution, we can consider either [Pb2+] or [SO4^2-] as equivalent to our molar solubility (since the concentration of either ion is the extent to which solid PbSO4 will dissociate or dissolve in water).
We know that Ksp = [Pb2+][SO4^2-], and we are given the value of the Ksp of for PbSO4 as 1.3 × 10⁻⁸. Since the molar ratio between the two ions are the same, we can use an equivalent variable to represent both:

So, the molar solubility of PbSO4 is 1.1 × 10⁻⁴ mol/L. The answer is given to two significant figures since the Ksp is given to two significant figures.
Explanation:
It is known that the relation between heat energy, specific heat and change in temperature is as follows.
q =
where, q = heat released or absorbed
m = mass of substance
C = specific heat
= change in temperature
It is given that mass is 25.2 g and it is added to 150 ml container so total mass will be (25.2 g + 150 g) = 175.2 g,
is
,
is
, and specific heat of water is 4.184
.
Hence, putting the given values into the above formula as follows.
q =
=
= 
= -8430 J
As, 1 J = 0.001 kJ. Hence, -8430 J will also be equal to -8.43 kJ. The negative sign indicates that heat is being lost.
Thus, we can conclude that heat (kJ) was lost by the solution (surroundings) is 8.43 kJ.