Where are the substances?
Well I have no clue on what your class is doing but to me, it looks like B. the dependent variable also increases
False; Because when 2 substances are mixed another substance is created.
Answer: The thermal energy that would be released by 276.0g of sodium acetate trihydrate is 71.8kJ.
Explanation:
Supercooling is the process of lowering the temperature a liquid below its freezing point, without it becoming solid. A liquid below its freezing point will crystallize in the presence of a seed crystal because it serves as a structure for formation of crystals. From the question,
The given mass of sodium acetate trihydrate
(CH3COONa.3H2O)= 276.0g
Molar mass of sodium acetate
trihydrate= 136.08g/mol
Thermal heat of fusion of sodium acetate
trihydrate = 35.9 kJ/mol
From the given mass the number of moles present= 276.0/ 136.08
= 2.0moles
Therefore the heat (thermal) energy of the given mass of sodium acetate
trihydrate = 2.0 × 35.9
= 71.8kJ
Therefore, upon addition of a small seed crystal, the solution temperature increases as sodium acetate trihydrate crystallizes.
Answer:
(a) The unit cell edge length <u>0.421 nm</u>
Explanation:
Lets calculate -:
Given -
density = 
Molecular weight of MgO = 24.31 +16
Avagadro number = 
In rock salt structure , there are four anions and four cations , hence Z=4 (Number of formula per unit cell)
Now, using the formula -
![a=[\frac{ZM}{N_Ad}]]^\frac{1}{3}](https://tex.z-dn.net/?f=a%3D%5B%5Cfrac%7BZM%7D%7BN_Ad%7D%5D%5D%5E%5Cfrac%7B1%7D%7B3%7D)
Now, putting the given values
= 0.421 nm
<u>Hence , the unit cell edge length = 0.421 nm </u>
