Answer : The specific heat (J/g-K) of this substance is, 0.780 J/g.K
Explanation :
Molar heat capacity : It is defined as the amount of heat absorbed by one mole of a substance to raise its temperature by one degree Celsius.
1 mole of substance releases heat = 92.1 J/K
As we are given, molar mass of unknown substance is, 118 g/mol that means, the mass of 1 mole of substance is, 118 g.
As, 118 g of substance releases heat = 92.1 J/K
So, 1 g of substance releases heat = 
Thus, the specific heat (J/g-K) of this substance is, 0.780 J/g.K
Answer:
1.04g of iron III carbonate
Explanation:
First, we must put down the equation of reaction because it must guide our work.
2Fe(NO3)3(aq) + 3Na2CO3(aq)→Fe2(CO3)3(s) + 6NaNO3(aq)
From the question, we can see that sodium carbonate is in excess while sodium nitrate is the limiting reactant.
Number of moles of iron III nitrate= mass of iron III nitrate reacted/ molar mass of iron III nitrate
Mass of iron III nitrate reacted= 1.72g
Molar mass of iron III nitrate= 241.88 g∙mol–1
Number of moles of iron III nitrate= 1.72g/241.88 g∙mol–1= 7.11×10^-3 moles
From the equation of the reaction;
2 moles of iron III nitrate yields 1 mole of iron III carbonate
7.11×10^-3 moles moles of iron III nitrate yields 7.11×10^-3 × 1/ 2= 3.56×10^-3 moles of iron III carbonate
Theoretical mass yield of iron III carbonate = number of moles of iron III carbonate × molar mass
Theoretical mass yield of iron III carbonate = 3.56×10^-3 moles ×291.73 g∙mol–1 = 1.04g of iron III carbonate
Answer:
a) The structure of anthracene is planar with all the pi electrons delocalized in the structure to maintain aromaticity.
b) The C-C bond length in anthracene is about 140 pm with all the bond lengths being similar to each other.
The standard C-C bond length is 154 pm while standard C=C bond is about 134 pm. Therefore the bond length in anthracene is smaller than standard C-C bond length and longer than standard C=C bond length. This can be explained from the fact that the C-C bonds in anthracene has be mixed characteristics of single and double bond because of the delocalization of pi electrons over the whole structure. As a result, they are neither fully single nor fully double bond in nature. Hence the observed bond lengths.
c) This molecule is not flat. The N-atom is sp3 hybridized here and the H-atom attached to N will remain out of plane.
Explanation:
Answer : The enthalpy change for the reaction is, 201.9 kJ
Explanation :
According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.
The balanced reaction of 
will be,
The intermediate balanced chemical reaction will be,
(1) 
(2) 
(3) 
(4) 
Now we will multiply the reaction 1 by 2, revere the reaction 2, reverse and half the reaction 3 and 4 then adding all the equations, we get :
(1) 
(2) 
(3) 
(4) 
The expression for enthalpy of the reaction will be,
Therefore, the enthalpy change for the reaction is, 201.9 kJ
