Answer : The enthalpy change for the reaction is, 419.5 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.
The given chemical reaction is,
Now we have to determine the enthalpy change for the reaction below:
By reversing and then dividing the reaction by 2, we get the enthalpy change for the reaction.
The expression will be:
Therefore, the enthalpy change for the reaction is, 419.5 kJ
Here's my best guess
the volume of the unit cell is (385*10^-12)^3=5.7066*10^-29 m^3
multiply by density to get mass
mass = (7 g/cm^3)*(100^3 cm^3 / 1^3 m^3) * 5.7066*10^-29 m^3= 3.99466*10^-22 g
covert to moles
3.99466*10^-22 g * 1 mol / 239.82 g = 1.6657 *10^-24 mol
convert to number of units
1.6657 *10^-24 mol * 6.23*10^23 units/mol = 1.04
385 pm = 3.85*10^(-8) cm
The volume of the unit cell is the cube of that, which is 5.71*10^(-23) cm^3. Since the ratio of mass to volume (i.e. the density) must be the same no matter what amount of TlCl you have, you can say:
7 = x/(5.71*10^(-23)), where x is the mass of the unit cell. Solving for x, you get 4*10^(-22) g.
The mass of a molecule of TlCl is 240 amu, which in grams is 4*10^(-22) g. The mass of the unit cell and the mass of a molecule of TlCl is the same. Therefore there is one formula unit of TlCl per unit cell.
Answer:
1-b
2-weaker(option is incorrect)
3-a
Explanation:
1-b because iodine is more electronegative because of this negative on iodine will be more stable as negative charge on more electronegative element is more stable.
2-weaker as size of Te (Tellurium) is greater than S (sulphur) so bond length of H-Te is larger than H-S and therefore bond energy will be lesser and can easily give hydrogen in case of H-Te. as bond energy is inversly proportional to bond length.
3-a hydrogen has more negative electron affinity so hydrogen will have -1 charge and it will behave as a electron donar atom that is basic not acidic hence NaH is not acidic.
False, although the air is moving in an equilibrium us normal humans can not see the air actually moving. So it is false.
Dalton hypothesized that atoms are indivisible and that all atoms of an element are identical. It is now known that <span>atoms are divisible. The answer is letter C</span>
