Answer : The resonance structure of
is shown below.
Explanation :
Resonance structure : It is defined as when more than one Lewis structure can be drawn, the molecule or ion is said to have resonance.
Resonance is the concept where electrons (bonds) are delocalized over three or more atoms which cannot be depicted with one simple Lewis structure.
First we have to draw Lewis-dot structure.
Lewis-dot structure : It shows the bonding between the atoms of a molecule and it also shows the unpaired electrons present in the molecule.
In the Lewis-dot structure the valance electrons are shown by 'dot'.
The given molecule is, 
As we know that sulfur has '6' valence electrons, carbon has '6' valence electrons and nitrogen has '5' valence electron.
Therefore, the total number of valence electrons in
= 6 + 4 + 5 = 15
According to Lewis-dot structure, there are 7 number of bonding electrons and 8 number of non-bonding electrons.
In SCN, carbon atom is the central atom and sulfur and nitrogen are the neighboring atoms.
The resonance structure of
is shown below.
Answer: The enthalpy of the given reaction is 1234.8kJ/mol.
Explanation: Enthalpy change of the reaction is the amount of heat released or absorbed in a given chemical reaction.
Mathematically,

For the given reaction:





![\Delta H_{rxn}=\Delta H_f_{(C_2H_5OH)}+3\Delta H_f_{(O_2)}-[2\Delta H_f_{(CO_2)}+3\Delta H_f_{(H_2O)}]](https://tex.z-dn.net/?f=%5CDelta%20H_%7Brxn%7D%3D%5CDelta%20H_f_%7B%28C_2H_5OH%29%7D%2B3%5CDelta%20H_f_%7B%28O_2%29%7D-%5B2%5CDelta%20H_f_%7B%28CO_2%29%7D%2B3%5CDelta%20H_f_%7B%28H_2O%29%7D%5D)
Putting values in above equation, we get:
![\Delta H_{rxn}=[-277.6+3(0)]-[2(-393.5)+3(-241.8)]kJ/mol](https://tex.z-dn.net/?f=%5CDelta%20H_%7Brxn%7D%3D%5B-277.6%2B3%280%29%5D-%5B2%28-393.5%29%2B3%28-241.8%29%5DkJ%2Fmol)

there are 1023 atoms in pure aluminium
Answer:
Molarity = 0.08 M
Explanation:
Given data:
Mass of copper sulfate = 3.8 g
Volume of water = 250 cm³ (250/1000 = 0.25 L)
Concentration of solution = ?
Solution:
Number of moles of copper sulfate:
Number of moles = mass/molar mass
Number of moles = 3.8 g/ 159.6 g/mol
Number of moles = 0.02 mol
Concentration:
Molarity = Number of moles / volume in L
By putting values,
Molarity = 0.02 mol / 0.25 L
Molarity = 0.08 mol/L
Molarity = 0.08 M
Answer:
1.80 x 10^24 atoms
Explanation:
3moles × 6.022×10^23 atoms/mole