N=m/M
n=118/58.93=2
Answer: 2 moles
Answer:
Option D is good to go!
Explanation: as per the reactivity series more reactive substances will react with the counterpart substance.The most reactive substance here is calcium while the least reactive is aluminium, the magnesium comes in between.As per their reactivity, these substances will react with oxygen.
Explanation:
Answer: The correct answer is option (A).
Explanation:
Polar molecules are molecules in which formation of partial charges takes place due to which dipole moment gets created in a molecule. Molecules with polar bonds that s bond with partly ionic character. And water is of the example of polar molecule.
Electronegative oxygen atom in water molecule attracts the electron bond pair towards itself which generates partial negative charge on oxygen atom and partial positive charge on both hydrogen atoms.
Where as water has higher value surface tension due to strong intermolecular association of the water molecule due to presence of hydrogen bonding.And it is more denser is liquid state than in its solid state.
Hence,the correct answer is option (A).
I believe your answer is true! Hope this helps!
Answer:
412.1kJ
Explanation:
For the reaction , from the question -
4Fe (s) + 3O₂ (g) → 2Fe₂O₃ (s)
Δ Hrxn = Δ H°f (products) - Δ H°f (reactants)
In case the compound is in its standard state , enthalphy of formation is zero
Hence ,
for the above reaction ,
ΔHrxn =( 2 * Δ H° (Fe₂O₃ )) - [ ( 4 *Δ H° Fe ) + (3 * Δ H° O₂ )]
The value for Δ H°(Fe₂O₃ ) = - 824.2kJ/mol
Δ H° Fe = 0
Δ H° O₂ = 0
Putting in the above equation ,
ΔH rxn = ( 2 * Δ H° (Fe₂O₃ )) - 0
ΔHrxn = 2× - 824.2 kJ / mol = - 1648.4 kJ/mol
- 1648.4 kJ/mol , this much heat is released by the buring of 4 mol of Fe.
Hence ,
for 1 mol of Fe ,
- 1648.4 kJ/mol / 4 = 412.1kJ
