Explanation:
total heat = Heat required to convert 2 kg of ice to 2 kg of water at 0 °C + Heat required to convert 2 kg of water at 0 °C to 2 kg of water at 20 °C.
Heat=mhfg+mCpΔT
Here, m ( mass of ice) = 2 kg
hfg (latent heat of fusion of ice) = 334 KJ
Cp of water (specific heat) = 4.187 KJ/Kg-K
ΔT(Temperature difference) = 20 °C
Therefore, Heat required = 2 x 334 + 2 x 4.187 x (20 - 0 )
Heat reqd= 835.48 KJ
Therefore, to melt 2 kg of ice 835.48 KJ of heat is required.
Answer: The enthalpy of combustion, per mole, of butane is -2657.4 kJ
Explanation:
The balanced chemical reaction is,
The expression for enthalpy change is,
![\Delta H=[n\times H_f_{products}]-[n\times H_f_{reactants}]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5Bn%5Ctimes%20H_f_%7Bproducts%7D%5D-%5Bn%5Ctimes%20H_f_%7Breactants%7D%5D)
Putting the values we get :
![\Delta H=[8\times H_f_{CO_2}+10\times H_f_{H_2O}]-[2\times H_f_{C_4H_{10}+13\times H_f_{O_2}}]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5B8%5Ctimes%20H_f_%7BCO_2%7D%2B10%5Ctimes%20H_f_%7BH_2O%7D%5D-%5B2%5Ctimes%20H_f_%7BC_4H_%7B10%7D%2B13%5Ctimes%20H_f_%7BO_2%7D%7D%5D)
![\Delta H=[(8\times -393.5)+(10\times -241.82)]-[(2\times -125.7)+(13\times 0)]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5B%288%5Ctimes%20-393.5%29%2B%2810%5Ctimes%20-241.82%29%5D-%5B%282%5Ctimes%20-125.7%29%2B%2813%5Ctimes%200%29%5D)
2 moles of butane releases heat = 5314.8 kJ
1 mole of butane release heat = 
Thus enthalpy of combustion per mole of butane is -2657.4 kJ
Explanation:
<u>Polar covalent bonding is the type of the chemical bond in which the pair of the electrons is unequally shared between the two atoms.</u> As a result, the atom with higher value of electronegativity acquires a slightly negative charge and the atom with lower value of electronegativity acquires a slightly positive charge.
In the molecule of 
, the bond which is closest to ionic end of bond spectrum is <u>N-H bond</u> because the nitrogen atom is more electronegative than hydrogen and is ionic in nature.
In the molecule of 
, the bond which is closest to ionic end of bond spectrum is <u>no one</u> because there is not much difference between carbon and hydrogen for the bond to be said as ionic.
In the molecule of 
, the bond which is closest to ionic end of bond spectrum is <u>O-H bond</u> because the oxygen atom is more electronegative than hydrogen and is ionic in nature.
1. Hydrogen has 1 electron.
The reaction occurs in a similar way as magnesium does, but much less vigorous. Strong heating is required to make iron powder burn in oxygen. The reaction gives out a yellow showery sparks and produces a black solid. iron reacts with dilute hydrocloric acid to give iron chloride and hydrogen gas.
