Answer:
= -356KJ
<em>therefore, the reaction where heat is released is exothermic reaction since theΔH is negative</em>
Explanation:
given that enthalpy of gaseous reactants decreases by 162KJ and workdone is -194KJ
then,
change in enthalpy (ΔH) = -162( released energy)
work(w) = -194KJ
change in enthalpy is said to be negative if the heat is evolved during the reaction while heat change(ΔH) is said to be positive if the heat required for the reaction occurs.
At constant pressure the change in enthalpy is given as
ΔH = ΔU + PΔV
ΔU = change in energy
ΔV = change in volume
P = pressure
w = -pΔV
therefore,
ΔH = ΔU -W
to evaluate energy change we have,
ΔU =ΔH + W
ΔU = -162+ (-194KJ)
= -356KJ
<em>therefore, the reaction where heat is released is exothermic reaction since theΔH is negative</em>
Convert grams to moles [grams/molar mass] ~ Moles
Convert moles to atoms [moles * 6.02 x 10^23] = Atoms
Half of 6.02 x 10^23 is 3.01 x 10^23 so here is our answer.
Answer:
The correct option is: C ) 14.4 lb
Explanation:
The standard International unit of mass is kilogram, kg. Other commonly used units of mass are grams (g), tonne (t), pounds (lb).
The mass of 500 mL liquid mercury is 6.53 kg.
Since, 1 kg = 2.20462 lb ≈ 2.205 lb
Therefore, the mass of 500 mL liquid mercury in pounds = 6.53 × 2.20462 = 14.39619 lb ≈ 14.4 lb.
Answer:- 
Solution:- First of all we calculate the heat absorbed or released when the solute is added to the solvent. Here the solute is LiCl and the solvent is water.
To calculate the heat absorbed or released we use the formula:

q = heat absorbed or released
m = mass of solution
s = specific heat capacity
and
= change in temperature
mass of solution = mass of solute + mass of solvent
mass of solution = 5.00 g + 100.0 g = 105.0 g
(note:- density of pure water is 1 g per mL so the mass is same as its volume)
= 33.0 - 23.0 = 10.0 degree C
s = 
Let's plug in the values in the formula and calculate q.
q = 
q = 4389 J
To calculate the enthalpy of solution that is
we convert q to kJ and divide by the moles of solute.
moles of solute = 
= 0.118 moles
q =
= 4.389 kJ

= 
Since the heat is released which is also clear from the rise in temperature of the solution, the sign of enthapy of solution will be negative.
So, 