Answer:
Volume of HNO₃ required = 140 mL
Explanation:
Given data:
Molarity of HNO₃ = 0.563 M
mass of BaCO₃ = 7.83 g
Volume of HNO₃ = ?
Solution:
First of all we will write the balance chemical equation
2HNO₃ + BaCO₃ → Ba(NO₃)₂ + H₂O + CO₂
Number of moles of BaCO₃ = mass / molar mass
Number of moles of BaCO₃ = 7.83 g / 197.34 g/mol
Number of moles of BaCO₃ = 0.04 mol
Now we compare the moles of BaCO₃ and HNO₃ .
BaCO₃ : HNO₃
1 : 2
0.04 : 2×0.04 = 0.08 mol
Volume of HNO₃ required = number of moles / Molarity
Volume of HNO₃ required = 0.08 mol / 0.563 mol/L
Volume of HNO₃ required = 0.14 L
0.14 × 1000 = 140 mL
Answer:
a) ΔU = 370 KJ
b) Endothermic
Explanation:
a)
The change in energy of the mixture can be given by first law of thermodynamics as:
ΔQ = ΔU + W
ΔU = ΔQ - W
where,
ΔQ = change in heat energy of system
ΔU = Change in internal energy of gases
W = Work done on gases = - 155 KJ
For an isobaric process (i.e constant pressure) we know that:
ΔQ = change in enthalpy = ΔH
ΔQ = 215 KJ
Therefore, using values in the equation, we get:
ΔU = 215 KJ - (-155 KJ)
<u>ΔU = 370 KJ</u>
b)
Since, the enthalpy of products is greater than the reactants. Therefore, this is an <u>endothermic reaction</u>.