Chemical reaction: Ba(NO₃)₂ + H₂SO₄ → BaSO₄ + 2HNO₃.
V(H₂SO₄) = 250 mL ÷ 1000 mL/L = 0,25 L.
m(BaSO₄) = 0,55 g.
n(BaSO₄) = m(BaSO₄) ÷ M(BaSO₄).
n(BaSO₄) = 0,55 g ÷ 233,38 g/mol.
n(BaSO₄) = 0,00235 mol.
From chemical reaction: n(BaSO₄) : n(Ba(NO₃)₂) = 1 : 1.
n(Ba(NO₃)₂) = 0,00235 mol.
c(Ba(NO₃)₂) = n(Ba(NO₃)₂) ÷ V.
c(Ba(NO₃)₂) = 0,00235 mol ÷ 0,25 L.
c(Ba(NO₃)₂) = 0,0095 mol/L.
Answer:
The change in the internal energy of the system -878 J
Explanation:
Given;
energy lost by the system due to heat, Q = -1189 J (negative because energy was lost by the system)
Work done on the system, W = -311 J (negative because work was done on the system)
change in internal energy of the system, Δ U = ?
First law of thermodynamics states that the change in internal energy of a system (ΔU) equals the net heat transfer into the system (Q) minus the net work done by the system (W).
ΔU = Q - W
ΔU = -1189 - (-311)
ΔU = -1189 + 311
ΔU = -878 J
Therefore, the change in the internal energy of the system -878 J
Mary thinking her astrological sign, Leo, is a perfect fit for her personality is a belief in pseudoscience because there is not scientific evidence confirming such beliefs.
The answer is the second option.
Equation: MgOH2 (s) --> MgO (s) + H2O (g)
And it's already balanced.
I had chemistry this semester too.