1:2:6? Ba(NO3)2 +Na2SO4 -----> BaSO4 + 2NaNO3
Ba(NO3)2
BaSO4
NaNO 3
Na2SO4
The final temperature, t₂ = 30.9 °C
<h3>Further explanation</h3>
Given
24.0 kJ of heat = 24,000 J
Mass of calorimeter = 1.3 kg = 1300 g
Cs = 3.41 J/g°C
t₁= 25.5 °C
Required
The final temperature, t₂
Solution
Q = m.Cs.Δt
Q out (combustion of compound) = Q in (calorimeter)
24,000 = 1300 x 3.41 x (t₂-25.5)
t₂ = 30.9 °C
Mass of copper : 0.165 g
<h3>Further explanation</h3>
Given
5.0 A over 100 seconds
Required
Mass of copper
Solution
Faraday's law:
<em>The mass of the substance formed at each electrode is proportional to the electric current flowing in the electrolysis</em>
<em />
<em />
e = Ar / valence = eqivalent weight
i = current
t = time
W = weight
CuSO₄ ----> Cu²⁺ + SO₄²⁻
Cu ----> Cu²⁺ + 2e
e = Ar/2
= 63,5/2 = 31,75

<span>By definition:
pH = pKa + log [acetate]/ [acetic acid]
so
5.02 = 4.74 + log [acetate] / 10 mmole
10mmole = 10/1000 = 0.01 mole
5.02 = 4.74 + log [acetate] / 0.01
5.02 - 4.74 = 0.28 = log [acetate] /0.01
10^0.28 = </span><span>1.90546</span> = [acetate] / 0.01 <span>
[acetate] = 0.019 mole
= 19 millimoles
</span>