The heat lost by the metal should be equal to the heat
gained by the water. We know that the heat capacity of water is simply 4.186 J
/ g °C. Therefore:
100 g * 4.186 J / g °C * (31°C – 25.1°C) = 28.2 g * Cp *
(95.2°C - 31°C)
<span>Cp = 1.36 J / g °C</span>
ANS: density = 13.41 g/ml
Density (d) of a substance is the mass (m) occupied by it in a given volume (v).
Density = mass/volume
i.e. d = m/v
m = (d) v -----(1)
The given equation from the plot of weight vs volume is :
y = 13.41 x ----(2)
Based on equations (1) and (2) we can deduce that the density of the metal is 13.41 g/ml
the oxidation states of the elements before and after the reaction is;
Pb oxidation state changes from 0 to +2
SO₄²⁻ ion there's no change in the oxidation state during the reaction
Au oxidation state changes from +3 to 0
reduction reactions are when there's a decrease in the oxidation state of the species
oxidation reactions are when theres an increase in the oxidation state of the species
the element where there's a decrease in oxidation state is Au.
Therefore Au gets reduced.
answer is B) Au
