Which coupling method is sensitive to temperature changes?

Direct coupling

Explanation:

Direct coupling is sensitive to changes that occurs in temperature. It is electrical energy transfer using physical contact through a medium that is conductive.

It is useful in the interconnection of 2 circuits. This kind of coupling method can be done by a wire, a resistor or through mettalic bonding.

The molarity is 0.203 M

Explanation:

Using the formula C(oxi) x V(oxi) / [C(red)  x  V(red)] = N(oxi) / N(red)

Where oxi and red means reducing agent and oxidising agent respectively.

C = Concentration, V = Volume and N = number of moles.

C(oxi) = 0.5 M

V(oxi) = mL

C(red) = ?

V(red) = 30mL

 Equation of reaction = 2K2S2O3 + KI3 = K2S4O6 + 3KI

so N(red) = 1 , N(oxi) = 2

from the equation above,

C(red) = 0.5 x 25 x 1 / (2 x 30)

          = 0.203 M.