Answer : If we list the given chemicals according to their increasing oxidising ability then the order will be like this; 1 being the strongest and 6 being the weakest
1. K > 2. Ca >3. Ni> 4. Cu> 5. Ag> 6.Au
Explanation : Considering the reduction potential of each chemical species it will be easy to identify their oxidising capacity and differentiate accordingly;
More negative the value of reduction potential more is the ability of the chemical species to get oxidised.
Chemicals with their reduction potential is given below.
K has -2.92; Ca has -2.76; Ni has -0.23; Cu has 0.52; Ag has 1.50 and Au has 1.50.
a) Copper is at a higher temperature, so the flow of heat will take place from copper to iron. Heat is a form of energy, which always flows from higher temperature to lower temperature.
b) To determine the actual final temperature, the heat capacity of the calorimeter must be known. A calorimeter constant refers to a constant, which quantifies the heat capacity of a calorimeter. It may be determined by using a known amount of heat to the calorimeter and measuring the corresponding change in temperature of the calorimeter.
I would answer B!! But your guess is as good as mine!!
