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.
The concentration of the HCl solution is 0.047 M.
Explanation:
Data given about acid and base:
volume of acid Vacid = 46.9 ml
molarity of acid =?
volume of the base (NaOH) = 16.4 ml
molarity of the base = 0.135 M
To know the concentration of the acid in this reaction, the formula used in titration is used. It is
Macid X Vacid = Mbase X Vbase
the formula is rewritten as:
Macid = 
putting the values in the equation:
Macid = 
= 0.047 M
the concentration of the acid i.e HCl in the solution is of 0.047 M.
Answer:
C. The conclusions tell why the data support or reject the hypothesis.
It will likely give up its valence electron to the other compound, forming stable octets on each of the newly formed ions. These ions have opposing charges, and tend to form strong ionic lattices. A good example of this is NaCl, which contains Na+ ions that have given up their one valence electron and Cl- ions which have accepted that electron.
Hope this helps!