The standard reduction potentials ( E^ ) for four metals P, Q, R, and S are given as follows: E^ _ P ²⁺/ P = -2.93 V E^ _ Q ²⁺/ Q = -0.74 V E^ _ R ²⁺/ R = +0.34 V E^ _ S ²⁺/ S = +0.80 V Which of the following metals can displace exactly two of the other metals from their respective aqueous salt solutions?

Step-by-step solution

A metal can displace another metal from its aqueous salt solution if it has a lower (more negative) standard reduction potential than the other metal. Arranging the metals in increasing order of their standard reduction potentials: P ( -2.93 V ) Evaluating the displacement capacity of each metal: - Metal P has the lowest E^ and can displace Q, R, and S (3 metals). - Metal Q can displace metals with higher E^ values than itself, which are R and S (exactly 2 metals). - Metal R can displace only S (1 metal). - Metal S