Answer:K2X
Explanation: Valency can be defined as the combining power of an element. It is the valency that dictates the value an element will have when writing a chemical formula for its compound.
MgX is a compound of magnesium and an element X. The valency of magnesium in most of its compound is +2. Now for the 2 to have been absent in the chemical formula, this shows that the element X itself have a valency if -2 for the valencies of both to have canceled out.
Now considering the element potassium, it is an alkaline metal belonging to group 1 of the periodic table. Hence, it is expected that it has a valency of +1
Forming a compound with element X means there would be an exchange of valencies between the two. We have established that x has a valency of -2. The formula of the compound thus formed by exchanging the valencies of both element would be K2X
The total pressure of the mixture of gases is equal to the sum of the pressure of each gas as if it is alone in the container. The partial pressure of a component of the mixture is said to be equal to the product of the total pressure and the mole fraction of the component in the mixture.
Partial pressure of hydrogen gas = 1.24 atm x .25 = 0.31 atm
Partial pressure of the remaining = 1.24 atm x (1-.25) = 0.93 atm