Answer:
Marcie pick up a rock
Explanation:
A rock is a natural occuring no living thing that has a definite structure from the physical characteristics Marcie saw in the rock she picked it tends to rock because unlike minerals rocks has definite structure.
<u>Answer:</u> The above reaction is non-spontaneous.
<u>Explanation:</u>
For the given chemical reaction:

Here, nickel is getting reduced because it is gaining electrons and iron is getting oxidized because it is loosing electrons.
We know that:

Substance getting oxidized always act as anode and the one getting reduced always act as cathode.
To calculate the
of the reaction, we use the equation:


Relationship between standard Gibbs free energy and standard electrode potential follows:

As, the standard electrode potential of the cell is coming out to be negative for the above cell. Thus, the standard Gibbs free energy change of the reaction will become positive making the reaction non-spontaneous.
Hence, the above reaction is non-spontaneous.
Answer : The mole fraction of nitrogen will be 0.4615.
Explanation : When nitrogen (
)and hydrogen (
)are mixed, the mole ratio becomes 1 : 1.5,
Now we know that (
) is acting as a limiting agent.
So at the time of when 0.4 moles of (
) is been formed it requires 0.4 moles of (
) and 3.4 moles of (
)
So, we find the the remaining (
) will be 0.6 and
(
) will be 0.3 mole present in mixture.
So, the mole fraction of (
) becomes = 0.6 / (0.6 + 0.4 + 0.3) Which becomes = 0.4615
Given mass of KNO₃=346g
Molar mass of KNO₃=(39.098)+(14)+(15.99*3)=101.068gmol⁻¹
Volume of Solution=750ml=0.75dm³
Molarity=(mass of solute/molar mass of solute)*(1/volume of sol. in dm³)
=(346/101.068)*(1/0.75)
=4.56 mol dm⁻³