Answer:
Ag⁺, Ba²⁺,
Explanation:
We can solve this question using the <em>solubility rules:</em>
<em>When an Halide as Br- is added to a solution, the ions that can be precipitate are Ag⁺, Hg₂²⁺ and Pb²⁺.</em>
That means the first ion present is Ag⁺
<em>When sulfates, SO₄²⁻ are added, the ions that precipitates are: Ag⁺, Ca²⁺, Sr²⁺, Ba²⁺, Hg₂²⁺ and Pb²⁺</em>
The second ion present is Ba²⁺
Hydroxides of Cu²⁺ and Mn²⁺ are insolubles but as no precipitate are formed when the solution is strongly alkaline those ions are not present.
I think that it’s A i have done a test on this before so I think it’s A
Answer:
Explanation:
Chemical properties of atoms relies solely on the number of electrons they contain, more particularly, the valence or outermost electrons in the orbit round the nucleus of an atom.
A neutral atom is one that has not gained or lost electron or even shared electrons with any other atom.
On close examination of how electrons are distributed in the orbits of an atom, we can know if an atom will gain or lose electrons in a reaction. This is very important in determining the chemical properties of an atom.
The empirical formula for this would be FeS
Answer : The value of 
is -24.9 kJ/mol
Explanation :
First we have to calculate the value of 'Q'.
The given balanced chemical reaction is,
The expression for reaction quotient will be :
In this expression, only gaseous or aqueous states are includes and pure liquid or solid states are omitted.
Now put all the given values in this expression, we get
Now we have to calculate the value of .
The formula used for is:
............(1)
where,
= Gibbs free energy for the reaction = ?
= standard Gibbs free energy = -28.0 kJ/mol
R = gas constant = 
T = temperature = 298 K
Q = reaction quotient = 3.375
Now put all the given values in the above formula 1, we get:
Therefore, the value of is -24.9 kJ/mol
