Answer:
(c) only Ca2+(aq) and Hg2+(aq)
Explanation:
- In the first step, hydrochloric acid (HCl) is added to the solution. In this case the equilibrium that could take place is:
Ag⁺(aq) + Cl⁻(aq) ↔ AgCl(s)
But no precipitate was formed, so Ag⁺(aq) is absent.
- By adding H₂SO₄(aq) the next equilibrium that could take place is:
Ca⁺²(aq) + SO₄⁻²(aq) ↔ CaSO₄(s)
A white precipitate was formed, so Ca⁺² is present in the solution.
- The following could take place after adding H₂S(aq):
Hg²⁺(aq) + S⁻² ↔ HgS(s)
A black precipitate formed, so Hg⁺² is present as well.
1a) anion and S-2
1b) cation and Al+3
1c) anion and N-3
1d) cation and Ca+2
Explanation:
Molar mass of
= 39.1 + 35.5 + 3(16.0) = 122.6 g
Molar mass of KCl = 39.1 + 35.5 = 74.6 g
Molar mass of
= 32.0 g
According to the equation, 2 moles of
reacts to give 3 moles of oxygen.
Therefore, 2 (122.6) = 245.2 g of
will give 3 (32.0) = 96.0 g of oxygen. Thus, 245.2 g of
gives 96.0 g of oxygen.
(a) Calculate the amount of oxygen given by 2.72 g of
as follows.
of
(b) Calculate the amount of oxygen given by 0.361 g of
as follows.
of
c) Calculate the amount of oxygen given by 83.6 kg
as follows.
of 
Convert kg into grams as follows.
= 32731 g of 
(d) Calculate the amount of oxygen given by 22.5 mg of
as follows.

Convert mg into grams as follows.
of 
Answer:
Explanation: The chemical reaction is written by writing down the chemical formulas of the reactants on the left hand side and the chemical formulas of products on the right hand side separated by a right arrow.
This is a single displacement reaction in which a more reactive element displaces the less reactive element from its salt solution. Thus sodium is more reactive than Mg and thus displaces it from
.

The number of atoms of each element must be same on both sides of the reaction so as to follow the law of conservation of mass.
Thus the equation is balanced.