Answer: The given statement is false.
Explanation:
Precipitation reaction is defined as the chemical reaction in which two aqueous solution upon mixing together results in the formation of an insoluble solid.
For example, 
Here AgCl is present in solid state so, it is the precipitate.
But it is not necessarily true that two aqueous solutions will always result in the formation of a precipitate.
For example, 
Hence, we can conclude that the statement precipitation reactions always occur when two aqueous solutions are mixed, is false.
Covalent bonding occurs when electrons are shared between atoms. Double and triple covalent bonds occur when four or six electrons are shared between two atoms, and they are indicated in Lewis structures by drawing two or three lines connecting one atom to another.
The correct answer is (C. zirconium - 93.
Answer:
pH = 12.2
Explanation:
Given data:
Mass of lime = 0.69 g
Volume = 1535 mL (1535 / 1000 = 1.535 L)
pH of solution = ?
Solution:
First of all we will determine the molarity.
Molarity = moles of solute / volume in litter
Number of moles = mass / molar mass
Number of moles = 0.69 g / 56.1 g/mol
Number of moles = 0.0123 mol
Molarity = moles of solute / volume in litter
Molarity = 0.0123 mol / 1.535 L
Molarity = 0.008 M
One mole of CaO neutralize two mole of OH⁻.
0.008 M×2 = 0.016 M
[OH⁻] = 0.016 M
pOH = -log [OH⁻]
pOH = [0.016]
pOH = 1.8
14 = pH +pOH
pH = 14 - pOH
pH = 14-1.8
pH = 12.2
