Answer:
a. [Na₂CrO₄] = 0.10 M
b. 0.017 moles of KBr
Explanation:
Molarity means a sort of concentration which indicates the moles of solute over 1L of solution.
We determine the moles of solute: 12.5 g / 162g/mol = 0.0771 moles
We convert the volume of solution from mL to L = 750 mL . 1L/1000mL = 0.750L
Molarity (mol/L) → 0.0771 mol / 0.750L = 0.10 M
b. In order to determine the moles of solute, with the molarity of solution and the volume we assume:
Molarity = moles of solute /volume of solution
Then, Molarity . Volume of solution (L) = moles of solute
We convert the volume of solution from mL to L = 150 mL . 1L/1000mL = 0.150L
0.112 mol/L . 0.150L = Moles of solute → 0.017 moles of KBr
Malia's table good conductors of electricity are aluminum, gold and platinum while bad conductors of electricity are silver, cork and plastic but her classification is wrong as silver is very good conductor of electricity So , the answer is option B that is Silver is a good conductor of electricity that is the reason that makes her classification wrong.