Q1)
molarity is defined as the number of moles of solute in 1 L of solution.
the NaCl solution volume is 1.00 L
number of moles NaCl = NaCl mass present / molar mass of NaCl
NaCl moles = 112 g / 58.5 g/mol = 1.91 mol
the number of moles of NaCl in 1.00 L of solution is - 1.91 mol
therefore molarity of NaCl is 1.91 M
Q2)
molality is defined as the number of moles of solute in 1 kg of solvent.
density is mass per volume.
density of the solution is 1.08 g/mL.
therefore mass of the solution is = density x volume
mass = 1.08 g/mL x 1000 mL = 1080 g
since we have to find the moles in 1 kg of solvent
mass of solvent = 1080 g - 112 g = 968 g
number of moles of NaCl in 968 g of solvent - 1.91 mol
therefore number of NaCl moles in 1000 g - (1.91 mol / 968 g) x 1000 g/kg = 1.97 mol/kg
molality of NaCl solution is 1.97 mol/kg
Q3)
mass percentage is the percentage of mass of solute by total mass of the solution
mass percentage of solution = mass of solute / total mass of the solution
mass of solute = 112 g
total mass of solution = 1080 g
mass % of NaCl = 112 g / 1080 g x 100%
therefore mass % of NaCl = 10.4 %
answer is 10.4 %
Answer:
I think the answer is B. the number of students choosing each color.
Explanation:
Answer:
heating makes the alcohol molecules of the liquid move faster.
Answer:
most endothermic reactions
Explanation:
In endothermic reactions, the entropy of the environment decreases.
The entropy is the measure of the disorder of a specific system.
An endothermic reaction is every chemical reaction in which energy is absorbed.
In a comparison of an endodermic reaction in which energy is released in light or heat form.
Answer:
Option C. +150KJ
Explanation:
Data obtained from the question include:
Heat of reactant (Hr) = 200KJ
Heat of product (Hp) = 350KJ
Change in enthalphy (ΔH) =..?
The enthalphy of the reaction can be obtained as follow:
Change in enthalphy (ΔH) = Heat of reactant (Hp) – Heat of reactant (Hr)
ΔH = Hp – Hr
ΔH = 350 – 200
ΔH = +150KJ
Therefore, the enthalphy for the reaction above is +150KJ
