.0002345 I believe this is correct
Answer:
A
Explanation:
The solubility of a substance is directly proportional to the temperature. It means that solubility will increase with the increases in temperature. At higher temperature, the kinetic energy increased that allow the solvent molecules to break the solute particles more effectively.
Substance A has a higher solubility because the weight of substance A measured at the end of the experiment is less than the weight of substance B.
Hence, the correct answer is A.
Answer:
C. 0.20 M Mg ion & 0.40 M Cl ion
Explanation:
MgCl₂ is a ionic salt which is dissociated as this
MgCl₂ → Mg²⁺ + 2Cl⁻
First of all, we have a solution of 200 mL, with [MgCl₂] = 0.6M
Molarity . volume = moles.
0.6 mol/l . 0.2l = 0.12 mol
MgCl₂ → Mg²⁺ + 2Cl⁻
0.12mol 0.12 0.24
This moles are also in 400mL of water, so the new concentration is
[Mg²⁺] = 0.12 m/0.6L = 0.2M
[Cl⁻] = 0.24 m/0.6L = 0.4M
Remember we initially have 200mL and then, we add 400 mL, so we supose aditive volume. (600mL)
Explanation:
A point of temperature at which both solid and liquid state of a substance remains in equilibrium without any change in temperature then this temperature is known as melting point.
For example, melting point of water is 
. So, at this temperature solid state of water and liquid state are present in equilibrium with each other.
Therefore, when a 100 g of given pure metal in solid state is heated at its exact melting point which is 
then some of the solid will change into liquid state but the temperature will remains the same.
Answer:
Molality = 7.5 mol/kg
Explanation:
Given data:
Mass of NH₄Cl = 6.30 g
Mass of water = 15.7 g (15.7/1000 =0.016 kg)
Molality = ?
Solution:
Formula of molality:
Molality = Moles of solute / mass of solvent in gram
Now we will first calculate the number of moles of solute( NH₄Cl )
Number of moles = mass/ molar mass
Molar mass of NH₄Cl = 53.491 g/mol
Number of moles = 6.30 g/ 53.491 g/mol
Number of moles = 0.12 mol
Now we will calculate the molality.
Molality = Moles of solute / mass of solvent in gram
Molality = 0.12 mol / 0.016 kg
Molality = 7.5 m
or (m=mol/kg)
Molality = 7.5 mol/kg
