<h3><u>Answer;</u></h3>
<u>= 5 M or 5 moles/liter</u>
<h3><u>Explanation;</u></h3>
At point E, 90 g of substances X are dissolved in 100 g of the solvent.
100g of the solvent is equal to 100 ml
Molarity is the number of moles of a substance in one liter of a solvent.
90 g of X are in 100 ml
But; the RFM of X = 180 g/l
Therefore; the moles of X in 90 g = 90/180
= 0.5 moles
Therefore;
0.5 moles of X are contained in 100 ml of the solvent;
Thus, molarity = 0.5 × 1000/100
=<u> 5 M or 5 moles/liter</u>
Answer:
The substance is most likely NaCl.
Explanation:
Solubility:
As stated in statement the substance is insoluble in CCl₄ (Tetrachloromethane), it shows that the substance is polar in nature. In given options only C₁₀H₈ is soluble in CCl₄ because both are non polar in nature and like dissolves like. Hence, C₁₀H₈ is rejected.
Density:
Now, we are left with three options. NaCl, FeCl₃ and SiO₂. The student found that the density of substance is 2.20 g.mL⁻¹. Which is very close to the density of NaCl (i.e. 2.165 g.mL⁻¹). Therefore, most probably the substance the student is dealing with is Sodium Chloride.