Answer:
It is not a gas because its particles do not have large space between them.
Answer : The molecular weight of a substance is 157.3 g/mol
Explanation :
As we are given that 7 % by weight that means 7 grams of solute present in 100 grams of solution.
Mass of solute = 7 g
Mass of solution = 100 g
Mass of solvent = 100 - 7 = 93 g
Formula used :

where,
= change in freezing point
= temperature of pure water = 
= temperature of solution = 
= freezing point constant of water = 
m = molality
Now put all the given values in this formula, we get


Therefore, the molecular weight of a substance is 157.3 g/mol
The questions tha science can answer are those can be tested to try to find a definite answer.
For example, whether light is wave or particle is matter of science.
Questions that cannot have a definite answer are the field of religion or philosophy, and are out of the boundaries of science.
For example, does a criminal deserve the punishment of not seeing light? It is a moral question, which to be responded needs the intervention of philosophy and that could have different anwers at different times and in different societies.
Molar mass :
Li₂S = <span>45.947 g/mol
AlCl</span>₃ = <span>133.34 g/mol
</span><span>3 Li</span>₂<span>S + 2 AlCl</span>₃<span> = 6 LiCl + Al</span>₂S₃
3 * 45.947 g Li₂S ----------> 2 * <span>133.34 g AlCl</span>₃
1.084 g Li₂S ----------------> ?
Mass Li₂S = 1.084 * 2 * 133.34 / 3 * 45.947
Mass Li₂S = 289.08112 / 137.841
Mass Li₂S = 2.0972 g
hope this helps!