Answer: Freezing point of a solution will be 
Explanation:
Depression in freezing point is given by:

= Depression in freezing point
i= vant hoff factor = 1 (for non electrolyte)
= freezing point constant = 
m= molality

Weight of solvent (benzene)= 1480 g =1.48 kg
Molar mass of solute (octane) = 114.0 g/mol
Mass of solute (octane) = 220 g



Thus the freezing point of a solution will be 
Answer:
Mass = 4.6 g
Explanation:
Given data:
Number of molecules of sucrose = 8.1 ×10²¹ molecules
Mass of sucrose = ?
Solution:
First of all we will calculate the number of moles by using Avogadro number.
1 mole × 8.1 ×10²¹ molecules / 6.022×10²³ molecules
1.35 × 10⁻² mol
Mass of sucrose:
Mass = number of moles × molar mass
Molar mass = 342.3 g/mol
Mass = 1.35 × 10⁻² mol ×342.3 g/mol
Mass = 462.1 × 10⁻² g
Mass = 4.6 g
Answer:
The mass of reactants and products are equal hence the reaction obeys law of conservation of mass
Explanation:
The law of mass conservation states that for a closed system to all transfer of mass, the mass of system must remain constant over time. This means for a chemical reaction, the mass of reactants must equal the mass of products.
if 2.796g of Zn reacts with 2.414g of sulphur to produce 4.169g of ZnS ad 1.041g of unreacted sulphur, then it means that accorfing to the law of mass conservation, the mass of reactants (zinc and sulphur), must be equal to mass of products (zinc sulfide and unreacted sulphur)
Mass of reactants = 2.796g + 2.414g =5.21g
Mass of products = 4.169g + 1.041g=5.21g