Freezing point depression is a colligative property.
The formula that rules it is:
ΔT f = Kf * m
Where m is the molality of the solution => m = moles of solute / Kg of solvent
=> m = 0.31 mol / 0.175 kg = 1.771 m
And kf = 1.86 °C/m
=> ΔTf = 1.771 m * 1.86 °C / m = 3.3 °C
=> Freezing point of the solution = normal freezing point of water - 3.3 °C = 0 - 3.3°C = - 3.3°C.
Answer: -3.3 °C
1) k2O = 2K(1+) + O(2-)
This is, every molecule of K2O consists of three ions (2 of K 1+, and one of O 2-)
2) Caluclate the number of moles of K2O
- molar mass of K2O = 2*39 + 16 = 94 g/mol
- n = mass / molar-mass = 9.4g / 94 g/mol = 0.1 mol
3) Multiply by 3 to have the number of moles of ions: 3 *0.1 mol = 0.3 mol of ions.
4) Multiply by Avogadro's number to obtain the number of ions"
0.3 mol * 6.0*10^23 =1.8 * 10^23 ions.
Answer: 1.8*10^23 ions
Answer: Law of conservation of mass explains these observations.
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products formed must be equal to the mass of reactants taken.
In order to get the same mass on both sides, the atoms of each element must be balanced on both sides of the chemical equation.
Mass of reactants= mass of Mg+ mass of 
= 48 g + 32 g = 80 g
Mass of products = mass of 
= 80 g
Thus mass of reactants is equal to mass of products, thus law of conservation of mass is obeyed.
