Answer:
34.9 g/mol is the molar mass for this solute
Explanation:
Formula for boiling point elevation: ΔT = Kb . m . i
ΔT = Temperatures 's difference between pure solvent and solution → 0.899°C
Kb = Ebullioscopic constant → 0.511°C/m
m = molality (moles of solute/1kg of solvent)
i = 2 → The solute is a strong electrolyte that ionizes into 2 ions
For example: AB ⇒ A⁺ + B⁻
Let's replace → 0.899°C = 0.511 °C/m . m . 2
0.899°C / 0.511 m/°C . 2 = m → 0.879 molal
This moles corresponds to 1 kg of solvent. Let's determine the molar mass
Molar mass (g/mol) → 30.76 g / 0.879 mol = 34.9 g/mol
Answer:
The answer should be 1000 kg / m3
Answer:
% purity of limestone = 96.53%
Explanation:
Question (4).
Weight of impure CaCO₃ = 25.9 g
Molecular weight of CaCO₃ = 40 + 12 + 3(16)
= 100 g per mole
We know at S.T.P. number of moles of CO₂ = 1 and volume = 22.4 liters
From the given reaction, 1 mole of CaCO₃ reacts with 1 mole or 22.4 liters of
CO₂.
∵ 22.4 liters of CO₂ was produced from CaCO3 = 100 g
∴ 1 liter of CO₂ will be produced by CaCO₃ = 
∴ 5.6 liters of CO₂ will be produced by CaCO₃ = 
= 25 g
Therefore, % purity of CaCO₃ = 
= 
= 96.53 %
Physical
When something is cooling it isn’t changing it’s chemical composition so it’s physical
I think it's 10 but i may not be right so, sorry if it's wrong lol