Answer:
Explanation:
It is a physical change .
If we start from 10 atm of pressure and - 40 celsius of temperature to 20 atm of pressure and 70 celsius of temperature , it is a change in which pressure increases and temperature also increases that means heat is added up to the gas . If we cool the gas we can retrieve its earlier pressure and temperature .
So it is a physical change . In physical change , we can retrieve the old position by simple means.
Zinc oxide and zinc sulfide react with HCl: ZnS(s) + 2 HCl(aq) > ZnCl2(aq) + H2S(g)
Answer:
The solution is 4.93 molal
Explanation:
We assume that solution is aqueous.
We need to apply the colligative property of elevation of boiling point:
ΔT = Kb . m . i
ΔT = Boiling T° of solution - Boiling T° of pure solvent
110.1°C - 100°C = 10.1°C
Kb = 0.512 °C/m
m = molality → unknown
i = Van't Hoff factor (numbers of ions dissolved)
We assume 100 % dissociation: CoCl₃ → Co³⁺ + 3Cl⁻ i = 4
We have 1 mol of Co³⁺ + 3 moles of chlorides
We replace data → 10.1°C = 0.512°C/m . m . 4
10.1°C / (0.512 m/°C . 4) = m → 4.93
Add 3.3g of NaOH to 550 mL of water.
The ideal gas under STP is 22.4 L/mol. While the gas has a rule of P1V1/T1=P2V2/T2. So the volume under 101 kPa and 273 K is 0.2*22.4=4.48 L.