Answer:
If you contact water with a gas at a certain temperature and (partial) pressure, the concentration of the gas in the water will reach an equilibrium ('saturation') according to Henry's law.
Explanation:
This means: if you increase the pressure (e.g. by keeping the vial closed), the CO2 concentration will increase. So it simply depends what concentration you need for your assay: 'CO2-saturated' water at low pressure or 'CO2-saturated' water at high pressure.
Answer:
Molar mass→ 0.930 g / 6.45×10⁻³ mol = 144.15 g/mol
Explanation:
Let's apply the formula for freezing point depression:
ΔT = Kf . m
ΔT = 74.2°C - 73.4°C → 0.8°C
Difference between the freezing T° of pure solvent and freezing T° of solution
Kf = Cryoscopic constant → 5.5°C/m
So, if we replace in the formula
ΔT = Kf . m → ΔT / Kf = m
0.8°C / 5.5 m/°C = m → 0.0516 mol/kg
These are the moles in 1 kg of solvent so let's find out the moles in our mass of solvent which is 0.125 kg
0.0516 mol/kg . 0.125 kg = 6.45×10⁻³ moles. Now we can determine the molar mass:
Molar mass (mol/kg) → 0.930 g / 6.45×10⁻³ mol = 144.15 g/mol
Answer:
<u>d. a row of elements</u>
Explanation:
Elements that are in the same group, have same number of electrons and make up a column in a periodic table.
Description:
<span>"0.0400 mol of H2O2 decomposed into 0.0400 mol of H2O and 0.0200 mol of O2."
This means that a certain amount of H2O2 (0.0400 mol) decomposed or was broken down into two components, 0.04 mol of H2O and 0.02 mol of O2. To examine the system, we need a balanced equation:
H2O2 ---> H2O + 0.5O2
The final concentrations of the system indicates that the system is in equilibrium. </span>
