The volume of Helium gas needed for storage is 2.00 L (answer C)
<u><em> calculation</em></u>
The volume of Helium is calculated using ideal gas equation
That is Pv =nRT
where;
P( pressure) = 203 KPa
V(volume)=?
n(number of moles) = 0.122 moles
R(gas constant) = 8.314 L.Kpa/mol.K
T(temperature)= 401 K
make V the subject of the formula by diving both side by P
V=nRT/p
V={[0.122 moles x 8.314 L. KPa/mol.K x 401 K] / 203 KPa} = 2.00 L
The initial mass of sodium hydroxide is 3.3 g (answer C)
<u><em>calculation</em></u>
Step 1 : find the moles of iron (ii) hydroxide ( Fe(OH)₂
moles = mass÷ molar mass
from periodic table the molar mass of Fe(OH)₂ = 56 + [16 +1]2 = 90 g/mol
moles is therefore = 3.70 g÷ 90 g/mol = 0.041 moles
Step 2: use the mole ratio to calculate the moles of sodium hydroxide (NaOH)
from given equation NaOH : Fe(OH)₂ is 2 :1
therefore the moles of NaOH = 0.041 x 2 = 0.082 moles
Step 3: find mass of NaOH
mass = moles x molar mass
from the periodic table the molar mass of NaOH = 23 +16 +1 = 40 g/mol
mass = 0.082 moles x 40 g/mol = 3.3 g ( answer C)
Answer:
Yes
Explanation:
A supercritical fluid has good properties for both liquid and as for extraction properties, the advantages then include:
- The fact that it has a lower viscosity than liquid CO2 allowing it to move through and around coffee beans more thoroughly with creating back pressure
- Its density is comparable to that of liquid CO2 meaning there is much CO2 per litre as there is liquid form making it more efficient
- It has a higher diffusivity than liquid CO2 which aids with penetration of the coffee beans on a molecular level
This experiment would not work with tea leaves because they also contain caffeine
Answer:
43.7
Explanation:
mole is equal mass concentration/ moler mass of MgCl²
<span>differences in the physical properties of the mixture's components</span>
