Answer:
333.7g of antifreeze
Explanation:
Freezing point depression in a solvent (In this case, water) occurs by the addition of a solute. The law is:
ΔT = Kf × m × i
Where:
ΔT is change in temperature (0°C - -20°C = 20°C)
Kf is freezing point depression constant (1.86°C / m)
m is molality of solution (moles solute / 0.5 kg solvent -500g water-)
i is Van't Hoff factor (1, assuming antifreeze is ethylene glycol -C₂H₄(OH)₂)
Replacing:
20°C = 1.86°C / m × moles solute / 0.5 kg solvent × 1
5.376 = moles solute
As molar mass of ethylene glycol is 62.07g/mol:
5.376 moles × (62.07g / 1mol) = <em>333.7g of antifreeze</em>.
the formula of the heavy water is D2O
There are 5 layers. The Lithosphere, the Asthenosphere, the outer core, the inner core and the mantel.
Answer : The value of 'R' is 
Solution : Given,
At STP conditions,
Pressure = 1 atm
Temperature = 273 K
Number of moles = 1 mole
Volume = 22.4 L
Formula used : 
where,
R = Gas constant
P = pressure of gas
T = temperature of gas
V = volume of gas
n = number of moles of gas
Now put all the given values in this formula, we get the values of 'R'.


Therefore, the value of 'R' is
.
They are called isotopes.