Flourine I guess must be the answer
Answer: Yes, the solute is a weak electrolyte
Explanation:
Depression in freezing point is given by:

= Depression in freezing point
i= vant hoff factor = ?
= freezing point constant = 
m= molality



As i for non electrolytes is 1, the given compound must be an electrolyte and a weak electrolyte as the value is only slightly greater than 1.
Here, Molar mass of N2O4 = 92.02 g/mol
So, Number of molecules in 1 mole (92.02 g) = 6.023 * 10²³
Number of molecules in 76.3 g = 6.023 * 10²³ / 92.02 * 76.3
= 6.023 * 10²³ / 1.20
= 5 * 10²³
In short, Your Answer would be approx. 5 * 10²³ molecules
Hope this helps!
D. Helps diagnose health problems
Answer:
The density is 0.0187 g/L
Explanation:
First thing to do here is to calculate the Volume of 1 mole of CO2 using the ideal gas equation
Mathematically;
PV = nRT
thus V = nRT/P
what we have are;
n = 1 mole
R is the molar has constant = 0.082 L•atm•mol^-1•K^-1
P is the pressure = 0.0079 atm
T is temperature = 227 K
Substituting these values, we have;
V = nRT/P = (1 * 0.082 * 227)/0.0079
V = 2,356.20 dm^3
This means according to the parameters given in the question, the volume of 1 mole of carbon iv oxide is 2,356.20 dm^3
But this is not what we want to calculate
What we want to calculate is the density
Mathematically, we can calculate the density using the formula below;
density = molar mass/molar volume
Kindly recall that the molar mass of carbon iv oxide is 44 g/mol
Thus the density = 44/2356.20 = 0.018674136321195 which is approximately 0.0187 g/L