Magnesium, strontium and barium are a few of the elements that have the same properties as calcium. elements found in group 2 of the periodic table have similar properties to it.
Answer:
By using any one technique like boiling, distillation, condensation ,etc , one can be used to distinguish between a pure substance and a homogeneous mixture.
Explanation:
If the liquid is a pure substance, then it can not be separated by using physical means because all atoms of a pure substance show same properties.
But on the other hand, if there is homogeneous mixture, it can be separated by using techniques like boiling, distillation, condensation ,etc.
<u>Thus, using any of the one method listed above can be used to distinguish between a pure substance and a homogeneous mixture.</u>
Molar volume at STP = 22,4 L
1 mole -------------- 22,4 L
x mole -------------- 11,2 L
x = 11,2 / 22,4
x = 0,5 moles of N2
1 mole --------------- 6,02.10²³ molecules
0,5 moles ------------ y molecules
y = 0,5 . 6,02.10²³
y = 3,01.10²³ molecules
Answer:
1. False
2. False
3. True
4. False
Explanation:
1. CBr4 is more volatile than CCl4 False
The molecular weight of CBr4 is is greater than the CCl4, therefore it has less tendency to escape to the gas phase. Also, the CBr4 has greater London dispersion forces compared to CCl4 since bromine is a larger atom than chlorine.
2. CBr4 has a higher vapor pressure at the same temperature than CCl4 False
For the same reasons as above, the vapor pressure of CBr4 is smaller than the vapor pressure of CCl4
3. CBr4 has a higher boling point than CCl4 True
Again, CBr4 having a molecular weight greater than CCl4 ( 331 g/mol vs 158.2 g/mol) is heavier and less volatile with a higher boiling point than CCl4.
4. CBr4 has weaker intermolecular forces than CCl4 False
Both molecules are non-polar because the dipole moments in C-Cl and C-Br bonds cancel in the tetrahedron. The only possible molecular forces are of the London dispersion type which are temporary and greater for larger atoms.
An elements like helium and Boron are formed by stars having a mass of one to eight suns. The example elements that are formed by stars having a mass of one to eight suns are helium and boron. The stars normally turns into a white dwarf when the mass of the stars are less than 5 times the mass of the sun.
