Arrange the following aqueous solutions in order of increasing boiling points. 0.050 m Mg(NO 3) 2; 0.100 m ethanol; 0.090 m NaCl
a. Mg(NO3) < NaCl < ethanol
b. ethanol < Mg(NO3)2 < NaCl
c. ethanol < NaCl < Mg(NO3)2
d. NaCl < ethanol < Mg(NO3)2
e. Mg(NO3)2 < ethanol < NaCl

The correct choice is option b. ethanol < Mg(NO3)2 < NaCl

Explanation:

Ethanol = 0.100 m

Mg(NO3)2 = 0.15 m

NaCl = 0.18 m

The molar concentration of NaCl is the highest, which is why its boiling point will be the highest, too.

1. 1 mole of anything contains 6.022x10^23 pieces  

d  

2. a  

3. c, number  

5. 1.24x10^24atoms / 6.022x10^23atoms/mole = 2moles h2 atoms  

6. fe2br3 mass = 2moles x mass fe + 3 moles x mass br  

molar mass = grams / number of moles = g/mole  

to find moles = g / molar mass  

to find mass = g = molar mass / moles