Answer:
5) oxygen
7)0.5480 M
9)5s
10) 2 σ and 2 π bonds
12) All of the carbon-oxygen bonds in a carbonate ion are weaker than the carbon-oxygen bonds in a carbon dioxide molecule
19) 0.400 g
Explanation:
For question 5
C2H6 + 7/2 O2 -----> 2CO2 + 3H2O
If 1 mole of ethane gives 2 moles of carbon dioxide
13 moles of ethane will give 13×2 = 26 moles of carbon dioxide
If 3.5 moles of oxygen gives 2 moles of carbon dioxide
42 moles of oxygen will give 42×2/3.5 = 24 moles of carbon dioxide
The reactant that gives the lower number of moles of product is the limiting reactant. This means that oxygen is the limiting reactant here.
7) concentration of acid CA =2.456 M
Concentration of base CB= ???
Volume of acid VA= 15.41 ml
Volume of base VB= 34.53 ml
Number of moles of acid NA= 2
Number of moles of base NB= 1
Ca(OH)2(aq) + 2HCl(aq) ----> CaCl2(aq) + 2H2O (l)
CB= CA VA NB/VB NA
CB= 2.456 × 15.41 ×1/34.53×2
CB= 0.548 M
9) For question 9, we have to look at the electronic configuration of Rb. We have [Kr]5s1. The outermost 5s1 level will have the least effective nuclear charge and is easily lost.
10) There are two sigma bonds and two pi bonds in CO2
12) The C-O bond length in the carbonate ion is 136 pm while the C-O bond length in CO2 is 116 pm. The longer the bond, the weaker the bond hence the C-O bonds in the carbonate ion are weaker than those in the carbon dioxide molecule.
19) From
m= mass of solute
M= molar mass of solute
C= concentration of solute
V= volume of solution
m/M = CV
m= MCV
m= 40.0gmol-1 × 50.0/1000 × 0.200
m= 0.4 g
