A) Select the strongest acid:H2Te, GeH4, AsH3, H2S, SiH3

B) Base with the highest pKb:ClO -, BrO-, BrO2- , BrO4-, ClO2-

C) Acid with the lowest pKa: H3PO3, H3PO4, H3ASO4, H2SbO3 H2SbO4

D) Acid with the highest pKa: HClO4, HIO2, HBrO3, HBrO2, HBrO4

E) Arrange the following compounds in the order of increasing basic strength: CsOH, NH3, CH3NH2, BrNH2

F) Arrange the following compounds in the order of increasing acid strength: HIO, HBrO, HClO

(A). H2S.

(B). BrO-.

(C). H2SbO3 .

(D). HClO4.

(E). CH3NH2.

(F). HClO > HBrO > HIO.

Explanation:

(A). The strongest acid is H2S because it has the lowest atomic size. If we move from the left side of the periodic table to the right side of the periodic table the atomic size decreases. As the atomic size decreases, it will be easier for H^+ ion to be released. Therefore, the ease of releasing Hydrogen ion makes H2S more acidic than the others in this group.

(B). BrO- is more basic because of bond pair - lone pair repulsion. BrO2- , BrO4-, and ClO2- exhibit resonance and therefore, they do not possess good basic features.

(C). H2SbO3 has the lowest pKa because the atomic size of Sb is greater than As and P , As is greater than P. This means that It is more difficult to remove Hydrogen ion from Sb.

(D). HClO4 is the Acid with the highest pKa because of high resonance.

(E). CH3NH2 is more basic because it has the highest electron Density. In BrNH2, the bromine ion reduces the electron Density.

(F). In halogens, as one goes down the group in the periodic table the acidic properties decreases, hence, HClO > HBrO > HIO.

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