chemistry homework help!?

1. which of the following statements correctly describes the hydronium-hydroxide balance in the given solutions?

A) In bases, [OH-] is greater than [H3O+]

B) In bases, [OH-] = [H3O]

C) In neutral solutions, [H3O +] = [H2O]

D) In acids, [OH-] is greater than [H3O+]

E) In bases, [OH-] is less than [H3O+]

2. Which of the following is a neutralization reaction?

A) KCl + NaNO3 ---> KNO3 + NaCl

B) 4Na +O2 ----> 2Na(sub2)O

C) H2O + SO3 -----> H(sub2)SO4

D) HNO3 + KOH ---> H2O + KNO3

E) 2NO2 ----> 2NO + O2

3. the neutralization between Al(OH)3 and HNO3 produces the salt with the formula:

A) AlH2

B) NO(sub3)OH

C) H2O

D) Al(NO3)3

E) ALNO3

4. which of the following is a buffer system?

A) HCl and NaOH

B) H2O and HCl

C) NaCl and NaNO3

D) H(sub2)CO3 and KHCO3

E) NaCl and NaOH

5. How many milliliters of 0.400 M NaOH are required to completely nutralize 20.0mL of 0.200 M HCl?

A) 50.0 mL

B) 40.0 mL

C) 0.100 mL

D) 10.0 mL

E 20.0 mL

* Please explain + show work