Can someone please check-over my answers to these Chemistry problems?

Question

(My answers are in bold.)

Which of these acids is diprotic?

A. HNO3

B. H2CO3

C. H3PO4

D. HSO4–

E. All of the Above

Which of these acids is triprotic?

A. HNO3

B. H2CO3

C. H3PO4

D. HSO4–

E. None of the Above

Which of these reactions involves an acid and a covalent base?

A. HF + KOH → H2O + KF

B. H2SO4 + 2NaOH → Na2SO4 + 2H2O

C. HNO3 + Al(OH)3 → Al(NO3)3 + H2O

D. H2SO4 + 2H2O → 2H3O+ + SO42–

E. chemical equilibrium

600.0 mL of H₂SO₄ is titrated with a 6.0 M solution of NaOH and requires only 6.8 mL of NaOH to reach the endpoint. According to the unbalanced equation H₂SO₄ + NaOH → H₂O + Na₂SO₄, what is the concentration of the H₂SO₄?

A. 0.041 moles

B. 0.021 moles

C. 0.034 M

D. 21 M

E. 34 M

When 45.0 mL of 4.8 M HCl reacts with an excess of Mg(OH)₂, how many grams of Magnesium Chloride (MgCl₂) are produced, given the unbalanced equation HCl + Mg(OH)₂ → H₂O + MgCl₂?

A. 0.11 moles

B. 0.11 g

C. 1.1 moles

D. 1.1 g

E. 10. g

Answer 1

which of these acids are diprotic

a diprotic acid has 2 H in the acid compound

H2CO3 = carbonic acid has 2moles H+ per 1 mole CO3-

Which of these is triprotic

a triprotic acid has 3 H in the acid compound

H3PO4 has 3 H+ per PO4-3

Which of these involves an acid with a covalent base

it would be H2SO4 + 2H20 >>>2H30+ + SO4-2

water is a covalent compound and it acts as a base by accepting the H+ from H2SO4

Its conjugate acid is the Hydronium ion H3O+

Titration problem

H2SO4 + 2NaOH >>> 2H2O + Na2SO4

moles NaOH 6mol/L x 0.0068L = 0.04 moles

using the molar ratio of NaOH to HsSO4

0.04 mol NaOH x 1mol H2SO4/2mol NaOH = 0.02 mol H2SO4

Concentration of H2SO4 = 0.02 mol/.6L = 0.034M

Stoichiometry

2HCl + Mg(OH)2 >>>>> 2H20 + MgCl2

mol HCl 4.8.mol/L x 0.045L = 0.216 mol

using molar ratios

0.216 mol HCl x 1mol MgCl2/2mol HCl = 0.108 mol MgCl2

grams MgCl2 = 0.106 mol MgCl2 x 95.1 grams/ 1 mol MgCl2 = 10.27.grams