Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

Write the net ionic equation for the CaH_2/H_2O reaction in Part B. Write the ne

ID: 507888 • Letter: W

Question

Write the net ionic equation for the CaH_2/H_2O reaction in Part B. Write the net ionic equation for the products of the reaction in question 1 reacting with the solution you chose in Part B (NaC_2H_3O_2, NaCl, NaHSO_4). A few mL of ___ M HCl are added to 20 mL of ____ M NaC_2H_3O_2: a. Will the initial pH of the _____ M NaC_2H_3O_2 be greater than, or equal to 7? A. Greater than 7 B. Less than 7 C. Equal to 7 b. As HCl is added to the ___ M NaC_2H_3O_2, will the pH of the solution increase, decrease, or remain unchanged? A. Increase B. Decrease C. Remain unchanged c. write the net ionic equation for the reaction between the HCl solution and the NaC_2H_3O_2 solution A solution has a hydroxide concentration of _____ M. Calculate: a. pH b. pOH c. [H^+]

Explanation / Answer

Answer:

1. The net ionic reaction of CaH2/H2O is

CaH2(s) + 2 H2O(l) Ca2+(aq) + 2 OH-(aq) + 2 H2(g).

OR

CaH2(s) + 2 H2O(l) Ca(OH)2(aq) + 2 H2(g)

2.Ca(OH)2 reacts with NaC2H3O2, NaCl and NaHCO3

a.Ca(OH)2 + 2NaC2H3O2------->Ca(C2H3O2)2 + 2Na(NO3)

b.Ca(OH)2 + 2 NaCl ---------> CaCl2 + 2 NaOH

c.NaHCO3 + Ca(OH)2 ------>CaCO3 + H2O + NaOH
NaHCO3 + Ca(OH)2 --------->CaCO3 + H2O + Na2CO3

3.

a. Initia pH of 0.15 M NaC2H3O4 is less than 7

C2H3O2- in water --> HC2H3O2 & OH-

K = [HC2H3O2] [OH-] / [C2H3O2-]

K hydrolysis = K water / K HC2H3O2 = 1 X 1014 / 1.8 X 10-5 = 5.55 X 10-10
5.55 X 10-10 = [x] [x] / [0.15]

x = [OH-] = 8.23 X 10-11 molar

pOH = 10.07

pH = 14 - pOH

pH = 3.92( Acidic)

b. HCl is added to NaC2H3O2 pH of solution decreases because following acid formation reaction occur

HCl + NAC2H3O2 ---------> HC2H3O2 + NaCl

c.Reaction of HCl with NaC2H3O2

HCl + NAC2H3O2 ---------> HC2H3O2 + NaCl

4 . [OH-] =0.010

a. pOH = -log[OH-]

pOH=-log[0.010]

=2

pH + pOH =14

pH=12

b.

pOH = -log[OH-]

pOH=-log[0.010]

=2

c.

pH=12

pH=-log[H+]

[H+]=1 X 10-12