Question

1. If 12.3 mL of 0.25 M HNO3 is required to titrate 18.4 mL of Ba(OH) 2 , what is the molarity of the Ba(OH)2 solution?

2. The chemical equation for the reaction of iron metal with hydrochloric acid is Fe( s) + 2HCl(aq)→FeCl2(aq) + H2(g) Will the rate of this reaction (1) increase, (2) decrease, or (3) remain the same when each of the following actions occurs?

a. The temperature is increased

b. The solution is stirred

c. The concentration of the acid is increased

d. The iron is ground into a powder

Answer 1

1)Molarity of Acid, M_a = 0.25 M

Molarity of base, M_b = ?

Volume of acid, V_a= 12.3 mL

Volume of V_b = 18.4 mL

We know that,

M_aV_a = M_bV_b

or, M_b = M_aV_a / V_b = (0.25 M x 12.3mL) / 18.4 mL = 0.167 M

Thus, molarity of Ba(OH)₂ = 0.167 M