Question

2. Write a balanced chemical equation for the reaction of one anion in each of the categories in question 1. I am given the following anions: SO4^2-, CO3^2-, NO2-, CL-, Br-, I-, and NO3-.

A. a precipitation reaction

B. a redox reaction

C. an acid-base reaction

D. a gas-forming reactio

Answer 1

a)

precipitation implies solid formation, from th elist, only cations of SO4-2 and CO3-2 can form precipitates

Ba+2 + SO4-2 --> BaSO4(s)

Ca+2 + CO3-2 --> CaCO3(s)

b)

redox reaction requires change of electrons, so

Br2(aq) + 2I-(aq) --> I2(aq) + 2Br-(aq)

Bromine goes from 0 in Br2, to -1 in Br-

I goes form -1 in I- to 0 in I2

c)

acid base reaction requires acid --> HCl, and base, NAOH

then

HCl(aq) + NAOH = NaCl(aq) + H2O(l)

d)

choose CO3-2, since it gan from CO2(g) when neutralized:

2HCl(aq) + CaCO3(aq) --> CaCl2(aq) + H2O(l) + CO2(g)