Of the following household chemicals, which ones would be soluble, or insoluble?

Question

Cornstarch
White chalk
plaster of paris
Washing soda
epsom salt
baking soda
boric acid
table sugar
table salt.

If I tested the insolubles in iodine which ones would test positive and which ones would test negative?
baking soda?

If the solubles were tested using litmus paper which ones would change to dark blue, light blue, pink or no change?

Answer 1

Corn starch, white chalk (CaCO3), and plaster of Paris (CaSO4) are all water-insoluble. You have to qualify that, though, because everything is "slightly" soluble. Otherwise, the little bit of corn starch could not get into the water to form the blue clathrate with iodine.

The rest are water soluble. Sugar and salt would give no color change with litmus paper. Boric acid would turn pink, because H3BO3 ===> H+ + H2BO3=, etc. Epsom (MgSO4)salt would turn blue, because Mg2+ + 2H2O <===> Mg(OH)2 + 2H+. Washing soda, Na2CO3, would turn blue because CO3= + H2O <===> HCO3- + OH-. Baking soda (NaHCO3) would turn blue because HCO3- + H2O <===> H2CO3 + OH-. Baking soda also turns phenolphthalein pink but not red (I've tried it.)

Answer 2

Soluble or insoluble in WHAT?

I'll assume water.

Cornstarch would test positive with iodine.

Chalk, washing soda, baking soda would give blue using litmus paper. Boric acidwould change it to pink

Answer 3

Solubles : Washing Soda, Epsom Salt,Baking Soda, Boric Acid, Table sugar and Table salt
Insolubles : Comstarch, White Chalk and Plaster of Paris.
With Iodine only comstarch will test positive, others all will show negative test.
Washing soda will change litmus paper to dark blue.
Baking soda will change litmus paper to light blue.
Boric acid will change litmus paper to pink.
Comstarch, white chalk, Plaster of paris, table sugar , table salt and epsom salt will not change litmus paper.