ES 200 Quiz 7

What is a feature of thermohaline circulation that causes water to be pulled toward the North Atlantic?

Cold → Water liquid → Water solid (Ice)

Cold, salty, dense water falls to the bottom of the ocean. Surface water flows toward hole created by downward flow.

Which of these are soluble?

NaOH

K3PO4

PbCl2

AgNO3

BaCO3

NH4Br

CaCl2

CaCO3

NaOH, K3PO, AgNO3, NH4Br, CaCl2.

Rules of Solubility: Soluble

Compounds containing these ions are generally soluble, with specific exceptions:

• Nitrates (NO-3)

• Acetates (CH3COO-)

• Group 1 metals (Li+, Na+, K+, etc.)

• Sulfates (SO24-) — Exceptions: Calcium (CA2+), Barium (Ba2+), Lead (Pb2+), Silver (Ag+), and Strontium (Sr2+).

• Ammonium (NH4+)

• Group 17 non-metals (Cl-, Br-, I-) — Exceptions: Silver (Ag+), Lead (Pb2+), Mercury (Hg22+).

Rules of Solubility: Insoluble

Compounds containing these are generally insoluble unless paired with "NAG SAG" ions:

• Hydroxides (OH-) and Oxides (O2-): Generally insoluble, except when paired with Group 1 metals or Ammonium.

• Carbonates (CO23-), Phosphates (PO34-), and Sulfides (S2-): Generally insoluble

Which salts out of these are electrolytes?

NaOH

K3PO4

PbCl2

AgNO3

BaCO3

NH4Br

CaCl2

CaCO3

5 - NaOH, K3PO4, AgNO3, NH4Br, and CaCl2.

How to tell?

Salts are electrolytes if they are ionic compounds (metal + nonmetal) that dissolve in water to dissociate into ions. Soluble salts are strong electrolytes (fully dissociate), while insoluble salts are weak/non-electrolytes. Use solubility rules—particularly for Group 1 metal salts and nitrates—to determine if a salt is a strong electrolyte.

What is an electrolyte?

Salts that break down into ions that conduct electricity and are soluble in water.

Name these:

Na2CO3

Ca(OH)2

LiNO3

Na2CO3 - Sodium Bicarbonate

Ca(OH)2 - Calcium Hydroxide

LiNO3 - Lithium Nitrate

Give the formula for these:

Aluminum Chloride

Sodium Perchlorate

Ammonium Carbonate

Aluminum Chloride - AlCl3

Sodium Perchlorate - NaClO4

Ammonium Carbonate - (NH4)2CO3