v-t graphs

diff --git a/chem/water.md b/chem/water.md
index 34beb005a14d29d2e51b190dd353314d1628ac96..15e95f6410b3f46ac683b143c779843291aa4e26 100644 (file)
--- a/chem/water.md
+++ b/chem/water.md
@@ -79,6 +79,8 @@
 - special concentration unit in mol / L (abbbreviation M)
 $$c={n \over v}$$
 
+$$c_1v_2=c_2v_2=n\quad\leftarrow(\operatorname{constant})$$
+
 | Quantity               | Symbol  | Unit          |
 | ---------------------- | ------- | ------------- |
 | molar mass             | $M$     | g / mol       |
@@ -87,6 +89,7 @@ $$c={n \over v}$$
 
 ## Precipitation reactions
 Ions in solution combine to form a new compound.
+Occurs when concentration exceeds solubility.
 Precipitation reactions happen when water cannot dissociate ionic lattice structure.
 Precipitate (product):
 - generally insoluble in water