Lesson 9, Topic 2
In Progress

# Information Given & not Given by a Chemical Equation

Lesson Progress
0% Complete

### Information given by a Chemical Equation

1. It gives us the reactants and products involved in the reaction.

2. The molar mass of each compound can be calculated from the relative atomic masses of the elements forming the compound.

3. It tells us the individual elements and radicals involved in the reaction eg.

$$\scriptsize CuSO_4 \: + \: BaCl_2 \: \rightarrow \; CuCl_2 \: + \: BaSO_4$$

The elements involved are Cu, S, O, Cl, Ba. The radical is SO4.

4. It gives us the direction of the reaction and whether the reaction is reversible or not.

5. It tells us the state of matter in which the substances are present as indicated by the state symbols: (s) for solid, (aq) for an aqueous solution (l) for liquid, (g) for gas.

$$\scriptsize CaCO_{3(s)} \: + \: HCl_{(aq)} \: \rightarrow \: CaCl_{2(aq)} \: + \: H_2O_{(l)} \: + \: CO_{2(g)}$$

6. Arrows can be used to show a precipitate (e.g BaSO4) being formed, or a gas (e.g H2)

e.g

i. $$\scriptsize AgNO_3 \: + \: NaCl \: \rightarrow \: AgCl \: + \: NaNO_3$$

ii. $$\scriptsize Zn_{(s)} \: + \: HCl_{(aq)} \: \rightarrow \: ZnCl_{2(aq)} \: + \: H_{2(g)}$$

### Information not given by a Chemical Equation

1. The physical state of the reaction e.g colour,

2. Speed of the reaction

3. The conditions of the reaction i.e whether the solution is concentrated or dilute or whether heating is necessary.

error: