NESA Chemistry Communicating

Equation:
$Cu(s) + Cl_2(g) \rightarrow CuCl_2(s)$

Observation:
Reactants – salmon pink solid and greenish-yellow gas
Products – green solid forms on solid and greenish-yellow gas decolourises

Equation:
$2 C_8H_{18}(g) + 17 O_2(g) \rightarrow 16 CO(g) + 18 H_2O(g)$

Observation:
heat evolved/temperature increases/(orange) flame
Any one of the following (to match equation):

• black solid/soot formed
• colourless gases mixed

Equation:
$\text{Fe(s)} + \text{Cu}^{2+}\text{(aq)} \rightarrow \text{Cu(s)} + \text{Fe}^{2+}\text{(aq)}$

Observed colour change/s:

• a grey/silver solid and blue solution
• form a salmon pink solid (solution decolourises/pale green)

Equation
$\text{Ca(HCO}_3)_2\text{(s)} + 2 \text{H}^+\text{(aq)} \rightarrow \text{Ca}^{2+}\text{(aq)} + 2 \text{H}_2\text{O(l)} + 2 \text{CO}_2\text{(g)}$

Observed colour change/s:

• white solid and colourless solution
• solid dissolves/reacts and there is effervescence (bubbling)

Equation:
$2 \text{Br}^-\text{(aq)} + \text{Cl}_2\text{(g)} \rightarrow \text{Br}_2\text{(aq)} + 2 \text{Cl}^-\text{(aq)}$

Observed colour change/s:

• greenish-yellow gas is bubbled through a colourless solution
• forms an orange solution