y11 specialist chem introduction

What is the Johnstone’s Triplet?

A model that helps to better understand chemistry ideas and concepts, and allows us to make connections on three levels so that we can explain the chemistry happening.

What are the three levels of the Johnstones Triplet?

Sub- Microscopic, Macroscopic, Symbolic

What is Macroscopic?

The level of what can be seen- observations on what can be seen, smelt, heard, touched.

What is symbolic?

The level of what is unseen, such as word equations, mathematical formulas, graphs and diagrams

What is Sub-Microscopic?

The level of the unseen atomic world: atoms, ions, molecules, polarity, geometry

What is an atom?

basic building block of all matter in the universe

What is a ion?

An atom/molecule that has an electrical charge

What is a molecule?

Two or more atoms bonded together

What is the first stage of the Copper Cycle?

Copper looks pinkish brown, malleable, solid. Add nitric acid. Release of brown gas and vigorous effervesesnse. Solid metal dissapears, final solution of one blue liquid.

What is actually happening in the first stage of the Copper Cycle?

Copper atoms are reacting to form copper ions (Cu2+). Copper+Nitric acid → copper nitrate +water +nitrogen dioxide. Cu+HNO3 —> Cu(NO3)2 + 2H2O + 2NO2

What is the second stage of the Copper Cycle?

+Colorless NaOH. Formation of bright blue gelatonous precipitate, which settled below a colorless solution. Blue Cu2+ ions moved from Cu(NO3)2 solution into a precipitate of Cu(OH)2 + 2NaNO3

What is actually happening in stage 2 of the Copper Cycle?

Copper Nitrate + Sodium Hydroxide —> Copper Hydroxide + Sodium Nitrate. Cu(NO3)2 + 2NaOH —→Cu(OH)2 + 2NaNO3

What is happening in stage 3 of the copper cycle?

Blue precipitate changed into a fine black powder ( + water and heat). Settled as a sediment underneath a colorless solution (supernatent)

What is actually happening in stage 3 of the Copper Cycle?

Copper Hydroxide ——> Copper Oxide + Water Cu(OH)2——>CuO + H2O

What is happening in stage 4 of the Copper Cycle?

Black powder (Copper Oxide) + sulfric acid. Substance turns blue and black powder dissapears. bubbles of CO2 gas are released. Copper now in a solution as blue as Cu2+ ions.

What is actually happening in stage 4 of the copper cycle?

Copper Oxide + Sulfric acid → copper sulfate + Water. CuO+ H2SO4 → CuSO4 + H2O

What happens in stage 5 of the copper cycle?

Add Zinc and swirl. Dull, gray zinc turns black/ dark brown. Blue colior of the solution fades. pink/brown solid appears at the bottom of tube. Copper now brown Cu atoms.

What is actually happening in stage 5 of the Copper Cycle?

Copper Sulfate + Zinc metal → zinc Sulfate + Copper. CuSO4 + Zn → ZnSO4 + Cu

What is a precipitation reaction?

A chemical process where two clear, dissolved solutions (usually aqueous), are mixed together, resulting in the form of a solid, insoluble substance..

What is a displacement reaction?

A chemical process where a more reactive element replaces a less reactive element within a compound.

What is an example of a displacement reaction reffering to the Copper Cycle?

Stage 5, in which Cu2+ ions gain electrons from the zinc, reduced to normal copper atoms, coming out of the solution as copper metal.

What is an example of a precipitation reaction reffering to the copper Cycle?

Stage 2, Cu2+ ions stay as Cu2+ ions, not losing or gaining electrons, instead combining with carbonate ions to form an insoluble liquid. Now the copper ions are trapped inside a solid precipitate.

In a displacement reaction, Zinc is more reactive then Copper, which means it is better at losing electrons

Free answer :)

What do precipitation reactions depend on?

Solubility

What are the solubility rules?

Always Soluble

• Group 1 Metals

• Ammonium

• Nitrates and Acetates

Generally Soluble

• Halides

• Sulfates

Generally Insoluble

• Hydroxides

• Carbonates, Phosphates, and Sulfides

In addition to specific ions, the golden rule of solubility is "like dissolves like." Polar substances dissolve in polar solvents, and nonpolar substances dissolve in nonpolar solvents