Chemical Changes Flashcards

What are common examples of strong acids?

Hydrochloric acid (HCl), Sulphuric acid (H2SO4), and Nitric acid (HNO_3).

What is the typical pH range for acids?

1-6.

Distinguish between strong and weak acids.

Strong acids fully dissociate in solution, while weak acids partially dissociate in solution.

What type of ions do acids produce in solution?

H^+ ions.

What is an example of an alkali?

Sodium hydroxide (NaOH).

What is an example of an alkali?

Sodium hydroxide (NaOH).

What is the typical pH range for alkalis?

8-14.

What type of ions do alkalis produce in solution?

OH^- ions.

What is the definition of a neutralisation reaction?

An acid reacts with an alkali to produce a salt and water.

Write the ionic equation for neutralisation.

H^+ + OH^-
ightarrow H_2O

How are unreactive metals typically found, and what are some examples?

They are found native (uncombined/pure). Examples include gold and silver.

How are metals more reactive than carbon extracted?

Via electrolysis.

How are metals less reactive than carbon extracted?

By displacement/reduction through heating with carbon.

Provide an example of reduction by heating with carbon.

Iron oxide + carbon
ightarrow iron + carbon monoxide, where iron oxide is reduced (losing oxygen) and carbon is oxidised (gaining oxygen).

What is a redox reaction?

It is a reaction where oxidation and reduction take place at the same time.

Define oxidation in terms of oxygen and electrons.

Oxidation is the gaining of oxygen or the losing of electrons.

Give a half equation illustrating oxidation (loss of electrons).

Na
ightarrow Na^+ + e^-

Define reduction in terms of oxygen and electrons.

Reduction is the losing of oxygen or the gaining of electrons.

Give a half equation illustrating reduction (gain of electrons).

Zn^{2+} + 2e^-
ightarrow Zn

List the elements in the reactivity series from most to least reactive.

Potassium, Sodium, Calcium, Magnesium, Carbon, Zinc, Hydrogen, Iron, Tin, Copper, Silver, Gold.

What defines a displacement reaction?

When a more reactive element takes the place of a less reactive element in a compound.