Edexcel GCSE Chemistry Paper 1 (Foundation Tier) Review

Flashcards covering key concepts, numerical calculations, chemical equations, and experiments from GCSE Chemistry Paper 1 (Foundation Tier).

In Figure 1, what are the three states of matter represented by the boxes from left to right?

Liquid, solid, gas

What two pieces of laboratory equipment should a student use to convert solid wax into a liquid?

A Bunsen burner and a test tube

What name is given to the process when liquid left in a warm room disappears after a few days?

Evaporation

How do the movement and arrangement of water particles change when water is cooled from $10\,^\circ\text{C}$ to $-10\,^\circ\text{C}$?

The particles lose energy and move slower. They change from a randomly arranged liquid with particles sliding past each other into a fixed, regularly arranged solid lattice where particles only vibrate about fixed positions.

What is the structure of water?

Simple molecular (covalent)

Which piece of apparatus can be used to show that ammonia solution is alkaline?

A pH meter

What is one advantage of using fertilisers made from ammonia rather than using manure?

The exact nutrient ratio/composition can be controlled and known, or they are faster-acting/more concentrated.

What is the word equation for the reaction between ammonia solution and dilute phosphoric acid?

$$\text{ammonia} + \text{phosphoric acid} \rightarrow \text{ammonium phosphate}$$

What is the empirical formula of ammonium sulfate, $(NH_4)_2SO_4$?

$$N_2H_8SO_4$$

Which metal is found uncombined in the Earth's crust?

Gold

What is the word equation for the reaction when iron oxide is heated with carbon?

$$\text{iron oxide} + \text{carbon} \rightarrow \text{iron} + \text{carbon dioxide}$$

What happens to iron oxide during its reaction with carbon to form iron?

The iron oxide is reduced (loses oxygen).

Why is the starting mass of $100\,g$ of copper carbonate equal to the total mass of products formed in its thermal decomposition?

Mass is conserved in a chemical reaction because no atoms are created or destroyed.

Based on Figure 2, give two reasons why it could be more important to recycle tin than to recycle aluminium.

1. Tin is much more expensive ($£12.60$ per $kg$ compared to $£1.31$ per $kg$ for aluminium).
2. Tin is much rarer in the Earth's crust ($0.0002\%$ compared to $8\%$ for aluminium).

What is an electrolyte?

An ionic compound in a molten state or dissolved in water that conducts electricity and is decomposed by it.

Using the data in Figure 5, calculate the mass of copper deposited on the cathode.

$$1.57\,g - 1.28\,g = 0.29\,g$$

Identify the products formed at the anode and cathode when molten potassium iodide is electrolysed.

Anode: Iodine ($I_2$) Cathode: Potassium ($K$)

In the decomposition $2NaF \rightarrow 2Na + F_2$, where relative formula mass of $NaF = 42$ and relative atomic mass of $Na = 23$, calculate the maximum mass of sodium formed from $168\,g$ of sodium fluoride.

$$\text{Mass of } Na = \frac{23}{42} \times 168\,g = 92\,g$$

Solder is made by mixing $22.5\,g$ of lead with $15.0\,g$ of tin. Calculate the percentage of tin in this solder.

$\text{Total mass} = 22.5\,g + 15.0\,g = 37.5\,g$$\text{Percentage of tin} = \frac{15.0\,g}{37.5\,g} \times 100 = 40\%$

Why does an iron bucket coated in zinc not rust even when scratched to expose the iron?

Zinc is more reactive than iron, so zinc corrodes sacrificially instead of the iron.

What is the balanced symbol equation for the reaction of magnesium with oxygen to form magnesium oxide?

$$2Mg + O_2 \rightarrow 2MgO$$

Calculate the relative formula mass of calcium nitrate, $Ca(NO_3)_2$, given relative atomic masses $Ca = 40$, $N = 14$, $O = 16$.

$$M_r = 40 + (14 \times 2) + (16 \times 6) = 40 + 28 + 96 = 164$$

Oxide R of lead has the empirical formula $PbO$. Oxide S contains $0.207\,g$ of lead combined with $0.032\,g$ of oxygen. Calculate the empirical formula of oxide S to show it differs from R. (Relative atomic masses: $Pb = 207$, $O = 16$)

$\text{Moles of } Pb = \frac{0.207}{207} = 0.001\,mol$$\text{Moles of } O = \frac{0.032}{16} = 0.002\,mol$$\text{Ratio } Pb : O = 1 : 2 \rightarrow PbO_2$ Since $PbO_2 \neq PbO$, oxide S has a different empirical formula.

Why is the start line drawn in pencil rather than in ink in paper chromatography?

Pencil is insoluble in the solvent, so it will not dissolve or run up the paper and interfere with the chromatogram.

In chromatography, a blue spot moves $14.5\,cm$ while the solvent front moves $15.3\,cm$. Calculate the $R_f$ value to 2 significant figures.

$$R_f = \frac{14.5\,cm}{15.3\,cm} = 0.9477... \approx 0.95$$

Calculate the concentration in $g\,dm^{-3}$ of a solution made by dissolving $4.3\,g$ of sodium hydroxide in water to make $250\,cm^3$ of solution.

$\text{Volume} = \frac{250\,cm^3}{1000\,cm^3\,dm^{-3}} = 0.25\,dm^3$$\text{Concentration} = \frac{4.3\,g}{0.25\,dm^3} = 17.2\,g\,dm^{-3}$

Write the balanced chemical equation for the reaction of dilute sulfuric acid ($H_2SO_4$) with sodium hydroxide ($NaOH$).

$$2NaOH + H_2SO_4 \rightarrow Na_2SO_4 + 2H_2O$$

Why does solid calcium chloride not conduct electricity, whereas molten calcium chloride does?

In solid calcium chloride, the ions are held in fixed positions in a lattice and cannot move. In molten calcium chloride, the lattice breaks down, allowing ions to move freely and carry electrical charge.

Why does diamond not conduct electricity, whereas zinc does?

Diamond has a giant covalent structure where all valence electrons are held in covalent bonds with no free charged particles. Zinc has metallic bonding with delocalised electrons that move freely to carry electrical charge.

In an experiment, the theoretical yield of lead sulfate was $2.85\,g$, but only $2.53\,g$ was obtained. Calculate the percentage yield to 2 significant figures.

$$\text{Percentage yield} = \frac{2.53\,g}{2.85\,g} \times 100 = 88.77\% \approx 89\%$$

State whether ammonium chloride, lithium sulfate, and magnesium carbonate are soluble or insoluble in water.

Ammonium chloride: Soluble Lithium sulfate: Soluble Magnesium carbonate: Insoluble