9.1 Properties, Uses & Alloys of Metals

Tungsten is a useful metal. It has the chemical symbol W.

One method of extracting tungsten involves heating a tungsten compound, WO₃, with hydrogen. Water is also produced. Write the balanced symbol equation for this reaction.

Identify what has been reduced. Give a reason for your answer.

Extended Only

Tungsten alloyed with nickel and copper can be used to make protective covers for electrical sensors and missile guidance systems. Explain why this alloy is stronger than pure titanium. 

Separate: Chemistry and Extended Only

An ore of tungsten is Scheelite. The composition of this ore is 13.9% of calcium, 63.9% of tungsten and the remainder is oxygen. Calculate the empirical formula for this ore of tungsten.

Steel is formed from iron and carbon and is widely used in the construction industry.

Extended Only

Both iron and steel have typical metallic structures - a lattice of positive ions and a sea of electrons.

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Brass is an alloy of two metals, copper and zinc.

Which statement is correct?

Tick one box.

Separate: Chemistry and Extended Only

Acid digestion is a method used to dissolve metals into a solution which can then be analysed to determine the composition of the metal.

A 3.00 g sample of an aluminium alloy was reacted with an excess of concentrated nitric acid. The resulting mixture was made up to 250 cm³ with distilled water and analysed. The concentration of aluminium ions in the 250 cm³ solution was found to be 0.36 mol/dm³.

Calculate the percentage composition by mass of aluminum in the 3.00 g sample of aluminum alloy.

[A_r (Al) = 27]

This question is about metals and non-metals.

Compare the properties of metals and non-metals.

The Group I metals exhibit some properties that the majority of metals do not share.

Give one example of a property of Group I metals that is different from most other metals.

For each of the metals below, complete the table to identify a use of the metals and state the most important property of the metal that makes it suitable for that use.

Extended Only

An aluminium alloy containing 0.7% magnesium and 0.4% silicon by mass is used for making masts for sailing boats.

Calculate the number of moles of magnesium and silicon present in a mast with a mass of 17 kg.

[A_r (Mg) = 24;      A_r (Si) = 28]

Some metals react with cold water.

Give the balanced symbol equation for the reaction of calcium reacting with water. Include state symbols.

Separate: Chemistry and Extended Only

Using oxidation numbers, show that calcium is oxidised during the reaction with water.

A student added 20 cm³ of dilute hydrochloric acid to two boiling tubes. To one of the boiling tubes they added a small piece of calcium and to the other they added a small piece of magnesium.

State two observations that the student would make and how the observations would differ between the two boiling tubes.

The student had added the exact amount of magnesium required to react with the hydrochloric acid used. After carrying out the experiment, the student accidentally added some more magnesium. The student was surprised that the extra magnesium still reacted although the reaction was a lot slower. 

Explain these observations. Include an equation in your answer.

Extended Only

Gallium is a metallic element in Group III. It has similar properties to aluminium.

Extended Only

Give the formula of

Extended Only

Gallium(III) oxide, Ga₂O₃, is amphoteric.

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Alloys of gallium and other elements are often more useful than the metallic element itself.

Suggest two reasons why alloys of gallium are more useful than the metallic element.

Brass is an alloy which contains zinc.

Extended Only

In an experiment to investigate the rate of rusting of steel, three pieces of steel were used. One piece of steel was completely coated with copper, one piece was completely coated with zinc and the third piece was left uncoated. All three pieces were left exposed to the atmosphere.

Iron from the blast furnace is impure. It contains about 4% carbon and 0.5% silicon. Most of this impure iron is used to make mild steel, an alloy of iron containing less than 0.25% carbon.

A jet of oxygen is blown through the molten iron in the presence of a base, usually calcium oxide. Explain how the percentage of carbon is reduced and how the silicon is removed. 

Extended Only

Both iron and steel have typical metallic structures - a lattice of positive ions and a sea of electrons.

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[2]

Vanadium is a transition element.

An atom of the most common isotope of vanadium can be represented as .

Complete the following table to show the number of protons, electrons and neutrons in each particle.

The major use of vanadium is to make vanadium steel alloys.

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Two of the oxidation states of vanadium are +3 and +4.

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