1.1. Iron and titanium are both metals with a variety of industrial uses. They are commonly found in and extracted from ores using carbon monoxide.

State why iron and titanium are not extracted directly from their ores using carbon.

1.2. Strontium salts have a number of applications such as fireworks, flares, glow in the dark paint and toothpaste for sensitive teeth. The strontium required for these salts can be extracted from the ore strontia, SrO, by displacement with powdered aluminium in a vacuum.

i) Write a balanced symbol equation, including state symbols, for the reaction of strontia with aluminium.

ii) State the role of the aluminium in this reaction.

iii) The standard enthalpy change for this extraction of strontium is 99.3 kJ mol^-1 and the standard enthalpy of formation of aluminium oxide is -1676.7 kJ mol^-1.

Use this information to calculate the standard enthalpy of formation of strontia.

1.3. Vanadium is an important metal in the alloy industry. When alloyed with iron or steel, the vanadium alloy is strong and resistant to corrosion. These alloys are often used to make parts for machinery such as axles, gears and crankshafts. When combined with gallium, it forms superconductive magnets and with aluminium and titanium, it forms a very strong alloy that is used in dental implants and jet engines.

Vanadium is commonly found in different ores such as magnetite, vanadinite and patronite. The vanadium is commonly extracted from these ores by reduction and displacement. 

Vanadium can be extracted by the reduction of vanadium pentoxide, V2O5, with calcium at high temperatures, according to the following equation.

V₂O₅ (s) + 5 Ca (s) → 2 V (s) + 5 CaO (s) 

i) Explain the effect that increasing the pressure will have on the reduction of vanadium.

ii) The enthalpy of formation of vanadium pentoxide is -1560 kJ mol^-1 and the standard enthalpy change for the reaction is -1615 kJ mol^-1.

Use this information to calculate the enthalpy of formation of calcium oxide.

1.4. Manganese is too brittle for use as a pure metal, so it is often alloyed with other metals. Manganese is used in steel to increase the strength and resistance to wear. Manganese steel (13% Mn) is extremely strong and used for railway tracks, safes and prison bars. Alloys of 1.5% manganese with aluminium are used to make drinks cans due to the improved corrosion resistance of the alloy.

Manganese is extracted from different ores by reduction with carbon monoxide.

Mn₂O₃ (s) + 3 CO (g) → 2 Mn (s) + 3 CO₂ (g)

Although this is not a reversible reaction, an equilibrium is established in terms of the yield and rate of reaction.

Table 1 shows some enthalpy of formation data.

Table 1

Use the information to explain how temperature can be altered to increase the yield of the reaction and explain the effect that this would have on the rate of reaction.