4NA Sci(Chem) Topics

Which statement is true of an alloy?

• It is a compound formed from two or more metals.
• It is not as hard as pure metal.
• It corrodes easily.
• It is a mixture of a metal with one or more other elements.

What is formed by the reaction of sodium with cold water?

• Sodium oxide and hydrogen
• Sodium hydroxide and hydrogen
• Sodium hydroxide and oxygen
• Sodium hydroxide only

Which metal does not react with cold water but does react on heating with steam to produce hydrogen gas?

• Calcium
• Copper
• Sodium
• Zinc

In the extraction of iron from haematite, which substance removes impurities from the blast furnace?

• Carbon
• Calcium silicate
• Calcium oxide
• Calcium carbonate

List the metals in order of increasing reactivity.

• Y, Z, X
• Z, X, Y
• X, Z, Y
• X, Y, Z

silica (sand) SiO2 is a/an __________ oxide.

• acidic
• amphoteric
• alkaline
• neutral

Rust forms most readily around an iron object if it is surrounded by __________.

• distilled water
• dry air
• seawater
• tap water

The relative formula mass of a chloride, XCl, is 58.5. The relative atomic mass of X is .

• 11
• 17
• 23
• 35.5

The mass of one mole of oxygen atoms is 16 g. What is the mass of one mole of oxygen gas?

• 8g
• 16g
• 24g
• 32g

Which list shows a homologous series? 

• A
• B
• C
• D