Stainless steel is used for making?
magnets
tools
coins and medals
moving parts of clocks
Correct answer is B
- Stainless steel is an alloy of iron, nickel and chromium. It is used in making cutlery, tools and surgical equipment.
A compound gives an orange-red color to non-luminous flame. This compound is likely to contain?
Na+
Ca2+
Fe3+
Fe2+
Correct answer is B
- Calcium when introduced into the flame, it will produce brick red / red-orange colour.
When iron is exposed to moist air, it gradually rusts. This is due to the formation of?
hydrate iron (III) oxide
anhydrous iron (III) oxide
anhydrous iron (II) oxide
hydrate iron (II) oxide
Correct answer is A
Rusting is an oxidation reaction. The iron reacts with water and oxygen to form hydrated iron(III) oxide, which we see as rust.
A constituent common to bronze and solder is?
lead
silver
copper
tin
Correct answer is D
- bronze, alloy traditionally composed of copper and tin.
- Solder is an alloy, made from the elements, tin and lead.
Which of the following is used in rocket fuels?
HNO3
CH3COOH
H2SO4
HCl
Correct answer is A
- Due to its unique powerful oxidizing nature, Nitric acid is often used in rocket fuels as a propeller
NB: Ethanol (not Ethanoic acid) is used alone or mixed with petrol as fuel for racing cars and in rockets.