Chemistry Multiple Choice Questions on “Application of d and f-Block Elements”.
1. Which metal is used in an aircraft turbine engine?
a) Iron
b) Thorium
c) Titanium
d) Neodymium
Answer: c
Clarification: Titanium is one such material which plays a pivotal role in modern jet engine design. Its strength to weight ratio and resistance to extreme heat make it the ideal candidate for aerospace applications. Hence, it is used in aircraft turbine engines.
2. Mild steel is used in construction.
a) True
b) False
Answer: a
Clarification: Plain Carbon Steel is the most common type of steel used in building construction, which is also known as mild steel. It is incalculably strong and durable, and ensures a sturdy built and used in various type of construction.
3. Which metal is used as an electroplated protective coating?
a) Plutonium
b) Chromium
c) Nickel
d) Iron
Answer: b
Clarification: Chrome plating (less commonly chromium plating), often referred to simply as chrome, is a technique of electroplating a thin layer of chromium onto a metal object. The chromed layer can be decorative, provide corrosion resistance, ease cleaning procedures, or increase surface hardness.
4. Which metal is used in making electrical fibres?
a) Actinium
b) Nickel
c) Thorium
d) Tungsten
Answer: d
Clarification: The melting point of Tungsten (W) is very high (3422°C). It has the highest melting point among all the metals. This property of Tungsten makes it excellent for use as filaments in light bulbs as it can resist high temperatures.
5. Silver bromide is used in photography.
a) True
b) False
Answer: a
Clarification: Silver bromide (AgBr), a soft, pale-yellow, water-insoluble salt well known (along with other silver halides) for its unusual sensitivity to light. AgBr is widely used in photographic films and is believed by some to have been used for making the Shroud of Turin.
6. Which of the following metal does not form a coloured salt?
a) Thorium
b) Zinc
c) Bronze
d) Cobalt
Answer: b
Clarification: Zinc has no unpaired electrons in its d orbital and has a stable fully filled d orbital. Hence, due to the absence of unpaired electrons in Zinc, it can show no specific colouration in its salts. All salts and solutions of Zinc are always white due to this fact.
7. Which of the following is used as a nuclear fuel?
a) Cobalt
b) Zinc
c) Iron
d) Uranium
Answer: d
Clarification: Uranium (atomic no. 92, symbol-U) is used as nuclear fuel. Its salts are used in the glass industry (for imparting green colour), textile industry, ceramic industry and in medicines. Natural uranium has three major isotopes.
8. Which of the following has the highest density?
a) Os
b) Zn
c) Cr
d) Cd
Answer: a
Clarification: Osmium is the densest naturally occurring element, with an experimentally measured (using x-ray crystallography) density of 22.59 g/cm3. Its atoms are packed together more tightly in the solid form than other metals.
9. Which of the following element has the highest melting point?
a) Co
b) Zn
c) Ni
d) Cr
Answer: d
Clarification: Of all the 3d transition elements, chromium has the highest melting point. More the number of unpaired electrons in the d-block element, stronger is the metallic bond formation. Since chromium contains more number of unpaired electrons, it has the highest melting point.
10. What is the end product formed when KMnO4 reacts with HCl?
a) Brown fumes
b) Dark green gas
c) Greenish yellow gas
d) Dense white fumes
Answer: c
Clarification: Potassium permanganate (KMnO4) reacts with hydrochloric acid(HCl) to form potassium chloride, manganese chloride, chlorine and water. Here, one of the products formed, chlorine, is a greenish yellow gas. It has a pungent smell and is toxic.