Which one of the following statements is correct?
(a) Bordeaux mixture consists of sodium sulphate and lime.
(b) Zinc amalgams are used as a dental filling
(c) Liquid sodium is employed as a coolant in nuclear reactors
(d) Calcium carbonate is an ingredient of tooth paste.
Liquid sodium is employed as a coolant in nuclear reactor. Liquid sodium is an effective coolant which absorbs heat because of high specific heat.
Consider the following statements:
The purpose of adding sodium sulphate and sodium silicate to the detergent in a washing powder is-
- To keep the washing powder dry
- To maintain the alkalinity of the powder
Which of these statements is/are correct?
(a) Only 1
(b) Only 2
(c) Both 1 and 2
(d) Neither 1 nor 2
The purpose of adding sodium sulphate and sodium silicate to the detergent in washing powder is to keep the washing powder dry and to maintain the basically (Alkalinity) of the powder.
In an atom, the order of filling up of the orbitals is governed by-
(a) Hund’s rule
(b) Aufbau’s principle
(c) Pauli’s exclusion principle
(d) Heisenberg’s uncertainty principle
The order of filling up of the orbitals is governed by Aufbau’s principle, whichconveys that electrons are added to an atom one at a time, starting with lower energy orbital until all the electrons have been placed in an appropriate orbitals.
Match List – I with List – II and select the correct answers using the codes given below the lists:
List – I (Characteristic)
A. Zero Mass
B. Fractional charge
C. Fractional spin
D. Integral spin
List – II (Particle)
Codes: A – B – C – D
(a) 2 – 3 – 4 – 1
(b) 2 – 3 – 1 – 4
(c) 3 – 2 – 1 – 4
(d) 3 – 2 – 4 – 1
Zero Mass – Neutrino
Fractional charge – Quark
Fractional spin – Positron
Integral spin – Photon
Positron is antiparticles of electron. Neutrino is antiparticle of neutron. Quark has fractional charge.
Photons show integral spin.
Which one of the following elements is alloyed with iron to produce steel which can resist high temperatures and also have high hardness and abrasion resistance?
Chromium is generally mixed with iron to produce steel, which can resist high temperature and also have high hardness and abrasion resistance. Hardness of steel depends on the percentage of chromium.
Which of the following was used as a chemical weapon in the First World War?
(a) Mustard gas
(b) Hydrogen cyanide
(c) Water gas
(d) Carbon monoxide
Mustard gas was widely used as a chemical weapon in the First World War. Chemical weapons effect sense system of a person leading to asphyxiation and ultimately death.
Which one of the following is used as an anti-freeze for the automobile engines?
(b) Propyl alcohol
(c) Ethylene glycol
Ethylene glycol is used as an anti-freeze agent for the automobile engine. In cold countries where temperature is below zero degree centigrade automobile engine cannot used efficiently due to freezing of fuel.
Which one of the following is the correct sequence in increasing order of molecular weights of the hydrocarbons?
(a) Butane, propane, ethane and methane
(b) Propane, butane, ethane and methane
(c) Methane, ethane, propane and butane
(d) Butane , ethane, propane, and methane
‘Yellow cake’, an item of smuggling across border is-
(a) a crude form of heroin
(b) uranium oxide
(c) a crude form of cocaine
(d) unrefined gold
Uranium oxide smuggled across border as yellow cake. Enriched uranium can be used in making illegal nuclear explosive that is dangerous to humanity.
The Chemical used as a ‘fixer’ in photography is-
(a) Ammonium persulphate
(b) Sodium sulphate
(c) Sodium thiosulphate
Sodium thiosulphate is used as a fixer in photography. It removes Ag fromnegative by formating complex with it.