Chemistry

Free set

Showing 576 to 600 of 1398 questions (page 24 of 56).

576. Dissolving 0.5 mol of a solute in 500 g of solvent gives a molality of

A. 0.5 m B. 5 m C. 0.25 m D. 2 m E. 1 m

577. The mass of sodium hydroxide required to prepare 1 dm3 of a 0.5 mol dm-3 solution is

A. 5 g B. 80 g C. 20 g D. 10 g E. 40 g

578. Colligative properties are used experimentally to determine the

A. colour of a solute B. density of the solvent C. molar mass of a solute D. boiling point of the solvent only E. viscosity of the solution

579. A cell placed in a hypertonic solution will

A. shrink as water leaves it B. divide C. gain solute rapidly D. swell and burst E. remain unchanged

580. Rusting of iron requires the presence of

A. nitrogen B. both oxygen and water C. oxygen only D. carbon dioxide only E. water only

581. Galvanizing protects iron because zinc

A. prevents the entry of nitrogen only B. is a better conductor C. is less reactive than iron D. forms an ionic bond with iron E. is more reactive and corrodes preferentially as a sacrificial metal

582. During electroplating, the article to be plated is made the

A. cathode B. reference electrode C. anode D. salt bridge E. electrolyte

583. According to Faraday's first law, the mass of a substance deposited during electrolysis is proportional to

A. the electrode area B. the voltage applied C. the temperature D. the quantity of charge passed E. the resistance of the cell

584. The standard reduction potential of the zinc electrode is about

A. +0.34 V B. -0.34 V C. 0.00 V D. +0.76 V E. -0.76 V

585. The usual unit of reaction rate is

A. mol dm-3 s-1 B. mol s C. s-1 D. mol dm-3 E. dm3 mol-1

586. According to collision theory, a collision leads to reaction only if the molecules have sufficient energy and

A. a catalyst present B. equal masses C. the same charge D. identical speeds E. the correct orientation

587. A reaction initiated by the absorption of light is called

A. a chain terminating reaction B. an electrochemical reaction C. a photochemical reaction D. a thermal reaction E. an autocatalytic reaction

588. For a main group element, the number of valence electrons is indicated by its

A. atomic mass B. period number C. group number D. oxidation state only E. atomic radius

589. The second ionization energy of an element is always greater than the first because

A. the atom becomes larger B. the nuclear charge decreases C. the electron is closer to the nucleus in the neutral atom D. shielding increases E. an electron is removed from a positively charged ion

590. Across a period, the character of the oxides changes from

A. unchanged B. basic to neutral only C. acidic to neutral only D. basic through amphoteric to acidic E. acidic through amphoteric to basic

591. The transition elements occupy the

A. s block B. d block C. f block D. p block E. noble gas group

592. The chemical inertness of the noble gases is due to their

A. completely filled valence shells B. large size C. radioactivity D. low atomic mass E. high density

593. The hydrides of the alkali metals are

A. covalent and volatile B. ionic solids containing the hydride ion C. non-existent D. metallic E. polymeric

594. Permanent hardness of water is caused mainly by dissolved

A. calcium and magnesium sulphates and chlorides B. potassium nitrate C. sodium chloride D. dissolved carbon dioxide E. calcium and magnesium bicarbonates

595. Caustic soda is the common name for

A. sodium bicarbonate B. calcium hydroxide C. sodium chloride D. sodium hydroxide E. sodium carbonate

596. Graphite conducts electricity because

A. its atoms are sp3 hybridized B. it contains free protons C. each carbon has one delocalized electron in a layer structure D. it has ionic bonds E. it is amorphous

597. Ammonia is manufactured industrially by the

A. Solvay process B. Haber process C. Bosch process D. contact process E. Ostwald process

598. Sulphur dioxide acts as a bleaching agent by

A. reduction B. adsorption only C. precipitation D. hydrolysis E. oxidation

599. Anhydrous copper sulphate is white while the pentahydrate is blue because the colour arises from

A. water molecules coordinated to the copper ion B. hydrogen bonding alone C. the crystal shape D. impurities E. the sulphate ion

600. The catalyst used in a vehicle catalytic converter is mainly

A. vanadium pentoxide B. nickel C. platinum and rhodium D. aluminium chloride E. iron

Previous 1 2 … 22 23 24 25 26 … 55 56 Next

Get full access to the MCQ bank

Premium questions, timed mock tests, and detailed explanations.

See premium plans