Class 10 Science Chapter 3 MCQ

Here, all statements are correct. Hence, your answer will be option [D].

CuSO4 + Fe can undergo a chemical reaction. As iron metal is more reactive than copper metal, iron displaces copper from copper sulphate solution and forms aqueous iron sulphate (FeSO4) and solid copper (Cu). This a single displacement reaction also known as a substitution reaction. The iron can be solid or aqueous but the copper sulphate must be aqueous in order to facilitate the reaction.

Bromine, a non-metal, is a liquid. Metals are generally solid whereas non-metals can be solid, liquid and gas. Bromine is a non-metal that exists as liquid.

Silver metal is the best conductor of heat. Copper and Aluminium metals are also very good conductors of heat. Mercury metal is also a poor conductor of heat. The poorest conductor of heat among the metals is lead.

Steel contains non-metal as one of its constituents. Steel is an alloy made by combining iron and other elements mainly carbon. Carbon gives strength to iron. It is used to make buildings, ships, automobiles, machines, appliances.

The metals which have high densities, we mean that metals are heavy substances. For example, the density of iron is 7.8 g/cm3 which is quite high. So, iron metal is a heavy substance. There are, however, some exceptions. For example, sodium and potassium metals have low densities (of 0.97 g/cm3 and 0.86 g/cm3 respectively). They are very light metals.

Non-metals are brittle which means that non-metals break into pieces when hammered or stretched. For example, sulphur and phosphorus are solid non-metals which are non-malleable and non-ductile.

Non-metals have low melting points and boiling points. But diamond is an exception. Diamond is a non-metal which has a very high melting point and boiling point (just like metals).

A solution of sulphur dioxide in water turns blue litmus to red. This shows that sulphur dioxide is acidic in nature.

Here, all the statements are correct. Hence, your answer will be option [D].

Magnesium metal does not react with cold water. Magnesium reacts with hot water to form magnesium hydroxide and hydrogen: You can easily understand by this equation: Mg (s) + 2H2O (l) → Mg(OH)2 (aq) + H2 (g) Magnesium + Water (hot) → Magnesium hydroxide + Hydrogen

Here, all the statements are correct. Hence, your answer will be option [D].

Coating iron or steel with a layer of zinc prevents it from rusting. This process is called galvanization. Water pipes are also galvanized to protect them from corrosion.

Silver articles turn black after prolonged exposure to air due to the reaction of sulphur present in air. Silver reacts with sulphur to form dark grey to black silver sulphide.

Here, all the statements are correct. Hence, your answer will be option [D].

In solid state, ions in ionic compounds are not free to move. Thus, such compounds do not show electrical conductivity in solid state. Whereas, in molten state, ions are free to move and hence conduct electricity.

Here, all the statements are correct. Hence, your answer will be option [D].

Pure gold, known as 24 carat gold, is very soft. It is, therefore, not suitable for making jewellery. It is alloyed with either silver or copper to make it hard. Generally, in India, 22 carat gold is used for making ornaments. It means that 22 parts of pure gold is alloyed with 2 parts of either copper or silver.

Does not give hydrogen gas on reacting with metals. Nitric acid is a strong oxidizing agent. It oxidizes hydrogen produced in the reaction to water and nitric acid itself is reduced to any of these nitrogen oxides [N2O (nitrous oxide), NO (nitric oxide) or NO2 (nitrogen dioxide)]. On the contrary, magnesium and manganese reacts with dilute nitric acid to give salt and hydrogen gas.

Aqua regia, (Latin for ‘royal water’) is a freshly prepared mixture of concentrated hydrochloric acid and concentrated nitric acid in the ratio of 3:1. It can dissolve gold, even though neither of these acids can do so alone. Aqua regia is a highly corrosive, fuming liquid. It is one of the few reagents that is able to dissolve gold and platinum.

Metals like potassium and sodium react violently with cold water. In case of sodium and potassium, the reaction is so violent and exothermic that the evolved hydrogen immediately catches fire. You can easily understand by this equation: 2K(s) + 2H2O(l) → 2KOH(aq) + H2 (g) + heat energy 2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g) + heat energy

Na (sodium) and Ca(calcium) react with water vigorously. Mg (Magnesium) reacts with water less vigorously than that of calcium and sodium. Fe (Iron), on the other hand, does not react with cold as well as hot water instantly. But when the iron is kept in contact with water for a long time, rusting of iron happens.

Copper metal is more reactive than silver metal (Ag), so a displacement reaction will take place between AgNO3 solution and copper metal. In option A: Copper metal is less reactive than sodium metal (Na), so no displacement reaction will occur between NaCl solution and copper metal. In option B: Aluminium metal is less reactive than magnesium metal (Mg), so no displacement reaction will take place between MgCl2 solution and Aluminium metal. In option C: Silver metal is less reactive than iron metal (Fe), so no displacement reaction will occur between FeSO4 solution and silver metal.

The ability of metals to be drawn into thin wire is called ductility. It is one such property of metals that is used to make wires from metals. Metals such as copper have high ductility and thus can be drawn into long and thin wires without breaking.

Metals generally do not show dullness. Metals such as gold and silver usually are shiny rather than dull.