CBSE Class X – Science Chemistry Exam (Full Syllabus)

oxidation is the term of the adding oxygen to a compound hence it is the gain of oxygen.

This is an example of two types of reaction: Redox reaction because oxidation (removal of hydrogen) and reduction (addition of hydrogen), both are happening simultaneously._x000D__x000D_Displacement reaction as it involves displacement by oxygen of H atoms from a compound (NH₃) with an other atom.

washing the hands with water will dilute the acid and wash it out. Any remaining acid will be neutralized with sodium hydrogen carbonate (baking soda) as it is a base. This will minimize the effect of damage caused by acid to the skin.

Baking powder is a mixture of sodium hydrogen carbonate and tartaric acid NaHCO₃ + H+ → CO₂ + H₂O + Sodium salt (from tartaric acid) of acid Carbon dioxide (CO₂) produced during reaction can cause bread or cake to rise and makes Baking powder, tartaric acid neutralises the salt and cake does not taste bitter.

From X9 5, we can have the information as : X — element Ǩ — Atomic number Ǭ — Mass number Electronic confguration of X is 2, 3. Group number is found out on the basis of valance electrons. Valence electrons are 3 so group number is 10 + 3 = 13. Period can be found out by knowing the number of shells

Na and K are alkali metals, whereas Mg and Ca are alkaline earth metals. Alkali metals are more electropositive as compared to alkaline earth metals and can easily lose electrons. Out of Na and K, K will easily lose electrons because of its bigger size and less electronic attraction.

Eka-aluminum (later identified as gallium) has a valency of 3. Hence, the oxide would be of the molecular formula E₂O₃. Other options have a different valency of E.

Catenation is the property of self-linking of an element by which an atom combines with the other atoms of the same element to form long chains

As the compound, CH₃CH₂CH=CH₂ contains four carbon atoms and a double bond attached to the first carbon, so the I.U.P.A.C name of CH₃CH₂CH=CH₂ is But-1-ene.

Na (sodium) possesses all the above properties. It is too soft and can be cut with a knife.. It also reacts with water and burns due to the vigorously formation of hydrogen gas.

Test tube C contains chemical mixture called aqua-regia. It is a mixture of concentrated HCl and concentrated HNO3  in the ratio of 3:1. Aqua-regia dissolves gold (Au) and platinum (Pt) in it, while hydrochloric acid and nitric acid do not.