0 12345678910111213141516171819202122232425 CBSE Class X – Science Chemistry Exam (Full Syllabus) This test is designed based on NCERT Syllabus for Class 10 Topics of Science – Chemistry Each time random 25 questions will be displaced from the question bank of 500 + Questions So we recommend you to retake the quiz till you have mastered all the questions 1 / 25 Why are oil and fat containing food items fushed with nitrogen while packing? to prevent reduction To prevent rancid to increase oxidation none of these 2 / 25 Identify the reducing agent in the following reactions 4NH3 + 5O2 → 4NO + 6H2O O2 NH3 NO H2O 3 / 25 State the reactions are exothermic or endothermic in nature: Dissolution of ammonium chloride in water exothermic reaction endothermic reaction Both 1 & 2 none of these 4 / 25 On heating blue coloured powder of copper (II) nitrate in a boiling tube, copper oxide (black), oxygen gas and a brown gas X is formed. Identify the brown gas X evolved. X is nitrogen dioxide gas (NO<sub>2</sub>) that has evolved as brown, choking fumes X is copper oxide gas that has evolved as brown, choking fumes X is oxygen gas that has evolved as brown, choking fumes. none of these 5 / 25 One of the following does not happen during a chemical reaction. Breaking of old chemical bonds and formation of new chemical bonds Formation of new substances with entirely diferent properties Atoms of one element change into those of another element to form new products A rearrangement of atoms takes place to form new products It is not atoms but the bonds between these atoms break and form during chemical reactions. Atoms of elements can rearrange but cannot change into other element. It is not atoms but the bonds between these atoms break and form during chemical reactions. Atoms of elements can rearrange but cannot change into other element. 6 / 25 Which of the following gives the exact increasing order of acid strength? Water < acetic acid < hydrochloric acid Water < hydrochloric acid < acetic acid Acetic acid < water < hydrochloric acid Hydrochloric acid < water < acetic acid The increasing order of acid strength is water < acetic acid < hydrochloride acid. Hydrochloride acid is a strong acid and ionises fully in water. The increasing order of acid strength is water < acetic acid < hydrochloride acid. Hydrochloride acid is a strong acid and ionises fully in water. 7 / 25 The chemical formula for plaster of Paris is : CaSO4.2H2O CaSO4.H2O CaSO4. 1/2H2O 2CaSO4.H2O Chemical name of plaster of Paris is calcium sulphate hemihydrate. It is written in this form because two formula units of CaSO4 share one molecule of water. Chemical name of plaster of Paris is calcium sulphate hemihydrate. It is written in this form because two formula units of CaSO4 share one molecule of water. 8 / 25 Antacid are Acidic in nature Basic in nature both none 9 / 25 The source of citric acid is lemon vinegar orange none 10 / 25 The chemical used in manufacture of soaps Na2Co3 NaOH NACo4 Na2OH 11 / 25 Which of the following affirmation about the modern periodic table are inappropriate? The elements in the modern periodic table are arranged on the basis of their decreasing atomic numbers The elements in the modern periodic table are arranged on the basis of their increasing atomic masses. Isotopes are placed in adjoining group(s) in the periodic table. The elements in the modern periodic table are arranged on the basis of their increasing atomic number 1,2 and 3 1 and 2 2 and 3 3 The modern periodic table is a tabular arrangement of elements in increasing order of their atomic number, which is why isotopes are placed at same position. Hence, only ( 3) is true. 12 / 25 Which of the following elements does not lose an electron with ease? Na F Mg Al Flourine has Ǫ electrons in the outermost orbit. Its atom size is the smallest too. Since it is the most electronegative element, it does not lose an electron easily. Flourine has Ǫ electrons in the outermost orbit. Its atom size is the smallest too. Since it is the most electronegative element, it does not lose an electron easily. 13 / 25 Which is not true about the noble gases? They exist in atomic form They are non metallic in nature Xenon is the most reactive. They are radioactive in nature 14 / 25 The valency of an element vary across a period increases Decreases Remains constant increases/decreases 15 / 25 How many metals are present in second period of periodic table? 10 6 8 2 16 / 25 Which of the followings is the major constituent of the liquefied petroleum gas? Methane Ethane Propane Butane The major constituent of the liquefied petroleum gas is butane. The major constituent of the liquefied petroleum gas is butane. 17 / 25 Ethene is saturated hydrocarbon unsaturated hydrocarbon both 1 & 2 none 18 / 25 Saturated hydrocarbons contains double covalent bonds three covalent bonds four covalent bonds single covalent bonds 19 / 25 The molecular formula of the fourth member of alkane series. C5H10 C4H10 C6H10 C7H10 20 / 25 Chemical name of the compound CH3—CH2—CH2—Br 1-Bromo Propane 2-Bromo Propane 3-Bromo Propane 4-Bromo Propane 21 / 25 Generally, metals react with acids to give salt and hydrogen gas. Which of the following acids does not give hydrogen gas on reacting with metals (except Mn and Mg)? H2SO4 HCI HNO2 All of these Nitric acid (HNO3) is a strong oxidizing agent, so it does not give hydrogen gas on reacting with metals (except Mn and Mg). Nitric acid (HNO3) is a strong oxidizing agent, so it does not give hydrogen gas on reacting with metals (except Mn and Mg). 22 / 25 The poorest conductor of heat among metals is Lead Mercury Calcium Sodium Lead readily reacts with the atmosphere.it conducts heat very slowly. Lead readily reacts with the atmosphere.it conducts heat very slowly. 23 / 25 When calcium metal is added to water, the gas evolved does not catch fire but the same gas evolved on adding potassium metal to water catches fire. Due to high exothermic hydrogen evolved immediately catches fre Due to low exothermic hydrogen evolved immediately catches fre Due to high endothermic hydrogen evolved immediately catches fre Due to low endothermic hydrogen evolved immediately catches fre 24 / 25 The Most malleable and ductile metal mercury sodium gold silver 25 / 25 Which metal is less reactive? magnesium calcium both 1 & 2 none of these Your score is 0% Restart quiz