CBSE Class 11 (Science) Some Basic Concepts of Chemistry — practice questions
80 free MCQs with worked solutions. Tap any question for the answer + explanation, or practice them all in the app.
Practice CBSE Class 11 (Science) Some Basic Concepts of Chemistry in the app →As per your syllabus, Chemistry Ch 1, who proposed the LAW OF CONSERVATION OF MASS in 1789?As per your syllabus, who proposed the LAW OF DEFINITE PROPORTIONS — using natural + synthetic cupric carbonatAs per your syllabus, who proposed the LAW OF MULTIPLE PROPORTIONS in 1803?As per your syllabus, who proposed the LAW OF GASEOUS VOLUMES in 1808?As per your syllabus, who proposed AVOGADRO'S LAW (1811) — that equal volumes of all gases at the same T and PAs per your syllabus, the AVOGADRO CONSTANT (N_A) has the approximate value of which?As per your syllabus, 1 mole of WATER MOLECULES contains how many water molecules?As per your syllabus, what is the MASS PERCENTAGE of oxygen in WATER (H₂O)?As per your syllabus, what mass of WATER is produced by the combustion of 16 g of methane (CH₄)?As per your syllabus, MOLARITY (M) of a solution is defined as which?As per your syllabus, MOLALITY (m) of a solution is defined as which ratio?As per your syllabus, mass % (w/w%) is given by which formula?The molecular mass of water H$_2$O (using H = 1, O = 16) is:One mole of any substance contains:Which state of matter has a definite volume but no definite shape?Which of these is a homogeneous mixture?The components of a mixture can be separated by which methods?The constituent elements of a compound can be separated into simpler substances by which methods?Which of these is a chemical property of a substance?Observing which property of a substance requires a chemical change to occur?Which body maintains the National Standards of Measurement in India?What is the SI unit of the amount of substance?Which SI base unit measures luminous intensity?The kilogram is now defined by fixing the numerical value of which constant?Under the current SI definition, one mole contains exactly how many elementary entities?Which SI prefix stands for a factor of 10^-9?How does the weight of an object differ from its mass?Which of these can change when an object is moved from one place to another?Which instrument is used to determine mass accurately in a laboratory?One cubic decimetre (1 dm^3) is equal to how many cubic centimetres?What is the SI unit of density?A higher density of a substance indicates that its particles are:Which is the SI unit of temperature?A room is at 25 °C. What is this temperature on the kelvin scale?Normal body temperature is 37 °C. What is it on the Fahrenheit scale?On which temperature scale is a negative value impossible?How is 0.00016 written in scientific notation?What is the sum of 3.2 x 10^3 and 4.0 x 10^2?How many significant figures does the value 3.0080 have?How many significant figures are in 6.020 x 10^-3?In measurement, what does the term precision refer to?True mass 5.00 g; a student records 4.81 g and 4.80 g. The readings are:With correct significant figures, the product 3.6 x 1.235 is reported as:Converting units by multiplying with unit factors is also known as:A metal rod is 5 inches long. What is its length in centimetres?Which scientist concluded that matter can neither be created nor destroyed?Which chemist gave the law of definite proportions?Proust compared natural and synthetic samples of which compound?Oxygen masses joined to a fixed mass of hydrogen in water and in hydrogen peroxide are in what ratio?12 g of carbon joins 16 g of oxygen in CO and 32 g in CO2. Which law does this show?In which year did Gay Lussac give his law of gaseous volumes?At the same temperature and pressure, 300 mL of hydrogen combines with how much oxygen to form water vapour?Equal volumes of all gases at the same temperature and pressure contain equal:At the 1860 international chemistry conference, who stressed the importance of Avogadro's work?Which law could Dalton's atomic theory not explain?Which statement is a postulate of Dalton's atomic theory?Which isotope is the present standard for atomic masses?One atomic mass unit is defined as exactly:Chlorine is 75.77% Cl-35 (34.97 u) and 24.23% Cl-37 (36.97 u). Its average atomic mass is about:The atomic mass values normally quoted for elements are:Allowing for its isotopes, the average atomic mass of carbon is about:For which substance is formula mass used instead of molecular mass?In a sodium chloride crystal, each Na+ ion is surrounded by how many Cl- ions?Taking C = 12.01 u and O = 16.00 u, what is the molecular mass of CO2?Using Ca = 40, C = 12 and O = 16, what is the formula mass of calcium carbonate, CaCO3?What is the mass of one mole of a substance, expressed in grams, called?How many moles of hydrogen atoms are present in 2 mol of propane, C3H8?The molar mass of a substance in grams is numerically equal to its:What is the mass per cent of carbon in CO2 (C = 12.01, molar mass 44.01 g/mol)?What does an empirical formula of a compound represent?A compound is 40.0% C, 6.7% H and 53.3% O by mass. What is its empirical formula?How much water forms when 8 g of methane burns completely (CH4 + 2O2 gives CO2 + 2H2O)?The reactant that is used up first and limits the product formed is called the:For N2 + 3H2 giving 2NH3, how much ammonia forms from 2 mol of N2 and 3 mol of H2?In the balanced equation 2C4H10 + xO2 giving 8CO2 + 10H2O, what is x?What must never be changed when balancing a chemical equation?Molarity is the number of moles of solute present in one:A concentrated solution that is diluted to prepare weaker solutions is called a:Which of these drugs is used in cancer therapy?Pure substances are further classified into which two groups?