AB ab2 A,B A2B3 Mass of A (in g) 2 2 4 415 Mass of B (in g) 5 10 5 According to the law of multiple proportions, Masses of B combines with a constant mass of A are 10g, 20g, 5g, 15g Simple...
Assertion (A): Combustion of 16 g of methane gives 18 g of water. Reason (R): In the combustion of methane, water is one of the products. (i) Both A and R are true but R is not the correct explanation of A. (ii) A is true but R is false. (iii) A is false but R is true. (iv) Both A and R are false.
Correct Answer: (iii) A is false but R is true Explanation: Combustion of 16 g of methane gives 36 g of water.
Assertion (A): Significant figures for 0.200 is 3 whereas for 200 it is 1. Reason (R): Zero at the end or right of a number are significantly provided they are not on the right side of the decimal point. (i) Both A and R are true and R is the correct explanation of A. (ii) Both A and R are true but R is not a correct explanation of A. (iii) A is true but R is false. (iv) Both A and R are false.
Correct Answer: (iii) A is true but R is false Explanation: Zero at the end of a number without the decimal point is not significantly based on the rate of accuracy.
The reactant which is entirely consumed in the reaction is known as limiting reagent. In the reaction 2A + 4B → 3C + 4D, when 5 moles of A react with 6 moles of B, then (i) which is the limiting reagent? (ii) calculate the amount of C formed?
(i) The reactant B is the the limiting reagent. (ii) Calculation: Let us consider that the reactant B got completely consumed as it is the limiting reagent. 4 mol of B gives 3 mol of C 6 mol of B...
The density of 3 molal solutions of NaOH is 1.110 g mL–1. Calculate the molarity of the solution.
Calculation: 3 molal solution of NaOH = 3 moles of NaOH dissolved in water 3 mole of NaOH = 120g Density of solution = 1.110gmL-1 Volume = mass/density Volume = 1120g/1.110gmL-1 Volume =1.009L...
Calculate the average atomic mass of hydrogen using the following data :
Isotope % Natural abundance Molar mass 1H 99.985 1 2H 0.015 2 Calculation: Average atomic mass of Hydrogen \[=099.985\times 1+\frac{0.015\times 2}{100}\] ...
45.4 L of dinitrogen reacted with 22.7 L of dioxygen and 45.4 L of nitrous oxide was formed. The reaction is given below:
2N2(g) + O2(g) → 2N2O(g) Which law is being obeyed in this experiment? Write the statement of the law? Answer: The Gay-Lussac’s law is used in the given reaction. The Gay-Lussac’s law states...
Which of the following terms is unitless?
(i) Molality (ii) Molarity (iii) Mole fraction (iv) Mass per cent Answer: Correct Answers: (iii) Mole fraction; (iv) Mass per cent Explanation: Unit of Molality - Molal or moles per kg Unit...
16 g of oxygen has the same number of molecules as in
(i) 16 g of CO (ii) 28 g of N2 (iii) 14 g of N2 (iv) 1.0 g of H2 Answer: Correct Answers: (iii) 14 g of N2; (iv) 1.0 g of H2 Explanation: The no. of molecules in N2 is 0.5 × 6.023 × 1023 The...
What will be the molality of the solution containing 18.25 g of HCl gas in 500 g of water? (i) 0.1 m (ii) 1 M (iii) 0.5 m (iv) 1 m
Correct Answer: (iv) 1 m Explanation: According to molality of a substance which is the number of mass of solute per mass of the solvent in liters, the molality of the solution containing 18.25 g of...
If the concentration of glucose (C6H12O6) in the blood is 0.9 g L-1, what will be the molarity of glucose in the blood? (i) 5 M (ii) 50 M (iii) 0.005 M (iv) 0.5 M
Correct Answer: (iii) 0.005 M Explanation: According to the molarity of a substance which is defined as the number of moles per volume of the solution in litres, the molarity of the glucose in blood...
The number of atoms present in one mole of an element is equal to Avogadro number. Which of the following element contains the greatest number of atoms? (i) 4g He (ii) 46g Na (iii) 0.40g Ca (iv) 12g He
Correct Answer: (iv) 12g He Explanation: The number of atoms present in 4g of Helium – 1 NA The number of atoms present in 46g of Sodium - 2 NA The number of atoms present in 0.04g of Calcium – 0.01...
If 500 mL of a 5M solution is diluted to 1500 mL, what will be the molarity of the solution obtained? (i) 1.5 M (ii) 1.66 M (iii) 0.017 M (iv) 1.59 M
Correct Answer: (ii) 1.66 M Explanation: According to the Using M1V1= M2V2 formula, the value of M2 is 1.66 M.
What will be the molarity of a solution, which contains 5.85 g of NaCl(s) per 500 mL? (i) 4 mol L-1 (ii) 20 molL-1 (iii) 0.2 molL-1 (iv) 2molL-1
Correct Answer: (iii) 0.2 molL-1 Explanation: The Molarity is defined as the number of moles per volume of the solution in litres. Given, Mass = 5.85g Molar mass = 58.5 g/mol Volume of the solution...
A measured temperature on the Fahrenheit scale is 200 °F. What will this reading be on a Celsius scale? (i) 40 °C (ii) 94 °C (iii) 93.3 °C (iv) 30 °C
Correct Answer: (iii) 93.3 °C Explanation: According to the relationship between the temperature in Fahrenheit and Celsius scale, the temperature on Celsius scale is 93.3 °C.
Two students performed the same experiment separately and each one of them recorded two readings of mass which are given below. The correct reading of mass is 3.0 g. Based on given data, mark the correct option out of the following statements. Student Readings
(i) (ii) A 3.01 2.99 B 3.05 2.95 (i) Results of both the students are neither accurate nor precise. (ii) Results of student A are both precise and accurate. (iii) Results of student B are neither...