Chapter 1 – Basic Concepts of Chemistry
Assignment 6
Q.1. Is the law of constant composition true for all types of compounds? Explain why or why not?
Q.2. Which postulate of the Dalton's atomic theory was modified after the discovery of isotopes ?
Q.3. 2.0 g of a metal burnt in oxygen gave 3.2 g of its oxide. 1.42 g of the same metal heated in steam gave 2.27 g of its oxide. Which law is shown by this data?
Q.4. If 6.3 g of NaHCO3 are added to 15.0 g of CH3COOH solution, the residue is found to weigh 18.0 g. What is the mass of CO2 released in the reaction ?
Q.5. Carbon and oxygen are known to form two compounds. The carbon content in one of these compounds is 42.9% while in the other, it is 27.3%. Show that the data are in the agreement with the law of multiple proportions.
Q.6. Phosphorus and chlorine form two compounds. The first compound contains 22.54% by mass of phosphorus and 77.46% by mass of chlorine. In the second compound the percentages are 14.88 for phosphorus and 85.12 for chlorine. Show that these data are consistent with the law of multiple proportions.
Q.7. Three oxides of lead on analysis were found to contain lead as under:
(i) 3.45 g of yellow oxide contains 3.21 g of lead.
(ii) 1.195 g of brown oxide contains 1.035 g of lead.
(iii) 1.77 g of red oxide contains 1.61 g of lead.
Show that these data illustrate law of multiple proportions.
Q.8. Two oxides of a metal contain 27.6% and 30% of oxygen respectively. If the formula of the first compound is M3O4, find the formula of the second compound.
Following 2 questions need to be done by those students who are planning to appear in JEE / NEET.
Q.9. Hydrogen sulphide (H2S) contains 94.11% sulphur, water (H2O) contains 11.11% hydrogen and sulphur dioxide (SO2) contain 50% oxygen. Show that the results are in agreement with law of reciprocal proportions.
Q.10. Water contains 88.90% oxygen and 11.10% of hydrogen, ammonia contains 82.35% of nitrogen and 17.65% of hydrogen and dinitrogen trioxide contains 63.15% oxygen and 36.85% of nitrogen. Show that these data illustrate law of reciprocal proportions.
Online Tuitions & Self-Study Courses for Grade 6 to 12 & JEE / NEET