Question

Chemistry (XI+NEET)
Some Basic Concepts of Chemistry
Classwork & Homework
(Classwork)
1. Classify the following substances into elements, compounds and mixtures:
(1) Milk (ii) 22 carat gold
(vi)Steel
(iii) lodized table salt (iv)Diamond
(vii) Brass
(xi) Aerated drinks
(viii) Dry ice
(v) Smoke
(xii) Glucose
(ix) Mercury
(xiii) Petrol
(x) Air
(xiv) Glass (xv) Wood
2.
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? NaHCO3 + CH3COOH CH3COONa + H2O + CO2
3
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.
The following data are obtained when dinitrogen and dioxygen react together to form different
compounds. Show that data is in agreement with law of multiple proportions.
Mass of dinitrogen
Mass of dioxygen
14 g
16 g
(ii)
(iii)
28 g
32 g
(iv)
28 g
80 g
14 g
32g
Three oxides of lead on analysis were found to contain lead as under
(1) 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​

Answer 1

Answer:

Diamond, Mercury :- elements

Glass, brass, dry ice, 22 carat gold, steel, glucose, petrol, wood :- compounds

Milk, iodised table salt, smoke, air, aerated drinks:- mixtures