A compound P is taken in a flat bottomed flask as shown in figure. Dilute hydrochloric acid is added drop by drop. A gas Q is evolved which is then passed in a test tube containing R. A solid precipitate S is formed. R is frequently used in white washing. During white washing a layer of R is applied on the wall and it reacts with gas Q (present in air) to produce white shiny layer of S on the wall. P, Q, R and S respectively are :  P Q R S(1) Na2SO4 SO2 Ca(OH)2 CaSO4(2) Na2SO3 O2 Ca(OH)2 CaO(3) Na2CO3 O2 Ca(OH)2 CaCO3(4) Na2CO3 CO2 Ca(OH)2 CaCO31234

When concentrated H2SO4𝐻2𝑆𝑂4 is added to NaCI (s), the gas evolvedA. bleaches damp blue litmus paperB. forms a white preciptate with AgNO3(aq)C. forms a white precipitate with BaCI2(aq)D. turns moist red litmus paper blue

A solution of a substance ‘X’ is used for white washing.(i) Name the substance ‘X’ and write its formula.(ii) Write the reaction of the substance ‘X’ named in (i) above withwater

Take about 1g solid NaCl in a clean anddry test tube and set up the apparatus asshown in Fig. 2.4.n Add some concentrated sulphuric acid tothe test tube.n What do you observe? Is there a gas comingout of the delivery tube?n Test the gas evolved successively with dryand wet blue litmus paper.n In which case does the litmus paper changecolour?n On the basis of the above Activity, what doyou infer about the acidic character of:(i) dry HC

Take about 1g solid NaCl in a clean anddry test tube and set up the apparatus asshown in Fig. 2.4.n Add some concentrated sulphuric acid tothe test tube.n What do you observe? Is there a gas comingout of the delivery tube?n Test the gas evolved successively with dryand wet blue litmus paper.n In which case does the litmus paper changecolour?n On the basis of the above Activity, what doyou infer about the acidic character of:(i) dry HCl gas(ii) HCl solution?

A chemical compound having smell of chlorine is used to remove yellowness of white clothes in laundries.