class 11 chemistry notes

Comments

Post a Comment

Popular posts from this blog

CHEMICAL PROPERTIES OF CARBON FAMILY

CHEMICAL PROPERTIES OF CARBON FAMILY  (1)        Reactivity towards acids : C, Si, Ge unaffected by dilute acid but Sn dissolves in dilute HNO 3   forming Sn(NO 3 ) 2 . Pb dissolves slowly in dilute HCl forming PbCl 2   and quite readily in dilute HNO 3   forming Pb(NO 3 ) 2   and oxides of nitrogen.             Si is oxidised and undergoes fluorination by hot concentrated HF/HNO 3 .             Sn dissolves in several concentrated acids. Pb does not dissolves in concentrated HCl because a surface coating of PbCl 2   is formed. (2)       Reactivity towards alkalies : Carbon is unaffected by alkalies. Si reacts slowly with cold aqueous solution of NaOH and readily with hot NaOH solution giving solution of silicates [SiO 4 ] 4– . Sn and Pb are amphoteric it dissolve...
Read more

Trigonometry Table

Image
Trigonometry The Word 'trigonometry' is derived from the Greek words 'tri' (meaning tree), 'gon' (meaning sides) and 'metron' (meaning measure). In fact trigonometry is the study of relationship between the sides and angle o the triangle. In This chapter, we will study some ration of the sides of a right triangle with respect to its acute angles, called trigonometric ratios of the angle. We will restrict our discussion to acute angle only. However, these ratios can be extended to other angles also. We will also define the trigonometric rations for angles of measure 0 o and 90 o . We will calculate trigonometric ratios for some specific angles and establish some identities involving these rations, called trigonometric identities. Trigonometricration Let us take a right triangle ABC as shown in Here   CAB (or, in brief, angle A) is an acute angle. Note the position of the side BC with respect to angle A. If faces   A. we ca...
Read more

Preparation and properties of Borax

Preparation             Borax occurs naturally as tincal(contains about 55% borax) in certain inland lakes of India, Tibet andCalifornia (U.S.A.).             Borax can also be prepared from certain other minerals such as boracite, colemanite and boranatrocalcite. The minerals are powdered and boiled with sodium carbonate solution.                      Ca 2 B 6 O 11   +   2Na 2 CO 3 ¾ ®     2CaCO 3   +   Na 2 B 4 O 7   +   2NaBO 2             Borax is crystallised from the filtrate. Sodium metaborate, present in the mother liquor, is converted into borax by passing carbon dioxide through it            ...
Read more