Page 269 - Chemistry ICSE Class X

Study of Compounds–Sulphuric Acid 255
Tests for Sulphuric Acid and Sulphates

Dilute sulphuric acid and the solution of any soluble sulphate contain
2–
2–
sulphate ion (SO ). So, the tests applicable to sulphate ion (SO ) can be
4
4
used both for testing sulphuric acid [H SO (aq)] and the solution of any
2
4
sulphate.
Tests for dilute H SO and solution of any sulphate
2 4 ĐŝĚŝĐ ĐŚĂƌĂĐƚĞƌ ŽĨ ĂŶLJ ƐŽůƵƟŽŶ ĐĂŶ
ƒ With barium chloride solution. To the given solution of sulphuric ďĞ ƚĞƐƚĞĚ ǁŝƚŚ ďůƵĞ ůŝƚŵƵƐ͘ ĐŝĚƐ ƚƵƌŶ
acid or any sulphate, add barium chloride solution. Formation of ďůƵĞ ůŝƚŵƵƐ ƚŽ ƌĞĚ͘
white precipitate [not soluble in HCl(aq) and HNO (aq ? EQPſTOU VJG
3
solution to be sulphuric acid or a solution of any sulphate.
BaCl (aq) + H SO (aq) o BaSO (s)p + 2HCl(aq)
2
4
4
2
barium chloride sulphuric acid barium sulphate
(white precipitate)
BaCl (aq) + Na SO (aq) o BaSO (s)p + 2NaCl(aq)
4
4
2
2
white precipitate
Test for conc. H SO
2 4
ƒ Physical tests
Š Conc. sulphuric acid is colourless, viscous and a heavy liquid.
Š When a drop of conc. sulphuric acid is added to about 5 mL of
water taken in a test tube, it dissolves with the evolution of heat,
i.e., the test tube becomes warm hot.
ƒ Chemical tests
Š With copper metal. Conc. sulphuric acid on heating with copper
turnings gives out sulphur dioxide (SO ).
2
The liberated gas (SO ECP DG KFGPVKſGF D[
2
y its smell — smell of burning sulphur
y YKVJ VJG CEKFKſGF UQNWVKQP QH RQVCUUKWO FKEJTQOCVG ō [GNNQY
solution of potassium dichromate turns green.
Š With sodium chloride. Conc. sulphuric acid when heated with
solid sodium chloride gives hydrogen chloride [HCl(g)]. The
liberated gas
y has a pungent and irritating odour.
y gives thick white fumes with ammonium hydroxide due to the
formation of ammonium chloride.
NH OH(aq) + HCl(g) o NH Cl(s) + H O(l)
4
4
2
white fumes
ASSIGNMENT 1

Manufacture of sulphuric acid, Properties and uses of sulphuric acid, Tests for sulphuric acid and sulphates

ϭ͘ EĂŵĞ ƚŚĞ ƉƌŽĐĞƐƐ ƵƐĞĚ ŶŽǁĂĚĂLJƐ ĨŽƌ ƚŚĞ ŵĂŶƵĨĂĐƚƵƌĞ ŽĨ ƐƵůƉŚƵƌŝĐ ĂĐŝĚ͘
Ϯ͘ tƌŝƚĞ ĐŚĞŵŝĐĂů ĞƋƵĂƟŽŶƐ ĨŽƌ ƚŚĞ ƌĞĂĐƟŽŶƐ ǁŚŝĐŚ ĨŽƌŵ ƚŚĞ ďĂƐŝƐ ŽĨ ƚŚĞ ŽŶƚĂĐƚ ƉƌŽĐĞƐƐ͘
ϯ͘ ŶƐǁĞƌ ƚŚĞ ĨŽůůŽǁŝŶŐ ŝŶ ƌĞůĂƟŽŶ ƚŽ ŽŶƚĂĐƚ ƉƌŽĐĞƐƐ͗
;ĂͿ ƚŚĞ ƌĂǁ ŵĂƚĞƌŝĂů ƵƐĞĚ
;ďͿ ƚŚĞ ĐĂƚĂůLJƐƚ ƵƐĞĚ
;ĐͿ ƚŚĞ ůŝƋƵŝĚ ŝŶ ǁŚŝĐŚ ƐƵůƉŚƵƌ ƚƌŝŽdžŝĚĞ ŝƐ ĂďƐŽƌďĞĚ͘
;ĚͿ ƚŚĞ ŶĂŵĞ ŽĨ ƚŚĞ ƐŽůƵƟŽŶ ŽďƚĂŝŶĞĚ ŝŶ ;ĐͿ͘
;ĞͿ ƚŚĞ ƌĞĂĐƟŽŶ ĐŽŶĚŝƟŽŶƐ͘