Question

. Four samples A, B, C and D change the colour of pH paper or solution to
Green, Reddish-pink, Blue and Orange. Their pH was recorded as 7, 2, 10.5 &
6 respectively. Which of the samples has the highest amount of Hydrogen ion
concentration? Arrange the four samples in the decreasing order of their pH.

Answer 1

Answer:

a) D is neutral, as its pH value is equal to 7 .

b) C is strongly alkaline, as its pH value is 11.

c) B is strongly acidic, as its pH value is equal to 1 .

d) A is weakly acidic, as its pH value is equal to 4 and more than solution B.

e) E is weakly alkaline, as its pH value is equal to 9 and less than C.

pH value of the given solution in increasing order of hydrogen-ion concentration: 11<9<7<4<1

Answer 2

Answer:

(i) a) B

b) C,A,D,B

(ii) Due to moisture in the atmosphere it converted into Gypsum

CaSO4+1½ H2O CaSO4.2H2O

(iii) Making toys/dolls or statues /fixing broken limbs/making decorative

materials.