Chemistry - Online Test

Q1. An excess of silver nitrate is added to 100ml of a 0.01M solution of pentaaqua chloride chromium(III)chloride. The number of moles of AgCl precipitated would be
Answer : Option B
Explaination / Solution:

The complex is [M(H2O)5 Cl] Cl2

1000 ml of 1M solution of the complex gives 2 moles of Cl ions

1000 ml of 0.01M solution of the complex will give

[100 ml x 0.01M x 2Cl-] / [1000 ml x 1M] = 0.002 moles of C  ions


Q2. The method by which aniline cannot be prepared is
Answer : Option B
Explaination / Solution:
No Explaination.


Q3. An ionic compound AxBy crystallizes in fcc type crystal structure with B ions at the centre of each face and A ion occupying entre of the cube. the correct formula of AxBy is
Answer : Option B
Explaination / Solution:

number of A ions = (Nc/8) = (8/8)=1

number of B ions = (Nf/2) = (6/2) =3


Q4. The correct corresponding order of names of four aldoses with configuration given below Respectively is,
Answer : Option D
Explaination / Solution:
No Explaination.


Q5. A zero order reaction X →Product , with an initial concentration 0.02M has a half life of 10 min. if one starts with concentration 0.04M, then the half life is
Answer : Option C
Explaination / Solution:




Q6. Antiseptics and disinfectants either kill or prevent growth of microorganisms. Identify which of the following statement is not true.
Answer : Option A
Explaination / Solution:
No Explaination.


Q7.

Following solutions were prepared by mixing different volumes of NaOH of HCl different concentrations.

i. 60 mL (M/10) HCl + 40mL (M/10) NaOH

ii. 55 mL (M/10) HCl + 45 mL (M/10) NaOH

iii. 75 mL (M/5) HCl + 25mL (M/5) NaOH

iv. 100 mL (M/10) HCl + 100 mL (M/10) NaOH

pH of which one of them will be equal to 1?
Answer : Option D
Explaination / Solution:

iii) 75 ml M/5 HCl + 25ml M/5 NaOH

No of moles of HCl = 0.2×75×10-3 = 15 × 10-3

No of moles of NaOH = 0.2 × 25 × 10-3 = 5 × 10-3

No of moles of HCl after mixing = 15 × 10-3 - 5 × 10-3

= 10 × 10-3

concentration of HCl = No of moles of HCl / Vol in litre

= 10 ×103 / 100 ×103 = 0.1M

for (iii) solution, pH of 0.1M HCl = -log10(0.1)

= 1.


Q8. Roasting of sulphide ore gives the gas (A).(A) is a colourless gas. Aqueous solution of (A) is acidic. The gas (A) is
Answer : Option C
Explaination / Solution:
No Explaination.


Q9.

Consider the following half cell reactions:

Mn2+ + 2e Mn   Eº = -1.18V

Mn2+ Mn3+ + e-   Eº = -1.51V

The E for the reaction 3Mn2+ Mn+2Mn3+ , and the possibility of the forward reaction are respectively.

Answer : Option B
Explaination / Solution:

Mn2+ + 2e Mn (Eºred) = -1.18V

2[Mn2+ Mn3+ + e- ](Eºox) = −1.51V

3Mn2+ Mn + 2Mn3+        Eºcell?

Eºcell = ( Eºox )+ ( Eºred )

= −1.511.18 and non spontaneous

= −2.69V

Since Eo is –ve ∆G is +ve and the given forward cell reaction is non – spontaneous.


Q10. Boric acid is an acid because its molecule
Answer : Option D
Explaination / Solution:

B(OH)3 + H2O ↔ [B (OH)4 + H+