- 1(current)
Q. No.Find the oxidation state of molybdenum in the yellow precipitate (compound X) formed when phosphorus is tested using ammonium molybdate.
1. Six (6)
2. One (1)
3. Seven (7)
4. Eight (8)
1. Six (6)
2. One (1)
3. Seven (7)
4. Eight (8)
Subtopic: Detection of Anions |
61%
Level 2: 60%+
Please attempt this question first.
Hints
Please attempt this question first.
Which of the following statements is incorrect regarding the brown ring test for nitrate ions (NO₃⁻)?
1. A dark brown ring appears at the junction of two solutions.
2. The brown ring is formed due to the formation of a nitrosoferrous sulphate complex.
3. The brown complex has the formula [Fe(H₂O)₅(NO)]SO₄.
4. Heating a nitrate salt with concentrated H₂SO₄ produces light brown fumes.
Subtopic: Detection of Anions |
Level 3: 35%-60%
Please attempt this question first.
Hints
Please attempt this question first.
Match the anion radicals given in List I with the corresponding characteristics in List II and select the correct option given below:
Codes:
1. A-III, B-I, C-II, D-IV
2. A-II, B-I, C-IV, D-III
3. A-IV, B-I, C-III, D-II
4. A-IV, B-I, C-II, D-III
| List-I (Anions) | List-II (Gas evolved on reaction with dil H2SO4) |
||
| A. | \(\mathrm{CO}_3^{2-}\) | I. | Colourless gas that turns lead acetate paper black. |
| B. | \(\mathrm{S}^{2-}\) | II. | Colourless gas that turns acidified potassium dichromate solution green. |
| C. | \(\mathrm{SO}_3^{2-}\) | III. | Brown fumes that turn acidified \(\mathrm{KI}\) solution containing starch blue. |
| D. | \(\mathrm{NO}_2^{-}\) | IV. | Colourless gas evolved with brisk effervescence, which turns lime water milky. |
1. A-III, B-I, C-II, D-IV
2. A-II, B-I, C-IV, D-III
3. A-IV, B-I, C-III, D-II
4. A-IV, B-I, C-II, D-III
Subtopic: Detection of Anions |
79%
Level 2: 60%+
Please attempt this question first.
Hints
A white precipitate was formed when \(\text{BaCl}_2\) was added to water extract of an inorganic salt. Further, a gas 'X' with characteristic odour was released when the formed white precipitate was dissolved in dilute HCl. The anion present in the inorganic salt is:
1. \(\text{I}^-\)
2. \(\text{SO}^{2-}_{3}\)
3. \(\text{S}^{2-}\)
4. \(\text{NO}^{-}_{2}\)
1. \(\text{I}^-\)
2. \(\text{SO}^{2-}_{3}\)
3. \(\text{S}^{2-}\)
4. \(\text{NO}^{-}_{2}\)
Subtopic: Detection of Anions |
60%
Level 2: 60%+
Please attempt this question first.
Hints
Consider the sulphides \(HgS,PbS,CuS, Sb_2S_3,As_2S_3\) and \(CdS.\). Number of these sulphides soluble in \(50\% ~HNO_3\) is :
1. 0
2. 4
3. 2
4. 5
1. 0
2. 4
3. 2
4. 5
Subtopic: Detection of Anions |
54%
Level 3: 35%-60%
Please attempt this question first.
Hints
- 1(current)
Q. No.
© 2026 GoodEd Technologies Pvt. Ltd.