Iron II Oxide

Q. Blood red coloured solution is produced when ferric chloride solution is treated with:

1. $KSCN$
2. $KOH$
3. $K_4\left[Fe\right(CN{)}_6]$
4. $K_3\left[Fe\right(CN{)}_6]$

Q. When a metal rod $M$ is dipped into an aqueous colourless concentrated solution of $AgN{O}_3$, the solution turns light blue. Addition of aqueous $NaCl$ to the blue solution gives a white precipitate O. Addition of aqueous $N{H}_3$ dissolves $O$ and gives an intense blue solution.
The metal rod $M$ is

1. $Fe$
2. $Cu$
3. $Ni$
4. $Co$

Q.

Simplify the following mathematical expressions:

$42-[20-\{19-(14-8-4)\left\}\right]$

Q. The coloured solution $S$ contains

1. $F{e}_2(S{O}_4{)}_3$
2. $ZnS{O}_4$
3. $N{a}_{2}Cr{O}_4$
4. $CuS{O}_4$

Q. Which of the following is not a preliminary test for detecting anions?

1. Borax bead test
2. Flame test
3. Brown ring test
4. Cobalt nitrate test

Q. What is false about Mohr salt

1. It’s a primary standard
2. double salt
3. It decoloures $KMn{O}_4$
4. Oxidation state of iron is +3 in salt

Q. A solution containing cupric ions is allowed to react with potassium iodide. Select the incorrect option.

1. The hypo solution convert the triiodide ions to iodide ions
   
2. The colour the precipitate obtained becomes visible if hypo solution is added
3. White coloured precipitate of cupric iodide is obtained
4. The solution is intensely brown in colour to formation of triiodide ions

Q. Iron is rendered passive by treatment with concentrated

1. $H_{3}P{O}_4$
2. HCl
3. $HN{O}_3$
4. $H_{2}S{O}_4$

Q. $N{H}_{4}SCN$ can be used to test one or more out of $F{e}^{3+}$, $C{o}^{2+}$, $C{u}^{2+}$

1. $F{e}^{3+}$ only
2. $C{o}^{2+}$, $C{u}^{2+}$
3. all of these
4. $F{e}^{3+}$, $C{u}^{2+}$

Q. Ion present in the Nessler's reagent is:

1. $H{g}^{+}$
2. $H{g}^{+2}$
3. ${\left[Hg\right(N{H}_3{)}_4]}^{+2}$
4. ${\left[Hg{I}_4\right]}^{-2}$

Q. Which of the following ions is formed when an aqueous solution of ammonia is added to the $\left[Cu\right(H_{2}O{)}_6{]}^{2+}$?

1. $\left[Cu\right(H_{2}O{)}_2(N{H}_3{)}_4{]}^{2+}$
2. $\left[Cu\right(H_{2}O{)}_3(N{H}_3{)}_3{]}^{2+}$
3. $\left[Cu\right(H_{2}O{)}_4(N{H}_3{)}_2{]}^{2+}$
4. $\left[Cu\right(H_{2}O{)}_1(N{H}_3{)}_5{]}^{2+}$

Q. Iron is rendered passive by treatment with concentrated:

1. $H_{2}S{O}_4$
2. $HCl$
3. $H_{3}P{O}_4$
4. $HN{O}_3$

Q. Colour of solution of compound $M$ is

1. Black
2. Green
3. Yellow
4. Orange