Practical chemistry practice · Mixed difficulty

The principal reason that solid sodium hydroxide is not used as a primary standard for acid-base titrations is that it

When excess of ${SnCl}_2$ is added to a solution of ${HgCl}_2,$ a white ppt turning grey is obtained. The grey colour is due to the formation of

When adding the indicator to the conical flask,
only two or three drops are added because

(i) too much indicator may make it difficult
to see the colour change at the end-point


(ii) the indicator is corrosive, and adding too
much poses a greater risk

(iii) the indicator may be a weak acid or base
and may interfere with the titration result.

Which of the above statements is/are correct?

Which of the following doesn’t give a ppt. with silver nitrate solution.

When ${K}_2 {Cr}_2 {O}_7$ crystals are heated with conc. ${HCl},$ the gas evolved is

Identify the test which is not a part of qualitative analysis?

To a metal nitrate, when $\text{KI}$ solution is added, a black precipitate is produced at first, on adding excess of $\text{KI},$ orange solution is produced. Identify the metal ion.

A $\mathrm{NaOH}$ solution is to be standardized by titrating it against a known mass of potassium hydrogen phthalate. Which procedure will give a molarity of $\mathrm{NaOH}$ that is too low?

Blue borax bead is obtained with

An aqueous solution of colourless metal sulphate $M,$ gives a white ppt. with $\mathrm{NH}_4 \mathrm{OH}.$ This was soluble in excess of $\mathrm{NH}_4 \mathrm{OH}.$ On passing $\mathrm{H}_2 \mathrm{S}$ through this solution a white ppt is formed. The metal $M$ in the salt is

Which method(s) can be used to determine the concentration of $\mathrm{HNO}_3$ in an aqueous solution of nitric acid?

I) titration with a standard base

II) titration with a standard oxidizing agent

III) precipitation with $\mathrm{A g}^+$

......... is formed when potassium iodide is heated with conc. $\mathrm{H}_2 \mathrm{SO}_4$

An aqueous solution of $\mathrm{FeSO}_4 \cdot \mathrm{Al}_2\left(\mathrm{SO}_4\right)_3$ and chrome alum is heated with excess of $\mathrm{Na}_2 \mathrm{O}_2$ and filtered the materials obtained are

Which of the following does not give ${NH}_3$ on heating with $NaOH$ solution?

$100 \mathrm{~ml}$ of $0.1 \mathrm{~M}$ aqueous ferric alum solution is completely reduced with Iron to give Ferrous Ions. The volume of $0.1 \mathrm{~M}$ acidified $\mathrm{KMnO}_4$ solution required for complete reaction with ferrous Ions in the solution will be

When a substance $A$ reacts with water it produces a combustible gas $B$ and a solution of substance $C$ in water. When another substance $D$ reacts with this solution of $C,$ it also produces the same gas $B$ on warming but $D$ can produce gas $B$ on reaction with dilute sulphuric acid at room temperature. $A$ imparts a deep golden yellow colour a smokeless flame to Bunsen burner. $A, B, C$ and $D$ respectively are:

The compound formed in the borax bead test of $\mathrm{Cu}^{2+}$ ion in oxidising flame is:

Phenolphltalein indicator is prepared by
dissolving phenolpthalein in

$[x]+\mathrm{H}_2 \mathrm{SO}_4 \rightarrow[y]$ a colourless gas with irritating smell, $[{y}]+\mathrm{K}_2 \mathrm{Cr}_2 \mathrm{O}_7+\mathrm{H}_2 \mathrm{SO}_4 \rightarrow$ green solution. $[{x}]$ and $[y]$ are

Which one of the following salt give green coloured flame when the salt is tested by Pt wire

On passing a gas, '$X$', through Nessler's regent, a brown precipitate is obtained. The gas '$X$' is

The presence of $\mathrm{NH}_4^{+}$ radical in solution can be detected by

In Carius method of estimation of halogens, 0.5 g of an organic compound gave 0.376 g of AgBr. The percentage of bromine in the compound is (Atomic mass of Ag = 108 u and Br = 80 u)

The metal ion which is precipitated when $\mathrm{H}_2 \mathrm{S}$ is passed with $\mathrm{HCl}.$

The molar mass of an unknown organic liquid $(M \sim 100)$ is determined by placing $5 \mathrm{~mL}$ of the liquid in a weighed $125-\mathrm{mL}$ conical flask fitted with a piece of ${Al}$ foil with a pin hole in it. The flask is heated in a boiling water bath until the liquid evaporates to expel the air and fill the flask with the unknown vapor at atmospheric pressure. After cooling to room temperature the flask and its contents are reweighed. The uncertainty in which piece of apparatus causes the largest percentage error in the molar mass?

Which of the following pairs of cations can not be separated by using $\mathrm{NH}_3$ solution.

In borax bead test, which of the following compound is formed

Which of the following pairs of ions would be expected to form precipitate when dilute solution are mixed?

When acetic acid and potassium ferrocyanide are added to copper salt, the colour of the precipitate is

$MnO_2$ and $H_2SO_4$ added to NaCl, the greenish yellow gas liberated is