Practical chemistry practice · Mixed difficulty

A metal salt solution forms a yellow ppt with potassium chromate in acetic acid, a white ppt with dilute sulphuric acid, but gives no ppt with sodium chloride or iodide, it is:

During the preparation of acetanilide from aniline. The excess of acetic anhydride and prolongated heating should be avoided because

The group reagent for group $\mathrm{V}$ radicals is

When a mixture of solid ${NaCl},$ solid ${K}_2 {Cr}_2 {O}_7$ is heated with conc. ${H}_2 {SO}_4,$ orange red vapours are obtained. These are of the compound:

If the heat of dissolution of ahydrous $\mathrm{CuSO}_4$ and $\mathrm{CuSO}_4 .5 \mathrm{H}_2 \mathrm{O}$ is $-15.89 \mathrm{~kcal}$ and $2.80 \mathrm{~kcal},$ respectively, then the heat of hydration of $\mathrm{CuSO}_4$ to form $\mathrm{CuSO}_4 \cdot 5 \mathrm{H}_2 \mathrm{O}$ is

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.

Which of the following cations does not import colour to the flame in flame test?

Which of the following is the best scientific method to test the presence of water in a liquid

Phenolphthalein does not act as an indicator for the titration between

Methyl orange gives red colour in

Given that the $K_a\text{(methyl orange)}=4.0 \times 10^{-4},$ a solution at $\mathrm{p H}=2$ containing the indicator would be

Which of the following will be precipitated when dil. $HCl$ is added to their solution.

Sometimes yellow turbidity appears while passing $\mathrm{H}_2 \mathrm{S}$ gas even in the absence of II group radicals. This is because of

A substance on treatment with dil. $\mathrm{H}_2 \mathrm{SO}_4$ liberates a colourless gas which produces (i) turbidity with baryta water and (ii) turns acidified dichromate solution green. The reaction indicates the presence of

In the borax bead test of $\mathrm{Co}^{2+},$ the blue colour of bead is due to the formation of:

Given below are two statements one is labelled as Assertion (A) and the other is labeilled as Reason.

Assertion (A): In the titration of HCl against NaOH, phenolphthalein is used as suitable indicator.

Reason (R): Phenolphthalein is pink coloured in basic medium.

In the light of above statements, choose the most appropriate answer from the options given below.

An acid type indicator, $\text{HIn}$ differs in colour from its conjugate base $\left(\mathrm{In}^{-}\right).$ The human eye is sensitive to colour differences only when the ratio $\frac{\left[\mathrm{In}^{-1}\right]}{[\mathrm{HIn}]}$ is greater than 10 or smaller than 0.1 what should be the minimum change in the $\mathrm{pH}$ of the solution to observe a complete colour change $\left(K_a=1 \times 10^{-5}\right)$

Which of the following nitrogen containing compound does not give Lassaigne's test?

An equimolar mixture of ferrous oxalate & stannous chloride is treated with decinormal acidic $\mathrm{KMnO}_4$ giving ferric, stannic & chlorate ions along with $\mathrm{CO}_2$ gas. If the titre value is $225 \mathrm{~ml}.$ Numbers of millimoles of chlorate ions produced are

The aqueous solution of which salt is coloured

For the indicator the ratio $\frac{\left[I n d^{\ominus}\right]}{[H I n]}$ is 7.0 at $\mathrm{pH}$ of $4.3 K_a$ for the indicator is

In Carius method for the estimation of sulphur precipitate is formed due to the formation of

Select the incorrect statement regarding analytical balance.

When a liquid is delivered from a volumetric
pipet a small amount is typically retained in
the tip. How should a student proceed in
order to deliver the volume of liquid stated
on the pipet?

When $\mathrm{H}_2 \mathrm{S}$ is passed through II group sometimes solution becomes milky. It indicates the presence of

Given below are two statements.

Statement (I) : The gas liberated on warming a salt with dil $\mathrm{H}_2 \mathrm{SO}_4,$ turns a piece of paper dipped in lead acetate into black, it is a confirmatory test for sulphide ion.

Statement (II) : In statement-I the colour of paper turns black because of formation of lead sulphite.

In the light of the above statements, choose the most appropriate answer from the options given below

While preparing crystals of Mohr's salt, dil. $\mathrm{H}_2 \mathrm{SO}_4$ is added to a mixture of ferrous sulphate and ammonium sulphate, before dissolving this mixture in water, dil. $\mathrm{H}_2 \mathrm{SO}_4$ is added here to:

Which is soluble in $\mathrm{NH}_4 \mathrm{OH}?$

When adding the acid from the burette into the conical flask
(i) the acid is initially added drop by drop
(ii) the conical flask is swirled while adding the acid
(iii) the conical flask is placed over a white tile or white sheet of paper
(iv) the inside of the conical flask is washed down from time to time with deionised water.
Which of the above procedures is/are not carried out during the titration?

Beilstein test used for