Acids Bases and Salts Test - 22

All the above salts contain water of crystallisation and their chemical formulae are given below:

Gypsum - CaSO₄.2H₂O   - (2 molecules of water of crystallisation) 

Epsom salt- MgSO₄.7H₂O - (7 molecules of water of crystallisation)

Blue vitriol - CuSO₄.5H₂O - (5 molecules of water of crystallisation)

Glauber's salt - Na₂SO₄.10H₂O - (10 molecules of water of crystallisation)

Hence, the correct option is (D).

Bleaching powder is prepared by passing chlorine gas over dry slaked lime.

$\underset{\mathrm{soaked} \mathrm{lime}}{Ca\left(OH\right)} +C{l}_2\to \underset{\mathrm{bleaching} \mathrm{powder}}{CaOC{l}_{2 }}+H_{2}O$

Hence, the correct option is (B).

Antacids are mild bases, which when given to a person suffering from acidity, neutralizes the effect of excess acid produced in the stomach giving relief.

Milk of magnesia is an example of an antacid which is used to treat indigestion and acidity.

Hence, the correct option is (A).

pH paper is a strip of fine filter paper impregnated with a universal indicator. It has multiple colours over the sheet of paper that gives the exact information about pH of the solution when it is dipped in the solution. Since pH is the negative log of hydrogen ion concentration so we can say that pH paper gives the exact information of hydrogen ion concentration.

A universal indicator is a mixture of several indicators and it shows different colours at different pH. It only gives a rough idea but not exact pH. 

Phenolphthalein and litmus paper are indicators that give only the information of acidic and basic solutions but not about the exact pH.

Hence, the correct option is (C).

Sodium hydrogencarbonate is produced on a large scale by reacting a cold and concentrated solution of sodium chloride with ammonia and carbon dioxide:

$\underset{\text{Sodium chloride}}{NaCl}+\underset{\text{Ammonia}}{N{H}_3}+\underset{\text{Water}}{H_{2}O}+\underset{\text{Carbon dioxide} }{C{O}_2}\to \underset{\text{Sodium hydrogen carbonate}}{NaHC{O}_3}+\underset{\text{Ammonium chloride}}{N{H}_{4}Cl}$

Hence, the correct option is (B).

Distilled water is the purest form of water and it does not contain any acids dissolved in it, so it does not conducts electricity.

Potable water has minute impurities present in it which results in its low conductivity.

Rain water, on combining with CO₂ gas in the atmosphere produces carbonic acid (H₂CO₃ ) which reacts with to form hydrogen ions, and then conducts electricity.

Hence, the correct option is (A).

Phenolphthalein is often used as an indicator of acid-base titrations. For this application, it turns colourless in acidic solutions and pink in basic solutions. Since soap solution is basic in nature so phenolphthalein indicates by changing its colour pink.

Hence, the correct option is (C).

POP is used in chemical laboratories for sealing air gaps in apparatus where air-tight arrangement is required.

Plaster of paris, quick-setting gypsum plaster consisting of a fine white powder (calcium sulfate hemihydrate, CaSO₄.$\frac{1}{2}$ H₂O), which hardens when moistened and allowed to dry. Known since ancient times, plaster of paris is so called because of its preparation from the abundant gypsum found near Paris.

Hence, the correct option is (B).

This is true that alcohols and glucose contain hydrogen ions in them but they do not dissociate to produce hydrogen ions and hence are unable to show acidic behaviour.

Alcohols and glucose do not dissociate to ionize their hydrogen ion. This is proved by the fact that their solution does not conduct electricity.

Hence, the correct option is (C).

On adding concentrated acid to water, a large amount of heat energy is evolved resulting in an exothermic reaction.

When we add water to the acid it gets diluted and the bonds in the medium get broken so it releases or liberates some energy. That’s why this process is called as an exothermic process. 

Hence, the correct option is (D).

Acids react with metal carbonates to form carbon dioxide gas.

$\mathrm{Metal} \mathrm{carbonate}+\mathrm{Acid}\to \mathrm{Salt}+\mathrm{Carbon} \mathrm{dioxide}+\mathrm{Water}$

So, when sodium carbonate reacts with HCl then it will form NaCl salt, water and carbon dioxide (CO₂).

$\underset{\mathrm{Sodium} \mathrm{Carbonate}}{N{a}_{2}C{O}_3(s/aq)}+2HCl\left(aq\right)⟶\underset{\mathrm{Sodium} \mathrm{Chloride}}{2NaCl\left(aq\right)}+H_{2}O\left(l\right)+\underset{\mathrm{Carbon} \mathrm{Dioxide}}{C{O}_2\left(g\right)}$

Hence, the correct option is (B).

NaOH is basic in character and the higher the pH, the stronger is the base.

The solution is treated as neutral when its pH is 7, acidic when pH is less than 7, and basic when pH is greater than 7. Since NaOH is basic in nature so it must have its pH greater than 7.

Hence, the correct option is (B).

Bases react with non-metallic oxides to form salt and water. This reaction is similar to the neutralisation reaction in which acids react with bases to form salt and water. This shows that non-metallic oxides are acidic in nature.

Hence, the correct option is (B).

Lemon constitutes citric acid and is therefore referred under the category of citrus fruits.

Lactic acid is present in the curd which is formed by the activity of lactobacillus bacteria. 

Tartaric acid is present in the tamarind and grapes. 

Formic acid is present in the ant’s sting. 

Hence, the correct option is (C).

Sulfur Dioxide is a gas with the chemical formula SO₂, whereas water is a liquid with the chemical formula H₂O.

When the gas is dissolved in water, it yields an acid called sulfurous acid with chemical formula H₂SO₃ as shown in the chemical equation:

$S{O}_2 + H_{2}O \to H_{2}S{O}_3$

Sulfurous acid is a good reducing agent with a molar mass $82.07\mathrm{g}/\mathrm{mol}$.

Hence, the correct option is (B).