Chemistry Test - 6

Temporary hardness of water can be removed by heating the water. Liming can soften the water with the use of calcium hydroxide, this chemical causes the calcium and magnesium carbonate to precipitate out as well.

Mercurous chloride is \(H g C l_{2}\)

\(H g C l_{2} \rightleftharpoons H g^{2+}+2 C l^{-}\)

\(\quad\)\(\quad\)\(\quad\)\(\quad\)\(~S\)\(\quad\)\(\quad\)\(\quad\)\(2S\)

\([\frac{K_{s p}(Hg_{2} Cl_{2})}{4}]^{\frac{1}{3}}\)

Mercuric chloride is soluble in ethanol, methanol, acetone, ethyl acetate, and diethyl ester. It is slightly soluble in acetic acid, pyridine, and carbon disulfide. Its solubility in water at 20°C is 69 g/l.

Given,

\(\mathrm{M}_{1} = 5\) molar

\(\mathrm{V}_{1} = 1\) litre

\(\mathrm{V}_{2} = 10\) litre

According to Dilation Formula,

\(\mathrm{M}_{1} \mathrm{~V}_{1}=\mathrm{M}_{2} \mathrm{~V}_{2}\)

\( \Rightarrow \mathrm{M}_{2}=0.5\)

Normality = Molarity \(\times\) Equivalent number

Equivalent number refers to how many ions are acting in the solution, the number of those ions is called the gram equivalent number.

Here, the Equivalent number \(= 2\)

\(\mathrm{N}_{2}=0.5 \times 2=1.0 \) N

Chemicals are added to food for improving their aesthetic, to increase their shelf-life or to add nutritive value. Antioxidants are used for preservation i.e., for increasing the shelf-life of foods. Food colours, flavours and sweeteners simply enhance the appearance and taste of food.

\(\mathrm{C}_{2} \mathrm{H}_{6}\) compound has \(7\) covalent bonds.

The structure of the Ethane molecule is given below.

From the above structure, we can see that the Ethane molecule has \(6~ \mathrm{C}-\mathrm{H}\) covalent bonds and one \(\mathrm{C-C}\) covalent bond. Therefore, on adding the covalent bonds of \(\mathrm{C}-\mathrm{C}\) and \(\mathrm{C}-\mathrm{H}\) covalent bonds, we can say that the Ethane molecule has \(7\) covalent bonds.

​​Homolysis and Heterolysis:

So when the Carbon - Chlorine bond is broken heterolytically, a cation and an anion are formed.

An example is shown below:

There is a general trend that half filled and completely filled orbitals are more stable than incompletely filled orbitals.

\(\mathrm{C u(II)}\) is more stable than \(\mathrm{C u(I)}\) because it has a \(2^{+}\) charge and is smaller than \(\mathrm{C u(I)}\).

The electron density and effective nuclear charge is greater for \(\mathrm{C u(II)}\) and it forms stronger bonds (high hydration energy) and releases more energy and is more stable.

Therefore, \(\mathrm{C u(I I)}\) is more stable than \(\mathrm{C u(I)}\).

In this case, \({ }_{35}^{80} \mathrm{Br}\),

\(\mathrm{Z}=35 \)

\(\mathrm{~A}=80\)

Number of protons \(=\) number of electrons \(= Z = 35\)

Number of neutrons \(= 80 – 35 = 45\)

Minamata disease is a disorder caused by methyl mercury poisoning that was first described in the inhabitants of Minamata Bay, Japan and resulted from their eating fish contaminated with mercury industrial waste.

Polyacrylonitrile is a synthetic polymer with the linear formula (C₃H₃N)_n. Although it is thermoplastic it does not melt under normal conditions, since it degrades before melting at above 300 °C. Almost all Polyacrylonitrileresins are copolymers made from mixtures of monomers, with acrylonitrile as the main component. As it is a non condensation polymer.