Chemistry Test - 24

A liquid that scatters a beam of light, but leaves no residue when passed through filter paper is a/ancolloidal solution.

Such a large difference in electronegativity shows that Caesium is electropositive while Fluorine is electronegative in nature. So, Caesium can donate an electron to Caesium which can accept it. So, they form ionic bond or electrovalent bond.

Hydrogen peroxide is thermodynamically unstable and decomposes to form water and oxygen.

\(H _{2}{ }\stackrel{1-} O _{2} \rightarrow H _{2}\stackrel{2-}O+\frac{1}{2} \stackrel{0}{ O }_{2}\)

So, both Assertion and Reason are correct and Reason is the correct explanation for Assertion.

The filament resistance of the bulb is greater than its resistance when it is not glowing.

When the bulb is glowing, heat generates. Because of heat resistance of the filament increases. That is why the filament resistance of a glowing bulb is greater than its resistance when it is not glowing.

In a reaction, if reaction quotient is less than the equilibrium constant, the reaction quotient will tend to increase and the reaction will proceed in the forward direction till it reaches equilibrium.

When transition elements form coloured salts due to the presence of unpaired electrons\(CuF _2\)will be coloured in solid state.

The complete above reaction is given as follows:

Pauli's exclusion principle:

"No two electrons in an atom can have the same values of all the four quantum numbers." e.g. \(1 \mathrm{s}^{2}\)

For 1^st at electron, \({n}=1,I=0, {m}=0, {s}=+\frac{1}{2}\)

For 2^nd electron, \(n=1, I=0, m=0, s=-\frac{1}{2}\)

For the two electrons in the same orbital, three quantum numbers are the same but the spin quantum numbers are different.

Given that:

The iron oxide has \(69.9 \%\) iron and \(30.1 \%\) dioxygen by mass.

Thus, \(100 \mathrm{~g}\) of iron oxide contains \(69.9 \mathrm{~g}\) iron and \(30.1 \mathrm{~g}\) dioxygen.

The number of moles of iron present in \(100 \mathrm{~g}\) of iron oxide are:

\(=\frac{\text { Mass }}{\text { Atomic mass }} \)

\( =\frac{69.9}{55.8} \)

\(=1.25\)

The number of moles of dioxygen present in \(100 \mathrm{~g}\) of iron oxide are:

\(=\frac{\text { Mass }}{\text { Atomic mass }} \)

\(=\frac{30.1}{32} \)

\(=0.94\)

The ratio of the number of oxygen atoms to the number of iron atoms present in one formula unit of iron oxide is:

\(=\frac{2 \times 0.94}{1.25} \)

\(=1.5: 1 \)

\(=3: 2\)

Therefore, the formula of the iron oxide is \(\mathrm{Fe}_2 \mathrm{O}_3\).

At same temperature and pressure, equal volumes of gases contain the same number ofmolecules.

Avogadro's hypothesis:

• All gases containing equal moles if substance occupy the same volume at the same temperature and pressure.
• Therefore, equal volumes of gases will have an equal number of particles that can be atoms or molecules.