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The compound [Cu(NH\(_3\))\(_4\)]Cl\(_2\) is an ionic compound composed of a complex cation, the tetraamminecopper(II) ion ([Cu(NH\(_3\))\(_4\)]\(^{2+}\)), and two chloride anions (Cl\(^−\)). The primary force connecting the positively charged complex ion and the negatively charged chloride ions is the electrostatic attraction known as an ionic bond. This bond forms between species with a significant difference in electronegativity, specifically between a cation and an anion. Dative bonds (coordinate covalent bonds) exist within the complex ion itself, specifically between the central copper(II) ion and the nitrogen atoms of the ammonia ligands. Van der Waals forces and typical covalent bonds are not the main attractive forces between the distinct cation and anion units in this solid salt structure. The correct answer is ionic - option C

The commercial deodorant (specifically spray or mist form) is an example of a colloid called an aerosol. In this type of colloid, the dispersed phase (the substance being spread out) is a liquid, while the dispersion medium (the substance the phase is dispersed in) is a gas (air or propellant).

In the reaction given, the chemical reaction can be re-written as A + B → C + D This implies, A and B are the reactants, while C and D are the products. The energy level of the products (C+D) is higher (50) on the graph than the energy level of the reactants (A+B), (20). The arrow representing the overall enthalpy change (\DeltaH) points upward, showing a gain in energy, resulting in a positive \DeltaH value. i.e \DeltaH\(_{reaction}\) = \DeltaH\(_{product}\) - \DeltaH\(_{reactant}\) \DeltaH\(_{reaction}\) = (C+D) - ( A+B) = 50 - 20 = +30 \DeltaH\(_{reaction}\) = + ve , hence, it is an endothermic reaction - option B

Answer: A. Red (Visible spectrum: red ~700 nm, longest; violet ~400 nm, shortest.)

Lens power P = 1/f, where f is focal length in meters; unit is diopter.

The two displacements are 6.0 m East and 10.0 m at N30ºE. The angle between East and N30ºE is 60^\circ. Using the cosine rule: R\(^2\) = 6\(^2\) +10\(^2\) +2(6)(10)cos60º R\(^2\) = 36 + 100 +120 (0.5) = 196 R = \(\sqrt{196}\) = 14.0m

Answer: D. 10cm³ (Volume ice = \(\frac{90}{0.9}\) = 100 cm\(^3\); volume water = \(\frac{90}{1}\) = 90 cm\(^3\); change = 10 cm\(^3\) decrease.)

Answer: D. thermodynamic (Pressure law P ∝ T requires an absolute scale like Kelvin (thermodynamic) for a line through the origin at T= 0, P= 0. Rankine is also absolute but less common in this context.)

D. Rate of change of momentum imparted to the walls per second per unit area. (Pressure = force/area = (rate of momentum change)/area from molecular collisions.)

Answer: D. It is longitudinal (String waves are transverse; perpendicular to propagation.

Answer: C. open circuit (EMF is maximum PD with no current drawn.

Answer: B. volume with temperature (Mercury thermometers rely on thermal expansion of volume.)

Answer: A. cornea and lens (Main refractive structures.)

Answer: B. 5N (F ∝ \(\frac{1}{r^2}\); doubled r → \(\frac{\text{F}}{4}\) = \(\frac{20}{4}\) = 5 N.)

Answer: C. 30^\circC (Volume exp. γ = 3 \alpha = 6\times10\(^{-5}\)K\(^{-1}\); \DeltaV = V γ \theta; \theta = \(\frac{0.0018}{1 \times 6\times 10^{-5}}\) = 30^\circC.