Gas $$$Q$$$ decomposes slowly at room temperature. $$\[ \mathrm{Q}(\mathrm{g}) \rightarrow \mathrm{X}(\mathrm{g})+\mathrm{Z}(\mathrm{g}) \]$$ The Boltzmann distribution curve for gas $$$Q$$$ at room temperature is shown. Which change occurs when a catalyst is added to gas $$$Q$$$ ?

The peak of the curve moves to the right on the diagram.

The number of particles with enough energy to decompose increases.

The kinetic energy of the unreacted particles increases.

The value of $E_{\mathrm{a}}$ decreases, moving the vertical dotted line to the right on the diagram.

Chemistry

IGCSE&ALevel

CAIE

Exam No：9701_s24_qp_12 Year：2024 Question No：15

Answer:

3.5.1.1 $\mathrm{BF}_{3} \text { (trigonal planar, } 120^{\circ} \text { ) }$

3.5.1.2 $\left.\mathrm{CO}_{2} \text { (linear, } 180^{\circ}\right)$

3.5.1.3 $\mathrm{CH}_{4} \text { (tetrahedral, 109.5°) }$

3.5.1.4 $\mathrm{NH}_{3} \text { (pyramidal, 107°) }$

3.5.1.5 $\mathrm{H}_{2} \mathrm{O} \text { (non-linear, } 104.5^{\circ})$

3.5.1.6 $\mathrm{SF}_{6} \text { (octahedral, 90°) }$

3.5.1.7 $\mathrm{SF}_{6} \text { (octahedral, 90°) }$

3.5.2 predict the shapes of, and bond angles in, molecules and ions analogous to those specified in 3.5.1