Zadanie 1c
The final step can be summarized as: 3 NO2(g) + H2O(l) → 2 HNO3(aq) + NO(g) ΔH⊖ = −138 kJ mol−1 (i) Sketch an energy profile for the overall reaction, indicating ΔH⊖ and the activation energy. (ii) Describe the…
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Covalent bonds and Lewis formulas
Describe the covalent bond as attraction between a shared electron pair and the nuclei, and draw Lewis formulas for molecules and ions with up to four electron pairs per atom, including species with incomplete octets such as BF3.
Tę umiejętność sprawdza 21 zadań wzorowanych na arkuszach IB z lat 2022–2026.
Zadania sprawdzające tę umiejętność: 21 Otwórz w wyszukiwarce z filtrami
Zadanie 2c
(i) Write the equation for the reaction of Rb with water, H2O, including state symbols. (ii) Describe the type of bonding in Rb and in H2O, and explain how the valence electrons in each produce that type of bond.
Zadanie 9
Which electrostatic attraction holds the two atoms together in a molecule of hydrogen, H2? A. Between the two nuclei B. Between the two electrons of the shared pair C. Between neighbouring hydrogen molecules D. Between each nucleus and the shared pair…
Zadanie 1a
At room temperature hydrogen cyanide is a liquid that evaporates readily, whereas ethyne, C2H2, which has almost the same molar mass, is a gas that boils at −84 °C. (i) Draw the Lewis formula of the hydrogen cyanide molecule, showing all valence…
Zadanie 5c
(i) Draw the Lewis formula of buta-1,3-diene. (ii) State the hybridization of the carbon atoms in buta-1,3-diene.
Zadanie 6b
Both ionic and covalent bonding are present in sodium ethanedioate, Na2C2O4. (i) Describe both types of chemical bonding present in this compound. Ionic bonding: Covalent bonding: (ii) Deduce a Lewis formula of the ethanedioate ion, C2O42−.…
Zadanie 9
For which of these molecules is the octet rule satisfied by every atom? I. SiCl4 II. NCl3 III. BCl3 A. I and II only B. I and III only C. II and III only D. I, II and III
Zadanie 10a
(i) State the electron configuration of a nitrogen atom. (ii) Draw the Lewis formula of ammonia. (iii) Deduce the electron domain geometry and the molecular geometry of the ammonia molecule. (iv) Explain why the ammonia molecule is polar.
Zadanie 1c
Sulfur forms a dichloride, SCl2, and a hexafluoride, SF6. (i) Deduce the Lewis formula of SCl2. (ii) Deduce the molecular geometry of SCl2 and of SF6. (iii) Suggest a value for the bond angle in SCl2.
Zadanie 3c
A computer simulation models what happens when small pieces of lithium and of sodium are dropped into water. For each metal five pieces of increasing mass are used, the same set of masses for both metals, and the simulation records how long each piece takes to…
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Zadanie 2b
(i) Draw a Lewis (electron dot) structure of the nitrite ion. (ii) Deduce the formal charges of the nitrogen atom and of both oxygen atoms, and add them to the structure you drew in (i). (iii) Predict the shape of the ion and the size of the O-N-O bond angle.…
Zadanie 2c
Suggest a length, in pm, for the nitrogen-oxygen bonds in the nitrite ion and explain your choice. Use section 11 of the data booklet.
Zadanie 12
What is the number of bonding pairs of electrons in propanedioic acid, HOOC−CH2−COOH? A. 8 B. 10 C. 12 D. 20
Zadanie 2b
Ozone, O3, is formed in photochemical smog from oxygen molecules and oxygen atoms. Deduce the Lewis structure of ozone.
Zadanie 5a
(i) Draw one Lewis (electron dot) structure of the sulfate ion. (ii) Calculate the percentage of oxygen present in the double salt. (iii) Determine the empirical formula of the double salt. Use section 7 of the data booklet. (iv) The molar mass of the…
Zadanie 9
Which molecule contains a central atom with fewer than eight electrons in its valence shell? A. NCl3 B. SCl2 C. CS2 D. BeCl2
Zadanie 11
In which species does the central atom have fewer than eight valence electrons? A. AlCl3 B. CCl4 C. NH4+ D. H3O+
Zadanie 5c
Aluminium forms a chloride, AlCl3. (i) Draw the Lewis (electron dot) structure of the AlCl3 molecule. (ii) Outline why the Lewis structure of AlCl3 is an exception to the octet rule.
Zadanie 5c
Aluminium reacts with chlorine to form the chloride AlCl3. (i) Draw a Lewis (electron dot) structure for AlCl3. (ii) Outline in what respect this Lewis structure is unusual.
Zadanie 1g
State the type of bonding in calcium, nitrogen and calcium nitride, and how the valence electrons produce each type of bonding.
Zadanie 6a
Ozone, O3, is an allotrope of oxygen found in the upper atmosphere. (i) Complete the boxes with arrows to show the ground-state electron configuration of an oxygen atom. (ii) Deduce a Lewis (electron dot) structure of O3 in which every atom has…
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