Chemistry Unit 5 Study Guide

1. ChemistryUnit 5 Study Guide You may use this study guide to review for your test; practice your new skills or review old concepts. Each topic has several questions relating to it, this should help with giving you plenty of practice.

3. Ions and Charges Question A All elements are trying to achieve what electron configuration? A noble gas configuration

4. Ions and Charges Question B The element Sodium is likely to form an ion of what charge and why? +1 because it will give away it’s 1 valence electron to achieve a structure like Ne.

5. Ions and Charges Question C What charge will the element O be likely to form and why? -2 because it will want to take 2 electrons to form a full outside shell like the element Ne.

6. Valence Structure A Given the electron configuration 1s22s22p3; what element is this and what ion charge will it likely have? Element Nitrogen, -3 charge on the ion

7. Valence Structure B An element has an electron configuration of 1s22s22p5, what electron configuration will it try to form and why? 1s22s22p6; in order that it have a full outside electron shell like a noble gas.

8. Valence Structure C How many valence electrons does the following element have? 1s22s22p63s23p2 4

9. Formulas A What would be the formula for Calcium bonding with Iodine? CaI2

10. Formulas B What would be the formula for Cesium bonding with Phosphorus? Cs3P

11. Formulas C What would be the formula for Carbon bonding with Hydrogen? CH4

12. Ionization Energy A What does ionization energy tell us? What is an example of an element with low Ionization energy? Ionization energy tells us how easily and element will give away a valence electron. Any group 1 or 2 element has low ionization energy.

13. Ionization Energy B Which elements have very high ionization energies? Group 6A (16) and Group 7A (17) elements.

14. Ionization Energy C What is the relationship between ionization energy and electronegativity? They act like opposites, an element with low ionization energy will have high electronegativity and vice versa.

15. Molecular Shapes A What shape will a molecule of NH3 form? pyramidal

16. Molecular Shapes B What molecular shape will the molecule AlF3 form? Trigonal planer

17. Molecular Shapes C What shape will water form and why? Bent, because there are two sets of lone pairs that push the bonds down closer together.

18. Polar/NonpolarA Is water a polar or non polar molecule and why? It is polar because the oxygen has a slightly negative charge and the hydrogen a slightly positive due to electronegativities and it’s shape.

19. Polar/NonpolarB Is CH4 polar or non polar and why? Nonpolar, because with it’s tetrahedral shape the slightly positive H surround the C and there is no negative and positive end.

20. Polar/NonpolarC Is the molecule NH3 polar or nonpolar and what is the difference between it and AlF3? Ammonia is polar and is different from AlF3 because AlF3 is trigonal planer and the slightly negative charges surround the positive and so there is no + or – end.

21. Ionic Bonds A How is an ionic bond formed? An atom forfeits it’s electrons due to low electronegativity to an atom that has high electronegativity and since the two ions have opposite charges they are drawn together to neutralize the charge.

22. Ionic Bonds B If there is an ion with a charge of -2; name two ways that it’s charge could be neutralized in a bond. It could bond with an ion with a +2 charge or 2 ions with a +1 charge.

23. Ionic Bonds C What do we call a negative ion? A positive ion? Anion; cation

24. Covalent Bonds A How is a covalent bond different from an ionic? An ionic bond consists of exchange of electrons forming ions, in a covalent bond the electrons are shared between the atom’s electron shells.

25. Covalent Bonds B What types of elements make up a covalent bond? 2 non metals joined together or in other words elements from groups 4A,5A and 6A.

26. Covalent Bonds C Which is stronger an ionic bond or a covalent bond? Ionic bond because of the electromagnetic force holding the atoms tightly.

27. StoichiometryA If you are given 17 grams of C how many grams of water would you need to react with that? C + H2O → CO + H2 25.5 g of water

28. StoichiometryB If you had 8 L of H2, how many L of O2 would you need to react? 2H2 + O2→2H2O 4L of O2

29. StoichiometryC If you have 12.04 x 1023 molecules of H2O you have how many grams is that? 32 grams water

30. Balancing Equations A Balance the equation below: C3H8 + O2→CO2 + H2O 1:5:3:4

31. Balancing Equations B Why do we balance equations? So that the law of conservation of mass is satisfied and we can obtain the molar ratio of reactants and products.

32. Balancing Equations C Balance the equation below: HCl + Mg(NO3)2→ HNO3 + MgCl2 2:1:2:1

33. ElectronegativityA What is electronegativity and what causes it to increase or decrease? The ability of an atom to pull electrons from another atom and add them to its outside shell. The size of the atom affects it as well as the number of valence electrons. The smaller the atom the higher the electronegativity and the more valence the higher it is.

34. ElectronegativityB On the metals side of the Periodic Table what happens to the electronegativity values as you go down a group? They decrease

35. ElectronegativityC What is the most electronegative element on the Periodic Table? Fluorine F

36. Formulas with Polyatomic Ions A What is the formula for Cu which has a +1 charge with nitrate? CuNO3

37. Formulas with Polyatomic Ions B What is the formula for Magnesium acetate? Mg(C2H3O2)2

38. Formulas with Polyatomic Ions C What is the formula for calcium combing with a sulfate ion? CaSO4