The periodic table
How are the elements in the periodic table arranged?
Increasing order of atomic number
Define oxidation and reduction in terms of electron transfer.
OIL REG
The main element present in organic compounds is....
carbon
Why are elements in the same group (column) of the periodic table said to have similar chemical properties?
since they have the same number of valence electrons
Assign oxidation numbers to each element in the compound H₂SO₄.
H: +1
O: -3
S: +6
What is the difference between a saturated and an unsaturated hydrocarbon?
Saturated (C-C)
Unsaturated (C=C)
Magnesium (Mg) is in Group 2 and Period 3 of the periodic table. Based on its position, predict its atomic number and its likely ion charge.
Z=12
ionic charge = 2+
In the reaction:
Zn+CuSO4→ZnSO4+CuZn + CuSO₄
Identify which substance is oxidized, which is reduced, and the oxidizing and reducing agents.
Zn is oxidized to Zn2+
Cu2+ is reduced to Cu
What is the molecular formula of heptane?
C7H16
Compare the atomic radius of sodium (Na) and chlorine (Cl). Which one is larger, and why?
The atomic radius of sodium (Na) is larger than that of chlorine (Cl).
Sodium has 11 protons while chlorine has 17 protons in its nucleus. The greater positive charge in chlorine pulls the electrons more strongly toward the nucleus.
In a galvanic cell, zinc is placed in a ZnSO₄ solution and copper in a CuSO₄ solution, connected by a salt bridge.
a) Which electrode is the anode and which is the cathode?
b) Determine the direction of electron flow.
Zn is the anode
Cu is the cathode
Electrons flow from Zn to Cu
What are the products of the substitution reaction of ethane with Cl2?
Chloroethane and hydrogen chloride
Explain why the reactivity of alkali metals increases as you move down Group 1, while the reactivity of halogens decreases as you move down Group 17.
Alkali metals become more reactive down the group because it is easier to lose an electron.
Halogens become less reactive down the group because it is harder to gain an electron.
Explain why a salt bridge is necessary in a galvanic cell.
What would happen to the cell’s operation if the salt bridge were removed?
The salt bridge is important to ensure the electroneutrality of the solutions and to complete the circuit.
The cell will stop operating if the salt bridge is removed since the circuit becomes opened.
Why can alkenes and alkynes undergo addition reactions?
Since both are unsaturated and the double/triple bond can be broken down.