1. The answer is A hydrogen ion donor in a reaction. On the other hand a base is a substance that increases the hydroxide ion concentration of a solution. How strong an acid depends on the degree of dissociation to release H+ ions in water
2. The answer is It has a pH value below 7. pH is logarithm base 10 of the reciprocal of the amount of H+ions in a solution. Acids have a sour taste while bases have bitter tastes. Acids also turn litmus paper red.
3. The answer is ammonia. Aqueous ammonia is basic in pH (pH above 7). The other given choices are acids or dissociates into acids in aqueous form. When a base and acid are mixed, the products are water and salts in a process called neutralization.
4. The answer is It has a higher concentration of hydroxide ions than hydronium ions. As indicated in question 1, while acids dissociate to release more of H+ ions, bases dissociate to release more of –OH ions. The stronger the base the more it dissociates –OH ions in water.
5. The answer is The forward and reverse reactions eventually reach the same rate. This occurs when in the forwards reaction the reactants form products, and subsequently, the products also reverse back to the former reactants. The forward process begins and continues until there are enough products and the reversing back of products to reactants is in equilibrium with the forward reaction.
6. The answer is Adding H2O (g) to the system. Increasing reactants in a chemical reaction pushes the reaction forwards. Also reducing the products also pushes the reaction forwards. The reverse also applies where increasing the products pushes the reaction in the reverse.
7. The answer is Lowering the temperature of the reaction. According to the reaction, it release heat as a product hence it is exothermic. Removing this heat energy by keeping the reaction cool pushes the reaction forward. This is tantamount to reducing products in the reaction.
8. The answer is The element that is oxidized loses electrons, and the element that is reduced gains electrons. An example of redox reaction is rusting process and combustion.
9. The answer is Iron is oxidized because it lost electrons. Oxygen is reduced, on the other hand, by accepting an electron from iron. This is why Iron turns from iron II to iron III in rusting process.
10. The answer is Only nuclear reactions can change the identity of the atom. In nuclear reaction, a heavy element atom decays into another element atom and releases a neutron and energy. In chemical reactions, atoms remain the same, they only make new bonds with one another.
11. The answer is Both reactions release energy; in a fission reaction, one atom splits into two smaller atoms, while in a fusion reaction, two smaller atoms combine to form one larger atom. An example of Fusion reaction is that which occurs in the center of the stars while a fission reaction is that which occurs in nuclear fission bombs.
