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Acid Base Reactions Quiz
Radioactivity Quiz
Water & Its Solutions Quiz
100
Net ionic equation do not show ions that are common to both reactants and products. (question # 4)
Are spectator ions included in net ionic equations? Explanation: Spectator ions are the ions that are common to both the reactants and products and are removed before writing the net ionic reaction. They do not appear in net ionic equations. Example: 2Na+(aq) + 2Cl−(aq) + Cu2+(aq) + SO4 2−(aq) → 2Na+(aq) + SO42−(aq) + CuCl2 (s) results in this equation: 2Cl−(aq) + Cu2+(aq) → CuCl2 (s) Na and SO4 are spectator ions.
100
The number of electrons in the atom decreases by one. (Question #4)
What is beta emission? Explanation: Beta emission happens when a neutron breaks down into a proton and an electron. The atomic number would increase (because a neutron was changed into a proton), but the mass number would remain the same.
100
Water is often referred to as this. (Question #1)
What is the universal solvent: Explanation: Water can dissolve many ionic and covalent compounds because it has hydrogen-bonds, which can dissolve and pull apart many of these compounds.
200
2 H+ (aq) + Co(OH)2 (aq) ---> Co+2 (aq) + 2 H2O (l) (question 6)
Which is the correct net ionic equation for the following reaction: 2 HBr (aq) + Co(OH)2 (aq) ---> CoBr2 (aq) + 2 H2O (l)? Explanation: in these type equations, break apart the soluble molecules into the two ions that are formed (one positive and one negative). Then cancel out spectator ions. In this case HBr and CoBr2 are soluable, and the Bromine becomes a Spectator Ion.
200
An average of 50% of the atoms have decayed in an element. (Question #8)
What is half-life of an element? Explanation: Half-life is the time it takes for one-half of a particular radioactive element sample to undergo radioactive decay. Half-life is different for each radioactive elements. Atoms that did not decay in previous half lives have an equal chance of decaying in the next half-life.
200
Sugar is left behind as a solute. (question 8)
What happens to sugar when it is boiled with water? Explanation: Water is boiled and evaporates. The sugar molecules are the only thing left behind. Remember, water formed a "sphere of hydration" around the sugar and is free to vaporize when boiled.
300
H3BO3 (aq) + OH− (aq) --- >BO3− (aq) + H2O (l) (question #9)
Give an example of a net ionic equation that represents a weak acid-strong base reaction? Explanation: H3BO3 (Boric Acid) is a weak acid and OH- is a strong base. KOH is also a strong base but OH- has a greater pH (14 compared to 12.7.)
300
an increase in solubility (question #9)
What happens in an endothermic solution process when the temperature is increased? Explanation: If the solution process absorbs energy, then the solubility will increase as the temperature increases. Solubility is a measure of the maximum amount of solute that can be dissolved in a given amount of solvent to form a stable solution. So this makes sense - more energy, more collisions of molecules, and therefore it will dissolve more quickly.