Basics
List the 3 subatomic particles that compose an atom and their charges.
Protons - positive charge, Neutrons - neutral or no charge, Electrons - negative charge.
Balance the following equation:
_ N2 + _ F2 -> _ NF3
1 N2 + 3 F2 -> 2 NF3
a. An electron transfers from each sodium atom to each chlorine atom.
b. An electron transfers from each chlorine atom to each sodium atom.
c. Sodium and chlorine atoms share electrons.
a. An electron transfers from each sodium atom to each chlorine atom.
A chemical reaction has NOT occurred if the products have:
a. The same mass as the reactants.
b. More energy than the reactants.
c. Less energy than the reactants.
d. The same chemical properties as the reactants.
d. The same chemical properties as the reactants.
True or False: Elements are composed of 2 or more substances?
False!
Name the following compound: Be(HCO3)2
Beryllium bicarbonate
What is Avogadro's Number? State the definition AND the numerical value.
The number of units in one mole of any substance, which equates to 6.022 x 10^23 mol^-1.
Explain the octet rule and at least one exception to this rule:
Atoms gain or lose electrons to attain an outer shell electron configuration nearest that of a noble gas.
Exceptions include hydrogen, beryllium, boron.
The reaction 2KClO3 (s) -> 2KCL (s) + 3O2 (g) is what type of reaction being portrayed?
Decomposition reaction.
215.15 K is converted to _ degrees C.
-58.
List the significant figures for the following questions. It's all or nothing :)
a) 75,000.0 m
b) 0.07505 m
c) 75,000 m
a) 6
b) 4
c) 2
How many moles of LiCl will be formed by the reaction of Cl2 with 0.046 moles of LiBr in the respective reaction?
0.046 moles LiCl
Explain the 4 types of bondings present in Chemistry and match the respective example for each:
a) H2O - H2O
b) Br2
c) Cu2+
d) NaCl
Ionic: Metal and Non-metal, D
Covalent: Non-metal and Non-metal, B
Hydrogen: Hydrogen attracting electronegative atom, A
Metallic: Positive metal ions conducting elections, C
Write the reaction equation of barium nitrate and sodium sulfate, listed with the solubility level of each compound.
Ba(NO3)2 (aq) + Na2SO4 (aq) -> BaSO4 (s) + 2Na(NO3) (aq)
Identify the element based on their symbol:
a. Au
b. Pb
c. Fe
Gold, Lead, Iron
The density of mercury is 15.4 g/mL. What is the mass in kilograms of a 2 L commercial flask of mercury? Set up the problem so that the calculation will yield a result with a mass in grams.
15.4 g X 1000 mL X 2 L X 1 kg = 30.8 kg
1 mL 1 L 1000 g
Use the following equation: 2 NaOH + H2SO4 -> 2 H2O + Na2SO4
How many grams of sodium sulfate will be formed if you start with 200 grams of sodium hydroxide and you have an excess of sulfuric acid?
355 g Na2SO4.
Which type of attraction results from the formation of weak momentary dipoles?
Var-der-Waals forces.
The balanced net ionic equation for precipitation of CaCO3 when aqueous solutions of NA2CO3 and CaCl2 are mixed is:
Ca2+ (aq) + CO32- (aq) -> CaCO3 (s)
The elements F2, Cl2, Br2, and I2 all belong to the _ family and all have similar _ properties.
Halogen, Chemical.
If you are going 55 mph, what is your speed in m per second?
1 mile = 1.61 km.
55 mi / 1 hr x 1 hr / 60 min x 1.61 km / 1 mile x 1000 m / 1 km = 25 m/sec.
For the following problem, use the following chemical equation:
C8H18 + O2 -> CO2 + H2O
a) Balance the equation.
b) How many liters of carbon dioxide gas are formed at STP when 3.829 x 10^25 representative particles of C8H18 are reacted in an excess of oxygen gas?
a) 2 C8H18 + 25 O2 -> 16 CO2 + 18 H2O
b) 1.140 x 10^4 L CO2
Diamond:
a. Describe the structure.
b. List at least one of its properties.
a. Each carbon atom is covalently bonded to four others.
b. High melting point, hard, doesn't conduct electricity.
Which of the following solutions, when added to a solution of Na2SO4 would form a precipitate?
I. AgNO3 (aq)
II. KNO3 (aq)
III. CaCl2 (aq)
I and III only.
A sample in a weigh boat is weighed as 10.5 g. The weigh boat has a mass of 5.6g. The sample is added to a beaker containing 0.021 L of water and it now reads 0.034 L. The sample has a density of _ (g/mL).
0.38 g/mL.