Chemistry Test #2
Calculate the molar mass for the following compound: HNO3
H= 1.008; N= 14.007, O3= 48.000 1.008 + 14.007 + 48.000= 63.02
Complete and balance the following acid-base reaction: HCl + Ba(OH)2=
HCl + Ba(OH)2= H2O + BaCl2 2 HCl + Ba(OH)2= 2 H2O + BaCl2
List the number of valence electrons in each of the following elements: O, S, Br, Rb.
O= 6; S= 6; Br= 7; Rb= 1
Determine whether the following compounds are soluble or insoluble. K2S, PbSO4, K2SO4, Hg2I2, BaS, Cu3(PO4)2, Li2S, MgS, SrS, CaSO4, NH4Cl, Hg2Cl2, Na2CO3, PbCl2
Soluble= K2S, K2SO4, BaS, Li2S, SrS, NH4Cl, Na2CO3 Insoluble= PbSO4, Hg2I2, Cu3(PO4)2, MgS, CaSO4, Hg2Cl2, PbCl2
Define solvent
The component of a solution that is present in the greatest amount. It is the substance in which the solute is dissolved.
Use the periodic table to identify the element with the following electron configuration: [Kr] 5s^1
[Kr] 5s^1= Rb
Use the periodic table to identify the element with the following electron configuration: [Ne] 3s^2 3p^5
[Ne] 3s^2 3p^5= Cl
Define aqueous solution
a solution in which water is the solvent
Define strong electrolyte
all or nearly all of the solute exists as ions; e.g. HCl
Define precipitate
an insoluble solid product that separates from the solution
List the properties of ionic compounds.
brittleness, high melting points, suability and electrical conductivity
Which type of electromagnetic radiation has the longest wavelength? a) visible b) ultraviolet c) infrared d) X-ray
c) infrared
List the common diatomic molecules.
H2, N2, O2, F2, Cl2, I2, Br2
A pure gold coin contains 0.145 moles of gold. What is the mass?
(0.145 mol Au) (196.967 g/ 1 mol Au)= 28.6 g
Using the following equation, 2 K + Cl2= 2 KCl, calculate the theoretical yield of product in moles for each of the initial quantities of reactants. 1 mol K; 1 mol Cl2
(1 mol K) (2 mol KCl)/(2 mol K) = 1 mol KCl (1 mol Cl2) (2 mol KCl)/ 1 mol Cl2)= 2 mol KCl 1 mol K= theoretical yield
For the reaction shown calculate how many moles of NO2 form when 1.3 moles of N2O5 completely reacts?
(1.3 mol N2O5) (4 mol NO2/2 mol N2O5)= 2.6 moles NO2
How many atoms are in a 16.9 g sample of Sr?
(16.9 g Sr) (1 mol Sr/87.62 g) (6.022 x 10^23/ 1 mol Sr)= 1.16 x 10^23
For the reaction shown, calculate how many grams of oxygen form when 2.13 g of HgO completely reacts. 2 HgO= 2 Hg + O2
(2.13 g HgO) (1 mol HgO/ 216.592) (1 mol O2/ 2 mol HgO) (32.00 g/1 mol O2)= 0.157 g O2
Determine the number of moles of C in a 2.5 mol sample of CH4.
(2.5 mol CH4) (1 mol C/ 1 mol CH4)= 2.5 moles C
Determine the number of moles of Cl in 2.7 mol of CaCl2.
(2.7 mol CaCl2) (2 mol Cl/1 mol CaCl2)= 5.4 moles Cl
How many atoms are in 3.4 moles of Cu?
(3.4 mol Cu) (6.022 x 10^23/ 1 mol Cu)= 2.0*10^24
How many grams of Cl are in a 38.0 g sample of CF2Cl2? molar mass of CF2Cl2= 120.913
(38.0 g CF2CL2)(1 mol CF2Cl2/120.913 g)(2 mol Cl/1 mol CF2Cl2)(35.453 g/ 1 mol Cl)= 22.3 g of Cl
How many moles of tin atoms are in a pure tin cup with a mass of 38.1 g?
(38.1 g Sn) (1 mol Sn/118. 711 g)= 0.321 moles Sn
Determine the number of moles in a 38.2 g sample of sodium chloride (NaCl).
(38.2 g NaCl) (1 mol NaCl/ 58.44g)= 0.654 moles
Write the formula for percent yield.
(actual yield)/(theoretical yield) X 100= % yield
Below is the unbalanced reaction for the combustion of butane. Balance the equation and determine how many moles of O2 are needed to react completely with 4.9 moles of C4H10. C4H10 + O2= CO2 + H20
2 CH4H10 + 13 O2= 8 CO2 + 10 H20 (4.9 mol C4H10) (13 mol O2/ 2 mol C4H10)= 32 moles O2
Define solution.
A homogeneous mixture of two or more substances
Define soluble.
A substance that dissolves in the solvent
Define insoluble.
A substance that does not dissolve in a solvent
Name the following molecular compound: CO2
Carbon dioxide
Identify the following reaction as a combination, single displacement, double displacement, combustion, or decomposition reaction: C +O2= CO2
combination
Identify the following reaction as a combination, single displacement, double displacement, combustion, or decomposition reaction: CH4 +2O2= CO2 +2H2O
combustion
What are molecular compounds?
compounds formed from two or more nonmetals
What are binary ionic compounds?
compounds that contain two different elements, a metal and a nonmetal
Identify the following reaction as a combination, single displacement, double displacement, combustion, or decomposition reaction: CaCO3= CaO +CO2
decomposition
Define immiscible
describes liquids that are insoluble in one another
Identify the following reaction as a combination, single displacement, double displacement, combustion, or decomposition reaction: Mg+ 2HCl= MgCl2 +H2
double displacement
Name the following acid: HCl
hydrochloric acid
Define miscible
liquids (or other substances) that mix together
Find the mass percent composition of Ca and Cl in CaCl2. mass percent composition= molar mass of element/ molar mass of compound X 100
molar mass of CaCl2= 110.986 (1 mol Ca) (40.08/1 mol Ca)= 40.08/110.986= 0.3611 X100= 36.1% Ca (2 mol Cl) (35.453/ 1 mol Cl)= 70.96/110.986= 0.6393 X 100= 63.9% Cl
Name the following hydrate: NiSO4 * 6H2O
nickel(II) sulfate hexahydrate
List the types of electromagnetic radiation in order of increasing energy per photon.
radio waves<microwaves<infrared<ultraviolet
Know the shapes of the s, p, and d orbitals.
s= circle; p= bowtie; d= butterfly
Identify the following reaction as a combination, single displacement, double displacement, combustion, or decomposition reaction: Fe +CuCl2= FeCl2 + Cu
single displacement
Name the following acid: H2SO4
sulfuric acid
Define solute
the component of a solution that is present in the lesser amount. It is the substance being dissolved.
Define solubility
the maximum amount of a given solute that will dissolve in a given amount of solvent
