Exam 1
Arrange the elements in order of increasing ionization energy: Te, Pb, Cl, S, Sn.
Pb < Sn < Te < S < Cl
Name/ write the formula for the following:
Lead (IV) Oxide
dinitrogen heptoxide
KClO3
CS2
PbO2
N2O7
potassium chlorate
carbon disulfide
At 137 degrees Celsius and under a pressure of 3.11 atm, a 276 g sample of an unknown noble gas occupies 13.46 L of space. What is the gas?
222.58 g/mol
RADON (Rn)
Define acidic, basic, and neutral solutions
ex. [H3O+]>[OH-]
Define acidic, basic, neutral using the pH scale
[H3O+]>[OH-] acidic (pH<7) [H3O+]> 1.0 x 10^-7
[H3O+]=[OH-] neutral (pH=7) [H3O+]=1.0x 10^-7
[H3O+]<[OH-] basic (pH>7) [H3O+]< 1.0x10^-7
Determine electron and molecular geometry for
A. Nitrite
Electron: trigonal planar
Molecular: Bent
Polar
a. 600 ul= ___ ml
b. 765 ng= ___ Kg
c. 6732dm= ___ cm
0.6 ml
7.65 x 10^-10kg
67320 cm
How much heat is needed to warm 250 g of water from 22 celsius to 98 celsius?
C=4.184 J/g K
7.9x 10^4
1.00 L of a solution is prepared by dissolving 125.6 g of NaF in it. If I took 180 mL of that solution and diluted it to 500 mL, determine the molarity of the resulting solution.
1.08 M
Aniline (C6H5NH2) is slightly soluble in water. It has a Nitrogen atom that can accept a hydrogen ion from a water molecule just like the nitrogen atom in ammonia does. Write the chemical equation for this reaction and identify the Bronsted-Lowry acid and base.
C6H5NH2 (aq) + H2O (l) <- -> C6H5NH3 (aq) + OH- (aq)
C6H5NH2 is base
H2O is acid
Write out the balanced single replacement reaction that occurs when you react aluminum with copper (II) sulfate
2 Al + 3 CuSO4 -> Al2(SO4)3 + 3 Cu
write the abbreviated electron configuration for each of the following:
a. Carbon
b. Antimony
c. Fluoride
a. [He]2s2 2p2
b. [Kr]5s2 4d10 5p3
c. [He]2s2 2p5
2NH3(g)-><- N2 (g) + 3 H2 (g)
At 500K, the following concentrations were measured:
[N2]= 3.0 x10^-2 M
[H2]= 3.7 x 10^-2 M
[NH3]= 1.6 x 10^-2 M
What is Kc?
5.9 x 10^-3
Name the following:
H2SO4
HNO3
H2SO3
HI
Write the formula for the following:
Chlorous acid
Hydrofluoric acid
Hydrobromic acid
Phosphoric acid
Sulfuric acid
nitric acid
sulfurous acid
hydroiodic acid
HClO2
HF
HBr
H3PO4
What is being oxidized and what is being reduced?
2 Fe2O3(s)+3 C(s)→4 Fe(s)+3 CO2(g)
C is being oxidized
Fe is being reduced
what are the following number of protons, neutrons, and electrons in the following:
a. 89Sr
38
b. 52 Cr
24
a. p=38 n=51 e=38
b. p=24 n=28 e= 24
1. Os-182 has a half-life of 21.5 hours. How many grams of a 10-gram sample would have decayed after exactly 3 half-lives?
How many hours would pass if it goes through 3 half-lives?
2. An element has a half-life of 35.5 years, how much of a 94.5g sample of the element will be left in 177.5 years?
1a. 8.75 g
1b. 64.5 hr
2. 2.95g
NH3 + O2 -> NO + H2O
3.25 g of NH3 are allowed to react with 3.50g of O2
A. Which is limiting reactant?
B. How much NO is formed in g
A. O2
B. 2.63 g NO
For the follwoing endothermic reaction, which change would cause the equilibrium to shift to the right?
CH4 (g) + 2H2S (g) <- -> CS2 (g) + 4H2
a. decrease concentration of 2H2S
b. Increase pressure on the system
c. increase the temp of the system
d. increase the concentration of CS2
e. Decrease the concentration of methane (CH4)
c. Increase the temp of the system because a decrease in temp favors exothermic reactions.
For each reaction, calculate how many moles of product form when 1.75 mol of the reactant in italics. Assume there is more than enough of the other reactant.
H2(g)+Cl2(g)→2 HCl(g)
2 H2(g)+O2(g)→2 H2O(l)
1. 3.50 mol of HCl
2. 3.50 mol of H2O
How much heat in kilojoules is evolved in converting 1.00 mol of steam at 145 °C to ice at –50.0 °C? The specific heat capacity of steam is 1.84 J/g °C and that of ice is 2.09 J/g °C.
57.5 kJ
What mass of O2 will be needed to burn 36.1g of B2H6
B2H6 + O2 -> HBO2 + H2O
125 g
A sample of argon gas at STP occupies 56.2 L. Determine the number of moles of argon and the mass of argon in the sample.
2.509 moles
100. grams
A popular soft drink has a pH of 3.4. What is it's hydronium (H3O+) ion concentration?
4.0 x 10^-4 M
how many grams of water would require 2,200 joules of heat to raise its temperature from 34 degrees Celsius to 100 degrees Celcius?
7.974 g