Exam 1
What is the overall charge of a perchlorate ion?
-1
Which of the following has the greatest number of valence electrons?
Si
As
Ga
Sr
Ra
As
What is the ideal bond angle between oxygen sulfur bonds on the molecule SO32-?
109.5
sodium chloride changing from a gas to a solid is an example of what?
deposition
Which element goes from an oxidation number of -2 to +6?
3CuS + 8HNO3 --> 3 CuSO4 + 8NO + 4H2O
S
If a hazardous bottle is labeled 15.3 percent by mass HCl, with a density of 1.096 g/mL, calculate the molarity of the HCl solution.
4.60 M
A system undergoes a change, resulting in the internal energy increasing by 80.J, during the change the system had 50.J of work done to it. What was the heat change of the system?
30. J
How many resonance structures are possible for NO3-?
3
What is the central electron geometry of ClF4-?
octahedral
One of the fastest recorded kicks of a soccer ball registered the speed of the ball at 182 km/h. If the average soccer ball has a mass of 426 g and a diameter of 22.0 cm, what was the wavelength of this ball?
3.08 x 10-35 m
Vitamin C (MW= 176.12 g/mol) is a compound of C, H, and O found in many natural sources. When a 1.000 g sample of vitamin C is placed in a combustion chamber and burned, elemental analysis shows that this compound contains 1.50 g of CO2 and 0.41 g of H2O. What is the empirical formula of vitamin C?
C3H4O3
If a system loses 250 kJ of heat at the same time that it is doing 500 kJ of work, what is the change in the internal energy of the system?
-750 kJ
What is the molecular structure of thionyl chloride: Cl2SO
trigonal pyramidal
What is the dominant intermolecular force in ICl?
dipole dipole
What is the total pressure in atm when 1.00 mol of Ar, 0.400 mol of He, and 1.60 mol of N2 gases are injected into a 9.12 L flask at 0.00C? What is the partial pressure of He?
7.37 atm, 0.983 atm
4NH3 + 5O2 --> 4NO + 6H2O
Which element is being oxidized? What is the oxidizing agent?
element being oxidized: N
oxidizing agent: O2
The deployment of a cars airbag is driven by the decomposition of sodium azide. Using the decomposition reaction info, determine the enthalpy of formation for NaN3?
2NaN3 --> 3N2 + 2Na
ΔH = -43.5 kJ
21.8 kJ
You have inflated a balloon with air at 15.3 C to a pressure of 101.3 kPa, and a volume of 1.89 L. If the temperature of the gas inside the balloon decreases by 20.7 C, and the pressure remains the same, what will be the volume of the balloon?
1.75 L
Based off the principles of intermolecular forces, which of the following liquids will have the higher surface tension?
a. Hg
b. H2O
c. Ch3Ch2OCH2CH3
d. CH3CH2OH
e. CH3CH2CH2OH
a. Hg
It takes 15.9 minutes for 0.493 moles of HCN has to effuse from a porous container. If the same container is used to contain Rn (g) how many moles of radon will effuse from the container under the same conditions in 22.5 minutes?
0.244 mol
When 250. mL of a 0.15 M solution of ammonium sulfide (NH4)2S is poured into 120.mL of a 0.052 M solution of cadmium sulfate CdSO4, how many grams of a yellow precipitate of cadmium sulfide CdS are formed? The other product is (NH4)2SO4. (This is a limiting reagent problem)
0.92 g
A 5.000 g sample of methanol, CH3OH, was combusted in the presence of excess oxygen in a bomb calorimeter containing 4000.g of water. The temperature of the water increased from 24.000C to 29.765 C. The heat capacity of the calorimeter was 2657 J/C. The specific heat of water is 4.184 J/gC. Calculate the enthalpy of the reaction in kJ/mol.
-716.5 kJ/mol
Copper metal can be dissolved with nitric acid, and as a product of the reaction, nitrogen dioxide gas is formed. If a 19.5g piece of copper is placed in a container, what volume of gas will be produced at STP?
Cu + 4HNO3 --> Cu(NO3)2 + 2NO2 + 2H2O
13.7 L
Which one, if any, of the following statements about the MO treatment of the bonding in benzene is correct?
a. the lowest energy pi-bonding orbital in benzene can hold up to 6 electron
b. MO theory predicts that benzene should be paramagnetic
c. MO theory doesn't need resonance to describe the delocalized nature of the bonding in benzene
d. The localization of the pi electrons, often the double bonds, are represented by a circle in the middle of the hexagon
e. None of these choices are correct
c. MO theory doesn't need resonance to describe the delocalized nature of the bonding in benzene
White phosphorus is one of the elemental forms of phosphorus, have the molecular formula P4. White phosphorus will react rapidly with O2 in the atmosphere to form P4O10. If you have 23.84 g of white phosphorus and 22.51 g of oxygen in a 500.0 mL container, what will be the mass of P4O10? Which is the excess reagent and how much of it is left over once the reaction is complete?
39.94 g
P4: 6.41 g