Exam 1
Is bread molding a chemical or physical change?
chemical change
What is the sign of H in an endothermic reaction?
positive
What does it mean when two atoms or ions are isoelectronic?
They have the same electron configuration
Is NH3 polar or nonpolar?
Polar
What is 723 mmHg in atm?
0.951 atm
What is the scientific notation associated with the prefix centi?
10-2
What is the precipitate formed when sodium phosphate and calcium nitrate react in a precipitation reaction?
Ca3(PO4)2
Describe first ionization energy
The energy required to remove an electron
What is the molecular geometry of SCl4
see saw
What process is responsible for the difference in smell of a spray of perfume over time?
molecular diffusion
What is the name for HF
hydrofluoric acid
What is the oxidation state of Cr in CaCrO4?
+6
What are valid values for the magnetic quantum number for an electron in the 4d subshell
-2, -1, 0, 1, 2
Which of the following has the longest bond length
C-N, C-O, or C-C
C-C
If the mol fraction of Ar in air is 0.00934, what is the partial pressure of Ar if the total pressure is 834 torr?
7.79 torr
There are ___ protons, ____ neutrons, and _____ electrons in 238U+5
92 p+
146 n0
87 e-
Calculate the heat in kJ required to raise the temperature of 55.8 g of benzene by 48.8 K. The specific heat capacity of benzene is 1.05 J/goC.
2.86 kJ
What oxide compounds dissolve in water to produce an acidic solution?
nonmetal oxides
Determine the hybridization of the central atom in BF3
sp2
Explain why the boiling point of CH3Cl (-24.2°C) is higher than that of CH4 (-161.6°C)
CH3Cl has dipole-dipole forces
Lithium and nitrogren react to produce lithium nitride:
6Li (s) + N2 (g) --> 2Li3N (s)
How many moles of N2 are needed to react with 0.500 mol of Lithium
0.0833 mol N2
What is the molarity of a NaOH solution if 15.5 mL of a 0.220 M H2SO4 solution is required to neutralize a 25.0 mL sample of the NaOH solution?
0.273 M
When the electron in a hydrogen atom moves from n=5 to n=2, light with a wavelength of ____ nm is emitted.
434 nm
Draw the best lewis structure for CBr3+. What is the formal charge on C?
+1
A 5.00 L mixture of helium, neon, and argon has a total pressure of 854 mmHg at 234 K. If the partial pressure of neon is 43 mmHg and the partial pressure of helium is 652 mmHg what is the mass of argon present in the mixture?
2.18 g Ar