Exam 1
How many significant figures are in each of the following measurements?
a. 11,050
b. 0.0159 s
c. 20.50 g
d. 1.00 X 10^5 L
a. 4
b. 3
c. 4
d. 3
Place Ca2+, S2−, Cl−in order of increasing radius.
Ca2+ < Cl− < S2−
What mass of sulfur is contained in 25.6 g of Al2(S2O3)3, 390.3 g/mol?
12.6 g
Which of the following visible colors of light has the highest frequency? The lowest frequency?
A. red
B. orange
C. yellow
D. blue
E. green
highest: blue
lowest: red
Consider the compounds: Li3N, PH3, C2H6, IBr3. Which are ionic compounds?
A. C2H6 only
B. Li3N only
C. Li3N and PH3
D. PH3 and C2H6
E. PH3, C2H6 and IBr3
B
What are the signs of q and w for the following phase change at constant pressure and constant temperature
H2O(g) → H2O(l)
A. q and w are positive
B. q is positive, w is negative
C. q is negative, w is positive
D. q and w are both positive
E. q and w are both zero
C
A person is most likely to experience serious detrimental biological effects when exposed to which of the following forms of electromagnetic waves?
A. ultraviolet
B. microwaves
C. infrared
D. x-rays
D.
Give the ground state electron configuration for Br−.
[Ar]4s2 3d10 4p6
Which of the following substances will dissolve and dissociate completely when mixed with water?
A. AgCl
B. HClO4
C. NH3
D. CH3OH
B
Calculate the wavelength (in nm) of the red light emitted by a neon sign with a frequency of 4.74 × 10^14 Hz.
632 nm
Draw the Lewis structure for SO4^2-. How many equivalent resonance structures can be drawn?
6
What is the theoretical yield, in grams, of sodium sulfate when 2.0 g of sulfur reacts with 3.0 g of oxygen and 4.0 g of sodium hydroxide according to the following chemical equation?
2 S + 3 O2 + 4 NaOH → 2 Na2SO4 + 2 H2O
7.10 g
A piece of iron at 353 K is drooped into room temperature water, 22 degrees C. Consider the piece of iron to be the system.
1. Does the system gain or lose heat?
2. Does the surroundings gain or lose heat?
3. Is delta T system positive or negative?
4. Is delta T surroundings positive or negative?
1. System loses heat
2. Surroundings gain heat
3. Delta T system is negative
4. Delta T surroundings is positive
How many lone pairs of electrons are on the Xe atom in XeF6?
1
In the balanced chemical reaction, the coefficient on HBr is ___.
___ CH3Br + ___NH3 → ___(CH3)3NHBr + ___HBr
2