Chapter 1
classify each of the following changes as chemical or physical: whipping cream, ripening of banana, lighting a candle
whipping cream: physical
ripening of banana: chemical
lighting a candle: chemical
What is the formula for the perchlorate ion, carbonate ion, and sulfite ion?
Perchlorate: ClO4-
Carbonate: CO3 2-
Sulfite: SO3 2-
In the laboratory, a student adds 42.7 mL of water to 11.3 mL of a 0.520 M perchloric acid solution. What is the concentration of the diluted solution? Assume the volumes are additive.
0.109 M
Classify each of the compounds as soluble or not soluble: barium sulfate, aluminum nitrate, & ammonium phosphate
not solublE, soluble, & soluble
Classify the following materials as pure substances or mixtures: air, tomato juice, barium bromide.
air: homogeneous mixture
tomato juice: heterogenous mixture
barium bromide: substance, compound
Which of the following are characteristics of main-group metals?
A. have low first ionization energies.
B. are located along the diagonal line from B to Te.
C. have high first ionization energy.
D. are located on the left and towards the bottom of the periodic table
A & D
How many mL of a 0.204 M aqueous solution of cobalt(II) nitrate, Co(NO3)2, must be taken to obtain 12.8 grams of the salt?
343 mL
According to the following reaction, how many grams of chlorine gas are necessary to form 0.151 moles carbon tetrachloride? carbon disulfide (s) + chlorine (g) carbon tetrachloride (l) + sulfur dichloride (s)
42.8 g
How many significant figures?
a) 970.0
b) 3399000.0
c) 2107.0
d) 954600
a) 4
b) 8
c) 5
d) 4
a) What is the name of the compound with the formula CoS & SO3?
b) What is the formula for phosphorus trichloride & copper(I) sulfate?
a) cobalt(II) sulfide & sulfur trioxide
b) Cu2SO4 & PCl3
Calculate the mass percentage of carbon in a mixture that contains 128 grams of sodium bicarbonate (NaHCO3) and 134 grams of adipic acid (C6H10O4).
32.2%
Identify the species oxidized, the species reduced, the oxidizing agent and the reducing agent in the following electron transfer reaction. Pb2+ + Mg --> Pb + Mg2+
O.A./Reduced: Pb2+
R.A./Oxidized: Mg
An object with a mass of 49.8 pounds is moving with a uniform velocity of 54.9 miles per hour. Calculate the kinetic energy of this object in joules. Hints:
EK = ½(mass)(velocity)2; 1 lb = 453.59 g; 1 km = 0.62137 mi; 1 J = 1 kg m2/s2
6.80 x 10^3 J
The first has an atomic mass of 7.0160 amu and a percent natural abundance of 92.58 %. The second has an atomic mass of 6.0150 amu and a percent natural abundance of 7.42 %. What is the atomic weight of the element?
6.942 amu
A compound is found to contain 52.13 % carbon, 13.15 % hydrogen, and 34.72 % oxygen by weight. What is the empirical formula for this compound? The molecular weight for this compound is 46.08 g/mol. What is the molecular formula for this compound?
E: C2H6
M: C2H6O
For the following reaction, 0.362 moles of hydrogen gas are mixed with 0.347 moles of iodine.
H2 (g) + I2 (s) --> 2HI (g)
a. What is the formula for the limiting reagent? b. What is the maximum amount of hydrogen iodide that can be produced in moles?
a) I2
b) 0.694 moles
Taking the density of niobium metal to be 8.57 g/cm3, calculate the mass of metal needed to form a piece of Nb wire with the same length as the distance in b, but with a diameter of 1.00 mm. Hint: The volume of a cylinder is π times its radius squared times its height. (V = π r2 h)
3.25 g
It is often possible to change a hydrate into an anhydrous compound by heating it to drive off the water (dehydration). Write an equation that shows the dehydration of manganese(II) sulfate pentahydrate.
MnSO4 x 5 H2O --> MnSO4 + 5 H2O
A solution consists of 26.3 g of potassium bromide (KBr), 145.7 g water, and has a volume of 154 mL. Calculate the weight percent of KBr, the molality of KBr, the mole fraction of KBr, and the molarity of KBr in the solution.
15.3%
1.52 m
2.66x10^-2
1.43 M
A 2.741 gram sample of an organic compound containing C, H and O is analyzed by combustion analysis and 4.885 grams of CO2 and 2.000 grams of H2O are produced. In a separate experiment, the molar mass is found to be 74.08 g/mol. Determine the empirical formula and the molecular formula.
E: C3H6O2
M: C3H6O2