Chapter 3 Practice Test
What is the mass in grams of NaCN in 120.0 mL of a 2.40 x 10^ -5 M solution?
1.41 x 10^-4 g NaCN
Determine the mass in grams of NaCl that are in 23.4 moles of NaCl?
1367 g
Determine the mass in grams of 3.00 × 10²¹ atoms of arsenic. (The mass of one mole of arsenic is 74.92 g.)
0.373g
Determine the number of atoms of O in 10.0 grams of C₆H₁₂O₆
2.00 x 10 ^23 atoms
If 50.0 g of CH₃OH (MM = 32.04 g/mol) are dissolved in 500.0 mL of solution, what is the concentration of CH₃OH in the resulting solution? (Assume the volume does not change after the addition of the solid.)
3.12 M
Determine the molar mass of Ag₃N?
337.62 g/mol
Determine the number of atoms of O in 92.3 moles of Cr₃(PO₄)₂.
4.45 x 10 ^26 atoms
How many oxygen atoms are in 1.5 moles of N2O4? A. 6 B. 4.0 x10^23 C. 9.0 x 10^23 D. 3.6 x 10 ^24 E. 4.8 x 10^24
D. 3.6 x 10^24
What is the mass of 20 moles of NH3? A. .85 g B. 8.5 g C. 17g D. 340 g E. 1.2 x 10^25 g
D. 340 g
How many molecules rae in a 48g sample of SO2? A. .25 B. .75 C. 2.25 D. 4.5 x 10^23 E. 1.4 x 10^24
D. 4.5 x 10^23
What is the mass percent of oxygen in HNO3? A. 12% B. 25% C. 51% D. 76% E. 89%
D. 76%
To convert from grams to number of molecules, you need to use: A) Avogadro's number B) Molar mass C) Density D) Both (A) and (B) E) None of the above
D. Both (A) and (B)
What is the molecular formula of a compound with an empirical formula of CH and a molar mass of 78.1 g/mol? A) C₆H B) C₂H₂ C) C₂H₆ D) C₆H₆
D. C6H6
Which of the following compounds is the molecular formula the same as the empirical formula? A. P4H10 B. C6H6 C. C6H10O2 D. CH3CH2OH E. H2O2
D. CH3Ch2OH
How many atoms are in 2 moles of HNO3? A. 8 B. 10 C. 126 D. 1.2x10^24 E. 6.0 x 10^24
E. 6.0 x 10^24
What volume in mL of 0.3000 M NaCl solution is required to produce 0.1500 moles of NaCl?
500 mL
What is the mass percentage of O in CO₂?
72.68 %
Determine the mass, in grams, of 0.400 moles of Pb (1 mol of Pb has a mass of 207.2 g).
82.9 g
What is the amss of 1.5 x 10^21 water molecules? A. .00018g B. .0018 g C. .045 g D. 4.5g E. 18g
C. .045g
There are 1.5 x 10^25 water molecules in a container. How many moles of water is this? A. 2 B. 10 C. 25 D. 45 E. 460
C. 25
What is the empirical formula of acetic acid, HC₂H₃O₂? A) HCO B) H₂C₄H₆O₄ C) H₂CO D) CO₂
C. H2CO
Empirical formula of C6H12O6? A. C6H12O6 B. C3H6O3 C. CH2O D. C2H4O4 E. none
CH2O
How many moles of calcium atoms do you have if you have 3.00 × 10²¹ atoms of calcium. (The mass of one mole of calcium is 40.08 g.)
.00498 mol
100.0 mL of a 0.500 M solution of KBr is diluted to 500.0 mL. What is the new concentration of the solution?
.100 M
What volume in liters of a .724 M NaI solution contains .405 mol of NaI?
.559 L
How many moles of C3H6 are in 25.0 grams of the substance (propylene)?
.594 mol C3H6
How would you determine the formula weight of NaCl? A) Add the mass of sodium (22.99 amu) plus the mass of chlorine together (35.45 amu). B) Multiply the mass of sodium (22.99 amu) by the mass of chlorine (35.45 amu). C) Divide the mass of chlorine (35.45 amu) by the mass by sodium (22.99 amu). D) Subtract the mass of chlorine (35.45 amu) from the mass of sodium (22.99 amu).
A.
How many moles are in a 45g sample of C6H12O6? A. .25 B. .5 C. 2 D. 4 E. 2.4 x 10^24
A. .25
The analysis of a compound shows it contains 5.4 mol C, 7.2 mol H, and 1.8 mol N. What is the empirical formula of the compound? A) C₃H₄N B) C₄H₃N C) C₅.₄H₇.₂N₁.₈ D) CH₁.₃N
A. C3H4N
Which of the following would have the greatest mass percent of iron? A. FeO B. FeS C. Fe2O3 D. FeBr3 E. FeBr
A. FeO
A compound is 50% S and 50% O. Which of the following is this compound? A. SO2 B. S2O3 C. SO3 D. SO E. S2O
A. SO2
Mass percent of titanium in TiCl2? A. 22% B. 40% C. 57% D. 71% E. 87%
B. 40%
What is the mass of 1.2 moles of NaOH? A. 32g B. 48 g C. 80 g D. 5.2 x 10 ^23 g E. 7.2 x 10^23 g
B. 48 g
A compound that contains only carbon, hydrogen, and oxygen is 58.8% C and 9.87% H by mass. What is the empirical formula of this substance? A) C₂.₅H₅O B) C₅H₁₀O₂ C) C₆H₄O D) C₄H₈O₂ E) C₅H₅O₂
B. C5H10O2
The empirical formula of a compound is CH and molecular weight = 78amu. Which of the following is this compound? A. C5H18 B. C6H6 C. C4H14O D. C4H4 E.C5H5
B. C6H6
How many molecules are in 3 moles of CO2? A. 14.7 B. 44 C. 132 D. 2.0x10^23 E. 1.8 x 10^24
D. 2.0 x 10^23
