Transcript Answer - luvidinha

MOL Concept
Warmups
1. The gram-formula mass of a compound is 48 grams.
The mass of 1.0 mole of this compound is –
A. 1.0 g
B. 4.8 g
C. 48 g
D. 480 g
Answer
C is the correct answer.
2. How many moles are in 59.6 grams of BaSO4?
A) 0.256 mole
B) 3.91 moles
C) 13.9 moles
D) 59.6 moles
Answer
A is the correct answer.
3. How many molecules are contained in 55.0 grams of
H2SO4?
A) 0.561 molecules
B) 3.93 molecules
C) 3.38 X 1023 molecules
D) 2.37 X 1024 molecules
Answer
C is the correct answer.
4. If a sample of magnesium has a mass of 60. grams,
how many moles of magnesium does the sample
contain?
A)
1.1 moles
B) 1.2 moles
C) 2.0 moles
D) 2.5 moles
Answer
D is the correct answer.
5. Analysis shows a compound to be, by mass, 43.8% N,
6.2% H, and 50.0% O. Which is a possible molecular
formula for the compound?
A)
NH4NO2
B) NH4NO3
C) NH3OH
D)
N2OH
Answer
A is the correct answer.
6. A compound has an empirical formula of CH2O and
a molecular mass of 180 grams. What is the
compound’s molecular formula?
A) C3H6O3
B) C6H12O6
C) C6H11O7
D) C12H22O11
Answer
B is the correct answer.
7. What is the percent by mass of iron in the
compound Fe2O3?
A) 70 %
B) 56 %
C) 48%
D) 30 %
Answer
A is the correct answer.
8. What is the percent composition by mass of sulfur in
the compound MgSO4 (gram-formula mass = 120.
grams per mole)?
A. 20%
B. 27%
C. 46%
D. 53%
Answer
B is the correct answer.
9. Given the balanced equation representing a reaction:
2H2+ O2→ 2H2O
What is the mass of H2O produced when 10.0 grams of
H2 reacts completely with 80.0 grams of O2?
A.
B.
C.
D.
70.0 g
90.0 g
180. g
800. G
Answer
B is the correct answer.
10. Given two formulas representing the same compound:
Formula A
CH3C2H6
Formula B
CH6C4H12
Which statement describes these formulas:
A. Formulas A and B are both empirical.
B. Formulas A and B are both molecular.
C. Formula A is empirical, and formula B is molecular.
D. Formula A is molecular, and formula B is empirical.
Answer
C is the correct answer.
11. The sum of the atomic masses of the atoms in
one molecule of C3H6Br2is the–
A. formula mass
B. isotopic mass
C. percentage abundance
D. percentage composition
Answer
A is the correct answer.
12. The percent composition by mass of nitrogen in NH4OH
(gram-formula mass = 35 grams/mole) is equal to –
A. 4/35 X 100
B. 14/35 X 100
C. 35/14 X 100
D. 35/4 X 100
Answer
B is the correct answer.
13. Given the balanced equation representing a reaction:
2NaCl(ℓ) →2Na(ℓ) + Cl2(g)
A 1170. gram sample of NaCl(ℓ) completely reacts, producing 460.
grams of Na(ℓ). What is the total mass of Cl2(g) produced?
A
355 g
B
710. g
C.
1420. g
D.
1630. g
Answer
B is the correct answer.
14. The gram-formula mass of NO2 is defined as
the mass of –
A. one mole of NO2
B. one molecule of NO2
C. two moles of NO
D. two molecules of NO
Answer
A is the correct answer.
15. Given the balanced equation representing a reaction:
CaO(s) + CO2(g) →CaCO3(s) + heat
What is the total mass of CaO(s) that reacts
completely with 88 grams of CO2(g) to produce 200.
grams of CaCO3(s)?
A. 56 g
B. 88 g
C. 112 g
D. 288 g
Answer
C is the correct answer.
16. Which formula is both a molecular and an
empirical formula?
A) C6H12O6
B) C2H4O2
C) C3H8O
D) C4H8
Answer
C is the correct answer.