What is the formula mass of potassium chloride, KCl?
a)
32.3 amu
b)
74.6 amu
c)
149.2 amu
d)
154.5 amu
2.
What is the molar mass of CO2?
a)
22.0 g/mol
b)
28.0 g/mol
c)
44.0 g/mol
d)
56.0 g/mol
3.
What is the molar mass of KBr?
a)
54.0 g/mol
b)
74.1 g/mol
c)
119 g/mol
d)
1.20 X 10^24 g/mol
4.
What is a mole in chemistry terms?
a)
a mammal found in Eurasia and North America
b)
an SI unit for measuring the amount of a substance
c)
a benign tumor sometimes found on human skin appearing as a small, sometimes raised area of skin, usually with darker pigment
d)
a Mexican sauce made from chili peppers, other spices, and chocolate
5.
How many Carbon atoms are present in 1.00 mole of methane, CH4?
a)
3.01 x 10^23
b)
12.04 x 10^23
c)
6.02 x 10^23
d)
6.02 x 10^25
6.
Which would have more atoms?
a)
1 mol of Li
b)
1 mol of Au
c)
1 mol of S
d)
None, all are equal
7.
How many molecules are in 2.50 moles of H₂O?
a)
1.51 X 10²⁴ molecules of H₂O
b)
4.15 X 10²⁴ molecules of H₂O
c)
3.01 X 10²⁴ molecules of H₂O
d)
8.31 X 10²⁴ molecules of H₂O
8.
How many moles are there in 8.50 X 10²⁴ molecules of sodium sulfate, Na₂SO₃?
a)
1.40 moles
b)
14.1 moles
c)
51.2 moles
d)
5.12 X 10⁴⁸ moles
9.
What is the mass percent of carbon in glucose, C₆H₁₂O₆?
a)
25.00% C
b)
40.00% C
c)
41.40% C
d)
72.07% C
10.
A compound is found to have an empirical formula of CH₂O. What is the molecular formula when the molecular weight is 180.0 grams?
a)
C₂H₄O₂
b)
C₆H₈O₆
c)
C₆H₁₂O₆
d)
C₁₂H₂₄O₁₂
11.
What is the molar mass of carbon?
a)
6.0 g/mol
b)
12.0 g/mol
c)
22.4 g/mol
d)
6.02 X 10^23 g/mol
12.
What is the empirical formula for the compound that has 46 grams of sodium, 64 grams of sulfur, and 48 grams of oxygen?
a)
Na2S2O3
b)
Na3S2O2
c)
Na2S2O2
13.
What is the empirical formula for glucose, C6H12O6?
a)
CH2O
b)
C2H4O2
c)
C3H6O3
d)
C6H12O6
14.
What mass of sulfur would have precisely 4.7x10^22 atoms of sulfur?
a)
6.02 g sulfur
b)
4.7 g sulfur
c)
2.5 g sulfur
d)
1.3 g sulfur
15.
A student burns 1.50 mol C₃H₈ according to the following reaction:
C₃H₈ + 5O₂ → 3CO₂ + 4H₂O
How many grams of carbon dioxide are produced?
a)
4.40 x 10¹ g
b)
6.61 x 10¹ g
c)
1.32 x 10² g
d)
1.98 x 10² g
16.
Antimony is burned in oxygen to form antimony oxide.
4 Sb + 3 O₂ → 2Sb₂O₃
How many moles of Sb₂O₃ will be formed when you have 20.0 moles of oxygen gas?
a)
10.0 moles
b)
13.3 moles
c)
15.5 moles
d)
4.0 moles
17.
Potassium chlorate decomposed into potassium chloride and oxygen gas.
2KClO₃ → 2 KCl + 3O₂
How many grams of oxygen gas will be given off from 50.0 grams of potassium chlorate?
a)
9.84 grams
b)
19.7 grams
c)
33.3 grams
d)
75.0 grams
18.
Which of the following has the highest mass?
a)
50.0 g water
b)
50.0 mol NaCl
c)
50.0 molecules carbon dioxide
d)
50.0 L of oxygen at STP
แป้นคำตอบ
Chemistry 5th 6 weeks test reveiw
คำถามทั้งหมด: 18
1.
b)
74.6 amu
2.
c)
44.0 g/mol
3.
c)
119 g/mol
4.
b)
an SI unit for measuring the amount of a substance