Download No Calculator Questions #1 – FUN!

Chemistry 11 HL
Unit 2 / IB Topics 1.1 and 1.2
No Calculator Questions #1 – FUN!
TIPS:
1. Round molar masses to whole numbers.
2. Use 6 x 10
23
for Avogadro’s number.
3. Think in fractions and reduce to the lowest value before converting to a decimal.
4. Know a few molar mass values by heart:
H2
H 2O
O2
CO2
22
N2
1.
What amount of hydrogen gas, in moles, contains 1.8 x 10
molecules?
2.
Calculate the number of moles in 8.0 g of sodium hydroxide.
3.
Calculate the mass of 3.0 x 10 mol of magnesium oxide.
4.
What amount of calcium oxide (CaO) contains 16 mg of calcium?
5.
What amount (in moles) is present in 2.0 g of sodium hydroxide, NaOH?
6.
How many atoms of nitrogen are present in 0.50 mol of sodium azide, NaN3, the chemical
found in air bags of automobiles?
7.
What is the mass of 1.8 x 10
-2
20
molecules of carbon dioxide?
Chemistry 11 HL
Unit 2 / IB Topics 1.1 and 1.2
15
8.
How many milligrams of iron contains 4.8 x 10
9.
What mass of potassium chlorate, KClO3, contains 9.6 g of oxygen?
10.
What mass of sodium hydroxide, NaOH, contains 3.0 x 10
11.
Which sample contains the greatest number of molecules?
a)
12.
3.6 g H2O
3.2 g O2
c)
atoms of sodium?
3.6 g H2O
d) 2.2 g CO2
b)
2.2 g CO2
c) 1.0 g CaCO3
d) 2.4 g MgSO4
Which sample contains the same number of ions as the value of Avogadro’s constant?
a) 0.5 mol KBr
14.
b)
20
Which sample contains the least number of oxygen atoms?
a)
13.
4.0 g H2
atoms?
b) 0.5 mol CaBr2
c) 1.0 mol CaO
d) 1.0 mol K2O
Which sample has the greatest mass?
a) 1 mol of Na2S
b) 3.0 x 10
24
d) 1.2 x 10 atoms of K
ANSWERS
1. 0.030 mol
5. 0.050 mol
9. 24.6 g
11. A
24
2. 0.20 mol
23
6. 9.0 x 10 N atoms
10. 0.020 g
12. C
1
molecules of O2
c) 8.8 x 10 g of NaCl
3. 1.2 g
7. 0.013 g
4.
–4
8. 4.5 x 10 mg
13. A
14. B