Download CHEMISTRY 11 Unit 4 Assignment - The Mole

CHEMISTRY 11
Unit 4 Assignment – The Mole
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1. Convert 9.8 x 1024 molecules of C2H6 to grams. (2)
2. The mass of an unknown gas is 11.59 g. The mass of an equal volume of He is 1.45 g. Calculate
the molar mass of the unknown gas. (2)
3. Calculate the percentage composition of sulphur in Al2(SO4)3. (2)
4. Calculate the molar mass of Co2(SO4)3•6H2O (1)
5. The empirical formula for a compound is C2H5O and its molecular mass is 135 g/mol.
Determine the molecular formula. (2)
6. A compound is 24.4% Ca, 17.1% N and 58.5% 0. Calculate the empirical formula. (2)
CHEMISTRY 11
Unit 4 Assignment – The Mole
7. Find the number of atoms in 7.6 g of sodium phosphide. (2)
8. How many C atoms in 60.5 g of sucrose? C12H22O11 molar mass = 342.34 g/mol (2)
9. If 3.75 x 1024 atoms of hydrogen are found in a sample of ammonium chloride, what mass of
ammonium chloride is present? NH4Cl
10. How many molecules in
a) 7.56 g of bromine gas. (2)
b) 88.55g of carbon monoxide gas. (2)
c) 18.6L of chlorine gas (at STP) (2)
molar mass= 53.50 g/mol
(2)
CHEMISTRY 11
Unit 4 Assignment – The Mole
d) 1.56 x 103 L of methane gas at STP. (2)
11. What volume at STP would
a) 6.85 x 1022 molecules of sulphur dioxide take up. (2)
b) 68.7 g of helium take up. (2)
c) 1.78 mol of mercury gas take up. (2)
d) 7.51 x 10 25 molecules of nitrogen gas take up (2)
12. a) How much would 3.42 x 103L of oxygen (held at STP) weigh? (2)
CHEMISTRY 11
Unit 4 Assignment – The Mole
b) How many atoms of oxygen would be found in the above quantity of gas. (2)
13. How much mass and volume (at STP) of gaseous tetraphosphorus hexaoxide would be present
if 9.63 x 1024 atoms of oxygen were found in the sample? (4)
14. If the mass of a stone is 2.603 kg, and that of a pencil is 5.15 g, calculate the mass of the stone
relative to that of the pencil. (1)
15. If the mass of a lithium atom is 6.94 amu, and that of a uranium atom is 238.1 amu, calculate
the mass of the lithium atom relative to that of the uranium atom. (1)
16. Calculate the number of fluorine atoms in 4.25 moles of fluorine gas. (2)
17. a) Calculate the number of moles of methane in 8.71 x 1022 molecules of methane. (2)
CHEMISTRY 11
Unit 4 Assignment – The Mole
b) Calculate the number of atoms of hydrogen present in this same sample of methane. (1)
c) Calculate the number of moles of hydrogen atoms present in the sample. (1)
18. How many moles are present in 288.9 g of sodium carbonate, Na2CO3? (2)
19. What mass of Fe(NO3)2 is present in 0.0157 mole of this substance?
(2)
20. What is the molarity of a solution made by adding to 295.6 g of potassium sulfide, K 2S,
sufficient water to make 10.00 L of solution? (2)