Download Chapter-3 Mole-Mass Calculations

Calculations: Moles, Mass, and Particles
Give the number of moles of atoms and the total mass in grams represented by each of the following
compounds.
1) HCl
6) 0.10 mol H2O
2) H2SO4
7) 0.50 mol CaCO3
3) 2Na2CO3
8) 0.30 mol H3PO4
4) 3Ca(OH)2
9) 1.50 mol NaCl
5) 4CuSO4  5H2O
10) 0.0010 mol H2SO4
Convert to the equivalent number of molecules for each of the following compounds.
1) 72 grams HCl
4) 500 grams NO
2) 9.0 grams H2O
5) 1.00 gram CCl4
3) 22 grams CO2
Convert to mass in grams.
6) 6.02 x 1021 molecules Cl2
7. 3.01 x 1023 molecules SO2
8) 1.81 x 1024 molecules CO2
9. 1000 molecules H2S
10) 15 g NaOH equals what equivalent mass of H2SO4?
11) 71.68 L of H2 equals what equivalent mass of Pb(NO3)2?
12) In the reaction between cobalt and sulfur to form cobalt sulfide, Co + S  CoS, 16.5 g Co reacts
with what equivalent mass of S?
13) What is the mass of 7.50 moles of sulfur dioxide (SO2)?
Ans: 481 g
14) What is the mass of 0.438 mole of ammonium chloride (NH4Cl)?
Ans: 23.4 g
15) How many moles are there in 250.0 g of sodium phosphate (Na3PO4)? Ans: 1.524 mol
16) How many moles are there in 993.6 g of potassium sulfate (K2SO4)?
1
Ans: 5.70 mol
17) How many atoms are there in 3.00 moles of sodium (Na)?
Ans: 1.81 x 1024 atoms
18) How many atoms are there in 1.638 x 10-9 mole of lithium (Li)?
Ans: 9.86 x 1014 atoms
19) How many molecules are there in 4.55 moles of nitrogen (N2)?
Ans: 2.74 x 1024 molecules
20) How many atoms of nitrogen (N) are there in 2.18 moles of nitrogen (N2)?
Ans: 2.62 x 1024 atoms
21) How many atoms are there in 0.663 mole of water (H2O)?
Ans: 1.2 x 1024 atoms
22) How many moles are there in 15.5 x 1023 molecules of carbon dioxide (CO2)?
Ans: 2.57 mol
23) How many moles are there in 1.326 x 1012 molecules of carbon tetrachloride (CCl4)?
Ans: 2.2 x 10-12 mol
24) What is the volume occupied by 4.20 moles of oxygen gas (O2) at STP?
Ans: 94.1 dm3
25) What volume does 0.0147 mole of nitrogen dioxide gas (NO2) occupy at STP?
Ans: 0.329 L
26) How many moles are there in 45.0 dm3 of methane gas (CH4) measured at STP?
Ans: 2.01 mol
27) How many moles are there in 0.335 dm3 of argon gas (Ar) at STP?
Ans: 1.5 x 10-2 mol
28) A sample of silver weighing 250 mg completely melts after absorbing 6.625 cal of heat. Calculate
the heat of fusion (Hf) in cal/g, J/g, J/mol, and kJ/ mole for silver.
a) 26.5 cal/g
b) 111.3 J/g
c) 1.2 x 104 J/mol
d) 12.0 kJ/mol
29) Calculate the following for the hydrate, Zn3(PO4)2∙4H2O
a) the mass of one mole of hydrate
b) the total number of hydrogen atoms in one molecule
c) the total number of oxygen atoms in one molecule
d) the total number of atoms in one mole of hydrate
e) the total number of moles of zinc in one mole of hydrate
f) the total number of moles of water in one mole of hydrate
g) the total number of water molecules in one mole of hydrate
2
Ans. 458 g/mol
Ans. 8
Ans. 12
Ans. 1.5 x 1025
Ans. 3
Ans. 4
Ans. 2.41 x 1024
3