Oxidation numbers
Balancing Chem Equations
Easy Stoichiometry
Hard Stoichiometry
Miscellaneous
100

P4 (Oxidation number of P)

0

100

N+ H2 🡢 N2H4

N+ 2 H2 🡢 N2H4

100

How many molecules of O2 are needed when 38 atoms of S react?

2 S + 3 O2 🡢 2 SO3

57 molecules O2

100

What mass of H2O is produced by the combustion of 1.00 mol of CH4?

CH4 + 2 O2 🡢 CO2 + 2 H2O

36.0 g H2O

100

What type of reaction is this?

2 KClO3 → 2 KCl + 3 O2

What is Decomposition?

200

SO2 (Oxidation number of S)

+4

200

Al + O2 🡢 Al2O3

4 Al + 3 O2 🡢 2 Al2O3

200

How many moles of Ag are produced when 0.661 mol of Al are reacted?

Al + 3 Ag+ 🡢 Al3+ + 3 Ag

1.98 mol Ag

200

What mass of NaHCO3 is needed to produce 2.659 mol of CO2?

2 NaHCO3 🡢 Na2CO3 + H2O + CO2

322 g HgO

200

Which element is oxidized in this redox reaction?

2 Ni + 3 I2 🡢 2 NiI3

Nickel is oxidized

300

NO2- (Oxidation number of N)

+3

300

NaClO3 🡢 NaCl + O2

2 NaClO3 🡢 2 NaCl + 3 O2

300

How many molecules are present in 2.509 mol of H2S? 

1.511 x 1024 molecules H2S

300

How many moles of Al can be produced from 10.87 g of Ag?

Al(NO3)3 + 3 Ag 🡢 Al + 3 AgNO3

0.0504 mol Al

300

How many moles are present in 54.6 mL of mercury if the density of mercury is 13.6 g/mL?

3.72 mol Hg

400

Li2O2 (Oxidation number of Li)

+1

400

C3H8 + O2 🡢 CO2 + H2O

C3H8 + O2 🡢 3 CO2 + 4 H2O

400

What is the mass of 0.311 mol of Xe?

40.8 g Xe

400

What mass of Fe is generated when 100.0 g of Al are reacted?

Fe2O3 + 2 Al 🡢 2 Fe + Al2O3

207.0 g Fe

400

A chemist combusts a 3.009 g sample of C5H12 and obtains 3.774 g of H2O. What is the theoretical yield?

4.509 g H2O

500

Ca(NO3)2 (Oxidation number of N)

+5

500

Mg(OH)2 + HNO3 🡢 Mg(NO3)2 + H2O

Mg(OH)2 + 2 HNO3 🡢 Mg(NO3)2 + 2 H2O

500

How many moles are present in 48.8 g of BaCO3?

0.247 mol BaCO3

500

What mass of PbSO4 is produced when 29.6 g of H2SO4 are reacted?

Pb + PbO2 + 2 H2SO4 🡢 2 PbSO4 + 2 H2O

91.5 g PbSO4

500

Acetylene (C2H2) is formed by reacting 7.08 g of C and 4.92 g of H2.

2 C + H2 🡢 C2H2

What is the limiting reagent?

C is the limiting reagent