30.0 g CuO + 20.0 g CH4 can produce a maximum of __?__ g Cu.�4 CuO + CH4 „_ 2 H2O + 4 Cu + CO2

To determine the maximum amount of Cu that can be produced, we need to calculate the limiting reactant.

1. Start by converting the given masses of CuO and CH4 to moles using their respective molar masses.
- The molar mass of CuO (copper(II) oxide) is 63.55 g/mol (atomic mass of Cu = 63.55 g/mol and atomic mass of O = 16.00 g/mol).
- The molar mass of CH4 (methane) is 16.04 g/mol (atomic mass of C = 12.01 g/mol and atomic mass of H = 1.01 g/mol).
- Moles of CuO: 30.0 g CuO / 63.55 g/mol = 0.472 mol CuO
- Moles of CH4: 20.0 g CH4 / 16.04 g/mol = 1.246 mol CH4

2. Next, find the stoichiometric ratio between CuO and Cu. According to the balanced chemical equation, 4 moles of CuO react to form 4 moles of Cu.
- The ratio is 1:1. For every 1 mole of CuO, we get 1 mole of Cu.

3. Compare the number of moles of CuO to the number of moles of CH4, keeping in mind the stoichiometric ratio.
- The ratio is 1:1, so we compare the same number of moles in both compounds.
- Moles of CuO: 0.472 mol
- Moles of CH4: 1.246 mol

4. The limiting reactant is the one that will run out first. In this case, CuO and CH4 have a 1:1 stoichiometric ratio, so the limiting reactant is CuO because it has the smaller number of moles.

5. Calculate the maximum amount of Cu that can be produced using the amount of the limiting reactant (CuO).
- The stoichiometric ratio shows that 1 mole of CuO produces 1 mole of Cu.
- Moles of Cu produced = Moles of CuO = 0.472 mol
- Mass of Cu produced = Moles of Cu produced × molar mass of Cu
= 0.472 mol × 63.55 g/mol = 29.98 g

Therefore, the maximum amount of Cu that can be produced is 29.98 g.

Here is a worked example of a stoichiometry problem.

http://www.jiskha.com/science/chemistry/stoichiometry.html