Question

You have 10.0 g each of Na, C, Pb, Cu and Ne. Which contains the smallest number of moles? You have 10.0 g each of Na, C, Pb, Cu and Ne. Which contains the smallest number of moles?

1. Pb
2. Cu
3. Ne
4. Na

Answer 1

Answer:

The answer to your question is number 1. Pb

Explanation:

Data

10 grams of Na, C, Pb, and Ne

Process

Calculate the moles of each element

                        23 g of Na ----------------- 1 mol

                        10 g of Na ------------------- x

                               x = 0.43 moles of Na

                        20 g of Ne ---------------- 1 mol

                        10 g of Ne ----------------- x

                               x = 0.5 moles of Ne

                         64 g of Cu -------------- 1 mol

                          10 g of Cu -------------- x

                              x = 0.16 moles of Cu

                         207 g of Pb ------------- 1 mol

                            10 g of Pb -------------- x

                               x = 0.048 moles of Pb

Pb has the smallest number of moles

Answer 2

Answer:

Pb contains the smallest no of moles

Mole = mass/atomic mass

For lead no of mole = 10g/207.2g/mol

= 0.04826mol

For Cu no of mole = 10g/63.546g/mol = 0.1574mol

For Ne no of mole = 10g/20.1797g/mol = 0.4955mol

For Na no of mole = 10g/22.9898g/mol = 0.5350mol