54.2 g N
determine the number of moles

3.87 mol N

General Formulas and Concepts:

Chemistry - Atomic Structure

Explanation:

Step 1: Define

54.2 g N

Step 2: Identify Conversions

Molar Mass of N - 14.01 g/mol

Step 3: Convert

= 3.86867 mol N

Step 4: Check

We are given 3 sig figs. Follow sig fig rules and round.

3.86867 mol N ≈ 3.87 mol N

given:

mass of na = 115 g

excess cl2

to determine:

mass of nacl produced

explanation:

given reaction is-

2na(s) + cl2(g) → 2nacl(s)

since cl2 is in excess, na will be the limiting reagent

as per the reaction stoichiometry na: nacl = 1: 1

i.e. moles of na reacted = moles of nacl formed

now, # moles of na = mass of na/atomic mass

                                  = 115 g/23 g.mol-1 = 5 moles

therefore, moles of nacl = 5

molar mass of nacl = 58 g/mol

mass of nacl = 5 moles * 58 g.mol-1 = 290 g

ans: amount of nacl produced = 290 g