2. How many moles are found in 3.2 x 1023 atoms of NaCl?

0.53 mol NaCl

General Formulas and Concepts:

Chemistry - Atomic Structure

Explanation:

Step 1: Define

3.2 × 10²³ atoms NaCl

Step 2: Identify Conversions

Avogadro's number

Step 3: Convert

= 0.531385 mol NaCl

Step 4: Check

We are given 2 sig figs. Follow sig fig rules and round.

0.531385 mol NaCl ≈ 0.53 mol NaCl

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

metric time was an attempt to create a standard unit of time based off of 10, but it never took off an is not included in the metric system (si)