Question

part 2 calculations with the mole (points listed on each question—33 points total)
consider the following balanced reaction and answer the questions: ( 2 mathrm{nabr}+mathrm{cl}_{2} \to 2 mathrm{nacl}+mathrm{br}_{2} )

1. list all the stoichiometric ratios (also called molar ratios) for ( mathrm{nabr} )? (3 pts)

( mathrm{nabr} / mathrm{cl}_{2} )
( mathrm{nabr} / mathrm{nacl} )
( mathrm{nabr} / mathrm{br}_{2} )

1. what is the stoichiometric ratio of moles of ( mathrm{cl}_{2} ) versus moles of ( mathrm{br}_{2} )? (1 pts)
2. what is the molar mass of ( mathrm{nabr} )? express your answer to the ( 100^{\text {th }} ) decimal place. (3 pts)
3. what resource did you use to calculate the molar mass? (1 pt)

Explanation:

Step1: Determine stoichiometric ratio for Cl₂ and Br₂

From the balanced equation \(2NaBr + Cl_{2}\to2NaCl + Br_{2}\), the coefficients of \(Cl_{2}\) and \(Br_{2}\) are 1 and 1 respectively. So the ratio \(Cl_{2}/Br_{2}=\frac{1}{1}\)

Step2: Calculate molar mass of NaBr

The atomic mass of \(Na\) is \(22.99\space g/mol\) and \(Br\) is \(79.90\space g/mol\). Using the formula \(M = M_{Na}+M_{Br}\), we have \(M = 22.99 + 79.90=102.89\space g/mol\)

Answer:

1. \(1:1\)
2. \(102.89\space g/mol\)
3. Periodic table (to obtain atomic masses of \(Na\) and \(Br\))