3E Mass ratios

• Scheikunde
• Middelbare school
• vwo
• Leerjaar 3

Chemical calculations and reaction equations

Give the molecular formula of
phosphorus pentachloride

Give the correct name for

N​2​​O

1. dinitrogen oxide
2. nitrogen dioxide
3. dinitrogen dioxide
4. dinitrogen monoxide

Aluminium oxide ( Al2O3 ) is formed from its elements. Give the reaction equation.
Arrow: → is "ALT 26"

What is the unit for density?

1. ​cm​3​​​​g​​
2. ​g​​cm​3​​​​

How many L O2 is needed for the reaction of 5 m3 Al?
Massa ratio Al : O2 = 9 : 8

4Al+3O​2​​→2Al​2​​O​3​​

ρAl=2,7​cm​3​​​​g​​

ρO​2​​=1,43​L​​g​​

V_O₂ in L, required to let 5 m³ Al react fully into Al₂O₃. 

ρ Al = 2,7 g per cm³; ρ O₂ = 1,43 g per L; Al : O₂ = 9 : 8  

In an airbag sodium azide (NaN3 ) reacts rapidly into its elements.
Give the reaction equation.

This reaction is a:

2NaN​3​​→2Na+3N​2​​

1. combustion reaction
2. decomposition reaction
3. synthesis reaction
4. who should I know?

Calculate the amount of liters of N2 that is formed during the decomposition of 60 g NaN3.
mass ratio Na : N2 = 2 : 3,6

ρN​2​​=1,25​L​​g​​

 V = ? L nitrogen formed during the decomposition of 60 g sodium azide.

The mass ratio sodium : nitrogen = 2 : 3,6

ρN​2​​=1,25​L​​g​​

When hydrogen and nitrogen react, ammonia is formed. Give the chemical equation.

Calculate the volume% of H2 that does not react when 18 L of hydrogen reacts with 5 L of N2.
mass ratio H : N2 = 3 : 14

3H​2​​+N​2​​→2NH​3​​

ρH​2​​=0,090​L​​g​​

ρN​2​​=1,17​L​​g​​

Test next week in

Learn elements & nomenclature; 

do you assignments utai wk 3

You can expect:

• approx. 5 reaction equations (assignment week 50-51)
• approx. 8 calculations with massa ratio's, density, deficit, yield and/or percentages. (assignment week 1-3)