Group 7 Flashcards
Give the products of this equation:
NaCl (s) + H2SO4 (aq) —>
NaHSO4 (s) + HCl (g)
State the observation for this reaction:
NaCl (s) + H2SO4 (aq) —> NaHSO4 (s) + HCl (g)
Steamy Fumes
Give the half equation for the oxidation of bromide ions?
2Br- —> Br2 + 2e-
What are the observed when bromide ions react with sulphuric acid in a redox reaction?
Acidic Gas (SO2)
Brown Fumes (Br2)
State the 3 different sulphur products that can be formed with iodide ions reacts with H2SO4?
Sulphur Dioxide (SO2)
Sulphur (S)
Hydrogen Sulphide (H2S)
What is the observation when iodine is formed in a reaction with H2SO4?
Black solid
The student noticed some of the liquid injected into a gas syringe didn’t vaporise. Explain the effect this has on the Mr calculated by the student?
Lower volume recorded so Mr increases
What’s the observation of:
- H2S
- S
- SO2
- Bad-Egg Smell
- Yellow Solid
- Acidic Gas
What is the test for halide ions?
Why is this needed?
Acidified Silver Nitrate (AgNO3)
To remove carbonate ions
What is observed when dilute ammonia (NH3) is added to AgCl?
White precipitate dissolves
What is observed when dilute ammonia (NH3) is added to AgBr?
Cream precipitate remains
What is observed when concentrated ammonia (NH3) is added to AgBr?
Cream precipitate dissolves
What is observed when concentrated ammonia (NH3) is added to AgI?
Yellow precipitate remains
Why is chlorine added to drinking water?
To kill bacteria
Cl2 (g) + H2O (l)
<—> HClO (aq) + HCl (aq)
Cl2 (g) + H2O (g) —>
HCl + O2 ——> balance
Cl2 (g) + 2NaOH (aq) —>
NaClO + NaCl + H2O
Chlorine is toxic. Why is it not dangerous to add it to drinking water?
Not toxic once added in low concentrations
State the observation for:
Cl2 + 2NaBr —> Br2 + 2NaCl
Orange/Brown solution
State the observation for:
Cl2 + 2NaI —> I2 + 2NaCl
Brown solution
State the observation for:
I2 + 2NaCl —>
No reaction (brown solution remains)
Cl2 + NaBr —>
Br2 + 2NaCl
What is the observation when sodium carbonate is added to an acid?
Effervescence (CO2 gas is released)
What is the reagent used to test for ammonium ions?
Heat with NaOH
What is observed when ammonium (NH4+) ions are heated with NaOH?
Gas released turns damp red litmus paper blue
What gas is released when ammonium ions are warmed with NaOH?
Ammonia Gas (NH3)
Outline a logical sequence of test-tube reactions for sodium carbonate, sodium fluoride and sodium chloride that the student could carry out to identify each of these compounds.
Include the observations the student would expect to make.
Give equations, including state symbols, for any reactions that would take place. (6)
Stage 1 - suggested tests:
1a Add nitric acid to all 3
1b Add water / make into a solution
1c Add AgNO3
Stage 2 - expected observations:
2a Sodium Carbonate will fizz with acid
2b NaCl gives white ppt with AgNO3
2c NaF shows no (visible) change
Stage 3 Equations – state symbols must match method
3a Na2CO3 + 2HNO3 → 2NaNO3 + CO2 + H2O
3b AgNO3 + NaCl → AgCl + NaNO3
3c correct state symbols
State and explain how the rate of reaction for 1-bromobutane compares with 1-iodobutane?
Predict how the graph of RoR would differ?
Decrease as C-Br bond is stronger than C-I
Line for 1-bromobutane will be below 1-iodobutane
What’s an oxidising agent?
Electron acceptor
What’s a reducing agent?
Electron donor
Way to remember oxidation state order?
Ionic equation to show AgCl dissolves when diluted ammonia is added?
AgCl(s) + 2NH3(aq) —-> Ag(NH3)2+(aq) + Cl-(aq)
Ionic equation to show AgBr is insoluble when diluted ammonia is added?
AgBr(s) + 2NH3(aq) —-> Ag(NH3)2+(aq) + Br-(aq)
Equation for extraction of Ti in TiCl4?
TiCl4 + 2Mg —-> 2MgCl2 + Ti
