Anions, Cations, and Ionic Reactions PDF

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This contains a lab report for the experiment (Anions, Cations, and Ionic Reactions)...

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Pedro Montes

Date of experiment: May 1, 2021

Report submitted: May 3, 2021 Title: Anions, Cations, and Ionic Reactions Purpose: The purpose of this lab is to learn how double displacement reactions and flame tests can be used to identify anions and cations. Procedure: The procedure of this lab was to start by mixing the cations and anions together, filter the solution you have and collect precipitate. Weigh precipitate and write down all data and observations that occurred.

Exercise 1: Qualitative Anion Tests Data Table 1: Anion Confirmation Tests Chemical

Anion

Addition of AgNO 3

Addition of HCI

NaBr

Bromide

Color became a cloudy white

Became less white/cloudy

Na2CO3

Carbonate

Cloudy white with swirls

Bubbles formed but still cloudy white

NaCI

Chloride

Cloudy white at the bottom but clear at the top

No change. Stayed the same reaction

NaI

Iodine

Color change to greenish/blue with swirls

The swirls began separating into blobs

Na2SO4

Sulfate

Clear with no change

Cloudy and white

Na2

Sulfide

Turned brown when the drop hit

Brown color separated into flakes

Unknown #103

Carbonate

Color change to cloudy white

Still cloudy white with bubbles forming

Unknown #104

Sulfide

Color change to brown

Brown separated into flakes

Exercise 2: Qualitative Cation Tests - Flame Data Table 2: Cation Flame Tests

Pedro Montes

Date of experiment: May 1, 2021

Chemical

Cation

Flame Observations

KI

Potassium

Light pink

CaCl2

Calcium

Red

LiOH

Lithium

Bright pink

NaCI

Sodium

Orange

Cu(NO3)2

Copper

Teal

Unknown #105

Copper

Teal

Unknown #106

Potassium

Light pink

Unknown #107

Calcium

Red

Data Table 3: Complete Chemical Identification Complete Chemical Name and Formula

Chemical

Cation

Anion Test observations

Anion

Unknown #105

Copper

Using AgNo 3 : No change

No3^2-

Copper(III) nitrate, Cu(NO3)2

Unknown #106

Potassium

Using AgNo 3: Brown in the middle and white fading towards the middle

I-

Potassium iodine, KI

Unknown #107

Calcium

Using AgNo 3: Color turned white and cloudy

CI-

Calcium Chloride, CaCl2

Questions Part 1: A- What was the identity of the anion in Unknown #103? Explain How Used The observations recorded in Data Table 1 to reach this conclusion. ●

Carbonate because it had the same reaction when adding AgNO3 and then again when adding HCI

B- What was the identity of the anion in Unknown #104? Explain how you used the observations recorded in Data Table 1 to reach this conclusion.

Pedro Montes ●

Date of experiment: May 1, 2021

Sulfide because it had the same reaction when adding AgNO3 and again when adding HCI.

C- Write the chemical equation for ionic reaction between Na2S and AgNO 3. ● Na2S+ AgNO3 ➝ Ag2S + NaNO3 D- Write the chemical equation for ionic reaction between NaBr and AgNO 3. ● NaBr + AgNO3 NaNO3 + AgBr E- Use your results and observations in Data Table 1 to create a flowchart for identification of unknown anions, using the AgNO 3 and HCl confirmation tests. Insert the flowchart below.

Questions Part 2: A- What was the identity of the cation Unknown#105? Explain How Used The observations recorded in Data Table 1 to reach this conclusion. ●

In order to identify the cation unknown #105 I used the flame test. The color changed to teal just like Copper did in Table 2.

Pedro Montes

Date of experiment: May 1, 2021

B- Use your results and observations in Data Tables 1, 2, and 3, to create a flowchart for the identification of an unknown (both an unknown anion and cation), using the AgNO 3 and HCl confirmation tests and the cation flame tests.

C-If you were asked to confirm the identity of an unknown chemical as lithium sulfide (Li2S), describe the tests that you would use to confirm the identity. Use your results in both Exercise 1 and Exercise 2 to describe the observations in both the cation and anion tests that would allow the unknown to be confirmed as lithium sulfide. ● I would take a sample of Li2S and do the flame test. A bright pink color confirms the presence of Li+. I would then confirm the presence of S2- by adding AgNo3 to see if it turns brown and if it does there is a high chance that there is Sulfide.

Conclusion: Overall, the lab was interesting and fun to perform. I enjoyed watching the reactions when adding AgNO3 and HCI to the chemicals and seeing how they reacted. I learned more about cations and anions and how they work. In general this was a good lab....