EXPERIMENTAL PROBLEM n. 09 GROUP B

You have a given amount of sodium chloride (3,0 grams) in a small test tube. Your task is to put, in a second empty test tube, as many ions of potassium and chloride as they are in the 3,0 grams of NaCl, and then to compare the volumes of the two amounts of solids. You have also alcohol, cylinder and pipette.

1. Useful knowledge (reference data, concepts and principles)

first: m.a Na=22,99

second: m.a Cl= 35.45

third: Salts don't dissolve in alcohol

fourth: 3.0g of sodium chloride

2. Main idea

 you found the proportional number of ions in sodium chloride, after you calcolate the grams of potassium and chloride

you weigh tests tube containing the sodium chloride and potassium and chloride,at the same time you put in two beker some alcohol, so you put in each beker the different compounds and you found the volume 

3. Planning

1.You found the proportional number of ions in sodium chloride

2.you found the grams of potassium and chloride

3.you weigh tests tube

4.you put in two beker some alcohol

5.you put the containing of tests tube in the beker

6.you found the volume of comppunds

STRUMENTS: -test tube;- beker;- alcohol;- balance

4.  Report

Description of the experiment,

raw data and measures (without calculations),

relevant detailed observations

pictures and descriptions of the most important stages of the experiment

drawbacks: solutions and planning changes

5. Elaborazione e Interpretazione

Data elaboration-calculation from raw data

deductions and interpretations from calculated data

conclusions: answering problem request. Other outcomes.

Questions & Answers

1. Question 1

Why is the amount of KCl more than three grams?

because the atoms of K are as more big than atoms of sodium

2. Question 2

What data you need to calculate volumes from masses, without measuring?

to mesure volumes from masses you need weight and density

3. Question 3

Why are the volumes of the two salts so different?

4. Question 4

Why is a potassium ion bigger than a sodium ion?

Answer 4

5. Question 5

Which is the largest between:

a) a bromide ion and a chloride ion

b) a cesium ion and a cesium atom

c) a sodium ion and a magnesium ion

d) a iodine atom and a iodide ion

e) an oxygen atom and a sulphur atom