Atomic structure

Question 1

What are the charges of each group in the Periodic table?

Answer 1

1 = +1
2 = +2
3 = +3
5 = -3
6 = -2
7 = -1

Question 2

What is the definition and appearance of a solution?

Answer 2

A mixture containing a solute dissolved in a solvent - transparent

Question 3

What is the definition and appearance of a precipitate?

Answer 3

Aqueous ions react together in aqueous solution to form a solid precipitate - opaque, solid substance

Question 4

What is the definition of effervesence?

Answer 4

The release of gas from an aqueous solution

Question 5

What should you say instead of “no visible change” while making an observation?

Answer 5

Stayed the same e.g. solution remained colourless

Question 6

What is the formula for calculating relative atomic mass?

Answer 6

(mass of isotope A x % abundance) + (mass of isotope B x % abundance) / 100

Question 7

What is the definition of relative isotopic mass?

Answer 7

The mass of an atom of an isotope compared with 1/12 of the mass of an atom of Carbon-12

Question 8

What is the definition of relative atomic mass?

Answer 8

The weighted mean mass of an atom of an element compared with 1/12 of the mass of an atom of Carbon-12

Question 9

What are the charges on zinc and silver ions?

Answer 9

Zn2+ and Ag+

Question 10

What are the ions of ammonium, hydroxide, nitrate, carbonate, sulfate and phosphate (polyatomic ions)?

Answer 10

NH4(+) 
OH(-)
NO3(-)
CO3(2-)
SO4(2-)
PO4(3-)

Question 11

What would the charges be on a Cu (ii) ion and an Fe (iii) ion?

Answer 11

Cu (ii) = 2+

Fe (iii) = 3+

Question 12

How are binary (2 elements) compounds named?

Answer 12

Ending of the non-metal changed to -ide e.g. sodium chloride UNLESS it contains OXYGEN which means the ending would be -ate

Question 13

How do you write formulae for ionic compounds?

Answer 13

Balance the charges on both ions

e.g. sodium oxide would be Na2O as Na has a + charge and O has a 2- charge

Question 14

What is the chemical formula for iron (ii) nitrate?

Answer 14

Fe(NO3)2

Question 15

What must you always do when writing ionic equations?

Answer 15

Include state symbols

Question 16

What do ionic equations show?

Answer 16

The particular species that changes

e.g. AgNO3 + KBr –> AgBr (s) + KNO3 (aq)

AgBr is the precipitate so only Ag and Br are needed

Ag+ (aq) + Br- (aq) –> AgBr (s)

Question 17

What type of reaction is Ag+ (aq) + Br- (aq) –> AgBr (s)?

Answer 17

Precipitation reaction

Question 18

What do half equations show?

Answer 18

The loss/gain of electrons

e.g. Na –> Na+ + e-

Question 19

Which compounds are all white and insoluble in solution?

Answer 19

BaCO3, Ag2CO3 and Ag2SO4

Question 20

What is the correct sequence of tests?

Answer 20

1. Carbonate test (removes carbonate ions)
2. Sulfate test (removes sulfate ions)
3. Chloride test

Question 21

What would happen if you did the sulfate test first?

Answer 21

You would get 2 different white precipitates

1. Ba(2+) + SO4(2-) –> BaSO4 (s)
2. Ba(2+) + CO3(2-) –> BaCO3 (s)

Question 22

What would happen if you did the chloride test first?

Answer 22

You could get 3 different white precipitates

1. Ag+ + Cl- –> AgCl (s)
2. 2Ag+ + SO4(2-) –> Ag2SO4 (s)
3. 2Ag+ + CO3(2-) –> Ag2CO3 (s)

Question 23

Which reagent is used to remove carbonate ions?

Answer 23

Nitric acid

Question 24

Which reagent is used to remove sulfate ions?

Answer 24

Barium nitrate

Question 25

Which reagent is used to remove chloride ions?

Answer 25

Silver nitrate

Question 26

Which reagent is used to remove ammonium ions?

Answer 26

Sodium hydroxide + heat