GCSE COMBINED SCIENCE HIGHER: CHEMISTRY 2019 PAPER 1

Notes:

Question 1)

1.1  Ca, Mg, Zn, Cu

1.2   Concentration

mass

1.3  the type of element

1.4 Berrylium is less reactive

reason - the greater attraction between the nucleus and outer electrons 

1.5  50 / 1000 = 0.05

0.05 / 3.2 = 64

answer: 64

Question 2)

2.1   (aq)

2.2  HNO3

2.3  colour in nitric acid - red

colour in ammonia solution - purple

2.4    D

2.5    3 x 16 = 48

48/80 x 100 = 60

answer: 60

2.6

Question 3)

3.1

3.2  ( 800 - 300) = 500 (kJ)

answer: 500

3.3 look at the answers

3.4  (4 x 463) + (2 x 138) 

( 1,852 + 496) = 2348

( 2128 - 2348) = - 220

answer: (-) 220 (KJ)

Question 4 )

4.1 atomic weight

4.2  left gaps

4.3  weak forces between the molecules.

so little energy is required to break the forces between molecules.

4.4  The molecules get larger going down the group 

So the forces between the molecules increases 

4.5 2,8

2 in the first shell

8 in the second shell

4.6   1/40 x 6.02 x 10 to the power of 23

Question 5 ) 

5.1 metal is too reactive to be extracted using carbon

5.2     1)  aluminium oxide

2)  cryolite

5.3   Half equation at negative electrode 

Cu 2+   + 2e-   ---> Cu

half equation at positive electrode 

2 CI-   ---> Cl 2 + 2e-

5.4    1) Volume of the solution was different

2)  copper removed when drying electrode

5.5  (1.8 / 10) = 0.18

0.18 x 24 x 60

0.18 x 1440 

answer: 259 mg

5.6   4.75

5.7    2.0 / 10  = 0.2

0.2g/hour 

Question 6)

6.1   2 Na + Cl2  ----> 2NaCl

6.2  Before reaction - silver solid

during reaction - yellow flame

After reaction - white solid

6.3  Sodium has fewer energy levels.

The outer electron is closer to the nucleu.s

So greater attraction between nucleus and outer electron. 

So an outer electron is less easily lost.

6.4 

my answers: