Embed Size (px)
DESCRIPTION
chemistry question bank
Citation preview
Chapter 2
1. a) Atom
Number of protonsBilangan proton
Number of neutronsBilangan neutron
S 16 17T 16 18U 17 18V 18 17
Table 1
Table 1 shows the number of protons and neutrons of three atoms. Jadual 1 menunjukkan bilangan proton dan neutrons bagi tiga atom.(i) What is meant by the proton number and nucleon number of an atom? Apakah yang dimaksudkan dengan nombor proton dan nombor nukleon bagi atom? Proton number Nombor proton … … … … … … … … … … … … … … … … … … … … … … … … … … … … …
[1 mark] Nucleon number Nombor nucleon … … … … … … … … … … … … … … … … … … … … … … … … … … … … …
[1 mark](ii) Represent atom S in the form of A
Z X
Tuliskan atom S dengan perwakilan atom unsur AZ X
… … … … … … … … … … … … … … … … … … … … … … … … … … … … …[1 mark]
(iii) Which of the atoms are isotopes? Atom-atom yang manakah isotop? … … … … … … … … … … … … … … … … … … … … … … … … … … … … …
[1 mark] (iv) State a reason for your answer in (d)(i)
Nyatakan alasan bagi jawapan anda di (d)(i)… … … … … … … … … … … … … … … … … … … … … … … … … … … … …
[1 mark]
(b) An organic compound Q consists of 64.87% of carbon, 13.51% of hydrogen and 21.62% of oxygen.
[Relative atomic mass: H,1 ; C,12 ;O, 16]Suatu sebatian organik Q mengandungi karbon 64.87%, hidrogen 13.51% dan oksigen 21.62%.[Jisim atom relatif: H,1 ; C,12 ; O, 16]
(i) Determine the empirical formula of compound Q.Tentukan formula empirik bagi sebatian Q.
[3 marks] (ii) If the relative molecular mass of compound Q is 74, find the molecular formula of compound Q.
Jika jisim molekul relatif bagi sebatian Q adalah 74, cari formula molekul bagi sebatian Q.
[2 marks]
2. Graph 2.1 shows the temperature against time when solid naphthalene is heated.
Graph 2.1
(a) State the melting point of naphthalene.
........................................................................................................................
[ 1 mark](b) What is the physical state of naphthalene at:
(i) PQ
........................................................................................................................
(ii) RS
........................................................................................................................[ 2 marks]
(c) Explain why there is no change in temperature from Q to R.
..............................................................................................................................
..............................................................................................................................[ 2 marks]
(d) State how the movement of naphthalene particles changes between R and S during heating.
… … … … … … … … … … … … … … … … … … … … … … … … … … … … … … ............[ 1 mark]
Temperature / 0C
Time/s
T1
T0 P
Q R
S
(e) Table 2.2 shows four substances and their respective formulae.
Substances Chemical formula
Iodin I2
Copper CuNaphthalene C10H8
Copper(II) sulphate CuSO4
Table 2.2
Use information from table 2.2 to answer the following questions.
(i) State one substance which exist as a molecule.
.......................................................................................................................[ 1 mark]
(ii) Which substance can conduct electricity in the solid state?
........................................................................................................................[ 1 mark]
(iii) What type of particle presents in copper(II) sulphate?
........................................................................................................................[ 1 mark]
(f) A few drops of liquid bromine are dropped into a gas jar. The brown bromine vapour spreads to the upper part of the gas jar. The time taken is very short.Name the process occurs.
… … … … … … … … … … … … … … … … … … … … … … … … … … … … … ................[ 1 mark]
1 Table 1 shows the melting point and boiling point of four substances.
Substances Melting point/ ºC Boiling point/ ºCP -5 67Q -105 -38R 80 140S 801 1413
TABLE 1
(a) What is the physical state of P and S at room temperature? P: ....................................................................................................................
S: .................................................................................................................... [2 marks]
(b) Draw the arrangement of particles of P at room temperature.
[1 mark]
(c) Explain why substance Q has a low melting point and boiling point.
............................................................................................................................
............................................................................................................................
. ............................................................................................................................
............................................................................................................................ [2 marks]
(d) Draw the set up of apparatus to determine the melting point of substance R.
[2 marks]
(e) Sketch the graph of temperature against time for substance R when it is heated from room temperature until it reaches a temperature of 100oC.
[2 marks]
