What is the meaning of isotopes?
The proton number of atom R is 14 and its relative atomic mass is 28. Which statement is correct?
What are the reactants in this equation?
Cu(OH)2 + 2HNO3 → Cu(NO3)2 + 2H2O
Element M and element L are located in Group 1 and Group 17 respectively. Element M react with element L to form a compund.
Element J and element Q have proton number of 12 and 9 respectively.
What is the relative formula mass(RAM) of a compound formed between J and Q?
(RAM: J=24; Q=19)
An oxide of element X has the empirical formula of X2O. 2.24 g of element X reacts completely with 0.96 g of oxygen. What is the relative atomic mass(RAM) of X?
Equation: 2H2O2 →> 2H2o + O2
What is the volume of O2 produced from the decomposition of 500cm3 of 2 mol dm-3 hydrogen peroxide at standard temperature and pressure(STP)?
(Molar volume of gas at STP = 22.4 dm-3 mol-1 )
Metal X has the following properties.
-Less reactive than iron
-Does not react with iron(II) oxide
Which metal oxide can react with X?
Which statement explains why the reactivity of Group 1 elements when going down the group?
Some transition elements and their compounds are useful catalysts in industry. Which pair is correct?
How does a catalyst increase the rate of reaction?
Solid X is heated in a boiling tube and the temperature is recorded at regular time intervals. If the melting point of X is 78 oC, which graph represents the heating curve of curve X?
Diagram below shows an air ballon filled with gas X.
In which group is X located in the Periodic Table?
Table above shows the properties of oxides of elements P,Q and R and located in the same period in the Period Table. Arrange the three elements based on the increasing of proton number.
The electron arrangement of atom U is 2.8.1 and atom V is atom 2.8.7. What is the molar mass of a compound formed when atom U combine with atom V?
(RAM: U=23; V=35.5)
Which substances is a covalent compound?
Which diagram shows the electron arrangement for the nitrogen molecule, N2 ?
Compound X has the following properties.
-Insoluble in water
-Has a boiling point of -89 oC
What is compund X?
Table above shows the electron arrangements of atoms P,Q,R and S. Which pair of atoms forms a compound by sharing electron?
Table above shows information about three voltaic cells. Metals X,Y and Z are used as electrodes in the cell.
What is the order of the metals from the most electropositive to the least electropositive?
What is the voltmeter reading when Pand Q are the pair of metals used as electrodes?
Which electrolyte and electrodes can be used to purify copper
0.1 mol dm-3 of solution X has a pH value of 13. Which statement is correct about the solution?
Which of the following is not a chemical property of acids?
A farmer found that his soil is too acidic for some plants to grow well. Which substance is suitable to reduce the acidity of the soil?
The following equation represents the neutralisation between barium hydroxide, Ba(OH)2 and hydrochloric acid, HCl.
Ba(OH)2 + 2HCl → BaCl2 + 2H2O
What is the volume of 0.5mol dm-3 hydrochloric acid needed to neutralise 25cm3 of 0.1mol dm-3 barium hydroxide?
Which equations represents a double decomposition reactions to form a precipitate?
(I) CuSO4 + Na2CO2 → CuCO3 + Na2SO4
(II) CuSO4 + Mg(NO3)2 → Cu(NO3)2 + MgSO4
(III) AgNO3 + NaCl → AgCl + NaNO3
(IV) ZnCl2 + Na2SO4 → ZnSO4 + 2NaCl
When the temperature of a reacting mixture increases, the rate of reaction increases. Which statement explains why the rate of reaction increases?
The following equation shows the reaction of zinc powder and hydrochloric acid.
Zn + 2HCl → ZnCl2 + H2
How can the rate of production of hydrogen be increased?
The following equation represents the complete combustion of a hydrocarbon.
CXH2y + yO2 -> xCO2 + yH2O
Which of the following are the values of x and y?
Which of the half equations represents the reactions at the anode(A) and the cathode(C)?
What is X?
What is te rate of reaction?
Which structural formulae are isomers of butane?
What happens when natural rubbers is vulcanised?
When but-2-ene is shaken with bromine water then decolourised. What is the product of this reaction?
Which statement is correct about alkanes ?
Which structural formula does not correspond to the named compound?
Which statement defines oxidation?
Which metal can prevent rusting when is it in contact with iron?
What is the oxidation number of X in X2O32- ion?
Based on the equation, which statement is correct?
100 cm3 of water is heated by the burning of a sample of ethanol. The heat released by the combustion is 10.5 kJ. What is the maximum increase i temperature of water?
(Specific heat capacity of water= 4.2 J g-1 oC-1)
What is meaning of heat of neutralisation?
Which pair is matched correctly?
Ammonium sulphate is used as a fertiliser. What is the percentage by mass of nitrogen in ammonium sulphate?
(RAM: H=1; N=14; O=16; S=32)
In order to produce a glass that is more resistant to heat and chemicals, substances X is added to soda lime glass.
What is X?
Which substances is a natural polymer?
Which substance is a composite material?
Why sodium chloride used in the preparation of soap?