3.1. Formulae
A subsection of Chemistry, 0620, through 3. Stoichiometry
Listing 10 of 91 questions
The following are the symbols and formulae of some elements and compounds. Ar Ca(OH)2 Cl 2 CO2 Cu Fe SO2 V2O5 Answer the following questions using only the elements or compounds in the list. Each element or compound may be used once, more than once or not at all. State which element or compound is used: to kill bacteria in drinking water as a food preservative as an electrical conductor in cables as an inert atmosphere in lamps to neutralise excess acidity in soil as a catalyst in the Contact process.
0620_s18_qp_43
THEORY
2018
Paper 4, Variant 3
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A list of symbols and formulae is shown. Br – CH4 CO2 Cu2+ H2 K+ Na+ N2 O2 U Answer the following questions using these symbols or formulae. Each symbol or formula may be used once, more than once or not at all. State which symbol or formula represents: a compound that is a product of respiration an ion that gives a lilac colour in a flame test a gas which is 21% of clean, dry air an element that has a radioactive isotope used as a source of energy an ion formed when an atom gains an electron. Complete the table to show the relative masses of a proton, a neutron and an electron. type of particle relative mass proton neutron electron  Choose the two correct statements about carbondioxide. Tick (✓) two boxes. Carbon dioxide is a mixture of two elements. Carbon dioxide is an acidic oxide. Carbon dioxide has ionic bonding. Carbon dioxide has a giant covalent structure. There are three atoms in a molecule of carbon dioxide.  
0620_s22_qp_32
THEORY
2022
Paper 3, Variant 2
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Questions Discovered
91